The significance of content knowledge for informal reasoning regarding socioscientific issues: Applying genetics knowledge to genetic engineering issues

The Significance of ContentKnowledge for InformalReasoning RegardingSocioscientific Issues: ApplyingGenetics Knowledge to GeneticEngineering Issues

TROY D. SADLERDepartment of Curriculum and Instruction, Indiana University, 201 N. Rose Avenue,Bloomington, IN 47405-1006, USA

DANA L. ZEIDLERDepartment of Secondary Education, University of South Florida, 4202 E. Fowler Avenue,Tampa, FL 33620, USA

Received 24 November 2003; revised 9 February 2004; accepted 5 March 2004

DOI 10.1002/sce.20023Published online 26 August 2004 in Wiley InterScience (www.interscience.wiley.com).

ABSTRACT: This study focused on informal reasoning regarding socioscientific issues.It sought to explore how content knowledge influenced the negotiation and resolution ofcontentious and complex scenarios based on genetic engineering. Two hundred and sixty-nine students drawn from undergraduate natural science and nonnatural science coursescompleted a quantitative test of genetics concepts. Two subsets (n = 15 for each group)of the original sample representing divergent levels of content knowledge participated inindividual interviews, during which they articulated positions, rationales, counterpositions,and rebuttals in response to three gene therapy scenarios and three cloning scenarios. Amixed-methods approach was used to examine the effects of content knowledge on the useof informal reasoning patterns and the quality of informal reasoning. Participants from bothgroups employed the same general patterns of informal reasoning. Data did indicate thatdifferences in content knowledge were related to variations in informal reasoning quality.Participants, with more advanced understandings of genetics, demonstrated fewer instancesof reasoning flaws, as defined by a priori criteria, and were more likely to incorporate contentknowledge in their reasoning patterns than participants with more naıve understandings ofgenetics. Implications for instruction and future research are discussed. C© 2004 WileyPeriodicals, Inc. Sci Ed 89:71–93, 2005

Correspondence to: Troy Sadler; e-mail: [email protected]

C© 2004 Wiley Periodicals, Inc.

72 SADLER AND ZEIDLER

INTRODUCTION

Modern science and the societies from which it arises share a complex interdependence.Scientific research agendas are frequently based on the perceived needs of society. Society,in turn, often benefits from research products of the scientific enterprise. This simplifieddescription of science and society suggests a relatively straightforward interaction: societycreates needs and scientists seek to identify, prioritize, and generate solutions for thoseneeds. Of course, this pattern only describes one possible association. In other instances,the pursuit and development of science may help shape and influence the development ofsocial norms. Yet more likely than either of these two simplified paths lies a more complexmodel which subsumes both descriptions. A case in point may be found in moleculargenetics and genetic engineering, which illustrate the multifaceted interdepence of scienceand society. For example, basic biochemical research on DNA has made it possible forscience and society to consider the possibility of altering heredity. Perceived social needssuch as a desire to eliminate disease and improve agricultural productivity have led scientiststo develop techniques for harvesting stem cells and genetically modifying organisms. Thesetechnologies have resulted in a host of ethical quandaries and the development of new socialnorms with which society must now struggle.

The issues that evolve from the complex interactions of science and society have beentermed socioscientific issues (SSI) (Kolstø, 2001a; Zeidler et al., 2002), and many scienceeducators have made a case for including SSI in the canon of school science (Bingle &Gaskell, 1994; Driver, Newton, & Osborne, 2000; Pedretti, 1999; Sadler & Zeidler, 2004;Zeidler & Keefer, 2003; Zohar & Nemet, 2002). This perspective suggests that the ability tonegotiate and resolve SSI represents an integral component of scientific literacy as describedby standards and reform documents in the United States (American Association for theAdvancement of Science, 1990; National Research Council, 1996; Siebert & McIntosh,2001) and abroad (Council of Ministers of Education Canada Pan-Canadian Science Project,1997; Millar & Osborne, 1998; Queensland School Curriculum Council, 2001).

THEORETICAL FRAMEWORK

Informal Reasoning

Socioscientific issues can be particularly difficult for individuals to negotiate, in part,because they are open-ended, ill-structured problems which are typically contentious andsubject to multiple perspectives and solutions. The negotiation and resolution of such com-plex problems can be characterized generally by the process of informal reasoning (Sadler,2004a; Sadler & Zeidler, in review). Individuals engage in informal reasoning as they at-tempt to work out contentious problems without clear-cut solutions (Kuhn, 1991; Means &Voss, 1996; Perkins, Farady, & Bushey, 1991). Informal reasoning as a construct subsumesthe cognitive and affective processes that contribute to the resolution of complex issues.In an article discussing student thinking regarding human genetics dilemmas, Zohar andNemet (2002) describe the concept:

It [informal reasoning] involves reasoning about causes and consequences and about advan-tages and disadvantages, or pros and cons, of particular propositions or decision alternatives.It underlies attitudes and opinions, involves ill-structured problems that have no definitesolution, and often involves inductive (rather than deductive) reasoning problems. (p. 38)

Because socioscientific issues are open-ended, ill-structured, debatable problems, we usethe term informal reasoning to describe how individuals negotiate and resolve them.

SIGNIFICANCE OF CONTENT KNOWLEDGE 73

Individuals can express informal reasoning through dialogical argumentation (Driver,Newton, & Osborne, 2000; van Eemeren et al., 1996); however, informal reasoning andargumentation represent unique constructs. Informal reasoning refers to the cognitive andaffective processes involved in the negotiation of complex issues and the formation oradoption of a position. Argumentation refers to the expression of informal reasoning.The problem with this distinction lies in the fact that the constructs are practically in-distinguishable from an empirical perspective. Argumentation is the means by which re-searchers gain access to informal reasoning, but they must do so with some trepidation.While it is valid to assert that strong argumentation reveals strong informal reasoning,the opposite claim, weak argumentation denotes weak informal reasoning, is not nec-essarily the case. Adept arguments must be based on proficient informal reasoning, butnaıve arguments might be the result of either insufficient informal reasoning or poorlyarticulated, but proficient informal reasoning (Means & Voss, 1996). An investigation ex-pressly focused on argumentation need not be burdened by the discrepancy; however, astudy of informal reasoning through argumentation necessarily assumes the problematicassociation.

Assessments of informal reasoning can focus on at least two unique features: quality andpatterns. Kuhn (1991) whose work draws heavily from Toulmin’s (1958) model of argu-mentation defines informal reasoning quality in terms of coherence, internal consistency,and the ability to perceive multiple perspectives. In other words, an individual displays highquality informal reasoning when s/he articulates coherent arguments that do not contradicthis/her other positions and when s/he is able to analyze those arguments from multipleperspectives. In contrast, deficient informal reasoning could result from unclear or contra-dictory arguments or the inability to conceptualize an issue’s complexity due to reliance ona single perspective.

The phrase “informal reasoning patterns” stems from our previous work with informalreasoning in the context of SSI (Sadler & Zeidler, 2004; Sadler & Zeidler, in review). Wehave found that individuals tend to relate to and resolve SSI through one or more distinc-tive patterns of informal reasoning. Three subsumptive patterns, which have emerged frominterview data, characterize student decision-making: rationalistic, emotive, and intuitiveinformal reasoning. Rationalistic informal reasoning describes reason-based calculations.This class of responses includes applications of deontological and utilitarian principles,cost-benefit analyses, and rational assessments of the limitations of technology. Emotiveinformal reasoning is consistent with the application of moral emotions such as empa-thy and sympathy (Eisenberg, 2000; Hoffman, 2000). The individuals, who have revealedemotive reasoning, seem to genuinely care about the well-being of others. This mode ofinformal reasoning is characterized by a tendency to focus on the human element of issues.Emotive informal reasoning is not necessarily irrational: it is based on emotions, and yet,can reflect rational thought processes. Intuitive informal reasoning describes considerationsbased on immediate reactions to the context of a scenario. Like emotive reasoning, intuitivereasoning is an affective response; but whereas emotive reasoning directs emotion towardthe well-being of others, intuitive reasoning is an unexplainable immediate reaction (Sadler& Zeidler, 2004).

SIGNIFICANCE OF CONTENT KNOWLEDGE

A common assumption made in literature regarding SSI presupposes a link betweeninformal reasoning in the context of a socioscientific issue and content knowledge related tothat issue. On its surface, this certainly constitutes a reasonable claim. It seems intuitivelyobvious that individuals need to have an understanding of an issue in order to render


informed decisions. Patronis, Potari, and Spiliotopoulou (1999) articulate this position asthey discuss SSI decision-making competence: “a lot of knowledge and information needsto be developed about the nature of particular socio-scientific issues” (p. 745). Althoughit is not always explicitly stated, many authors operate under this assumption (Dawson& Schibeci, 2003; Jimenez-Aleixandre, Rodrıguez, & Duschl, 2000; Leighton & Bisanz,2003; Martinez-Gracia, Gil-Quilez, & Osada, 2003; Pedretti, 1999; Yang & Anderson,2003). Copland (2003), a biochemist discussing the nature of bioethics, goes so far as toassert that only those individuals with expert understandings of science can meaningfullycontribute to SSI debates. “The reactions of non-specialist observers to complex ethicalproblems raised by cutting-edge science such as embryonic stem-cell research are no morejustified or useful than their opinions about the technical difficulties yet to be overcome”(p. 121). This is certainly not a position that we espouse, on the contrary, we contend thatthoughtful negotiation of SSI is integral for all citizens of modern societies, not just thefew who work as professional scientists (Sadler, 2004b; Zeidler & Keefer, 2003). However,this quotation illustrates an extreme formulation of a proposition that will be explored inthis study: advanced conceptualizations of relevant content knowledge lead to improvedinformal reasoning regarding SSI.

If most research related to socioscientific decision-making presumes a positive relation-ship between content knowledge and informal reasoning quality and this presumption issupported conceptually, critics may question the need for an empirical investigation of theseconstructs. Despite the intuitive appeal of a direct relationship between knowledge and rea-soning ability, research findings within the domain of informal reasoning do not provideconvincing support. In a review of studies of reasoning and argumentation, Kuhn (1991)concludes that “the data show that a large sophisticated knowledge base in a content do-main does not determine the quality of thinking skills used in the domain” (p. 39). Perkins,Farady, and Bushey (1991) report on a series of studies in which students from various gradelevels reasoned about issues they might encounter in everyday life with conceptual ties tovarious content domains. The researchers found no significant relation between the qualityof reasoning and understanding of related content knowledge. In a study of content knowl-edge and argumentation, Means and Voss (1996) concluded that content knowledge didaccount for a greater number of participant responses, but these quantitative differences didnot necessarily lead to the formulation of higher quality arguments indicative of advancedinformal reasoning.

We are not aware of studies which have specifically focused on the potential link be-tween informal reasoning regarding SSI and content knowledge; however, a number ofinvestigations have produced results that at least tangentially address the topic. Zohar andNemet (2002) conducted an intervention study that integrated explicit teaching of argumen-tation into an instructional unit on human genetics. The participating students demonstratedsignificantly improved performance on assessments of both content knowledge and argu-mentation quality. These authors assert that argumentation represents the means by whichinformal reasoning can be accessed. In other words, argumentation is the expression of infor-mal reasoning, which is a position consistent with the theoretical framework underlying thepresent study. Given that the intervention addressed both science content and argumentationskills, conclusions can not be drawn about the independent effects of content knowledge.However, participants in a control group which only received content knowledge instruc-tion demonstrated knowledge gains but no improvements in argumentation. This resultimplies that argumentation skills do not necessarily improve with greater content knowl-edge. The distinction between argumentation and informal reasoning is important becauseit remains possible for individuals’ informal reasoning to improve without a correspond-ing improvement in argumentation. Therefore, the conclusion that argumentation skills


were independent of knowledge gains does necessarily preclude a link between informalreasoning and content knowledge, but this study does not support such a link.

Other research has produced results more supportive of the intuitive relationship betweencontent knowledge and informal reasoning. Fleming (1986a, 1986b) explored student rea-soning as expressed in semi-structured interviews focused on a variety of SSI. He reportedthat the great majority of participants (91%) mentioned scientific terminology, but very fewactually incorporated scientific knowledge in any meaningful ways. Fleming concludedthat the students’ lack of knowledge inhibited their reasoning regarding the issues. Tytler,Duggan, and Gott (2001) presented a case study of a community struggling with a local en-vironmental problem. The primary focus of this report was an examination of how differentstakeholders, both scientists and the lay public, assessed and used scientific evidence. Theresults suggested that the members of the laity were unable to draw on content knowledgewhich could have potentially strengthened their positions. As in Fleming’s (1986a, 1986b)study, these participants’ lack of knowledge limited the quality of their informal reasoning.

Whereas Fleming (1986a, 1986b) and Tytler et al. (2001) support the association ofcontent knowledge and informal reasoning with negative cases, Hogan (2002) and Zeidlerand Schafer (1984) offer evidence of a positive relationship. Hogan (2002) compared thereasoning of eighth grade students, working in small groups, with that of an ecologist inthe context of environmental management dilemmas. Not surprisingly, the reasoning ofthe professional scientist revealed a richer collection of background knowledge, a greaterappreciation for pertinent issues, and more sophisticated justifications and explanation.The author suggested that the limited knowledge of student groups, as compared to theknowledge of the scientist, restricted the group’s ability to consider multiple factors leadingto their relatively naıve management decisions. Concluding that middle schoolers do notreason about environmental issues as well as environmental scientists is not particularlysignificant; however, a trend related to the link between informal reasoning and contentknowledge developed among the student groups. Whereas most groups were relatively het-erogeneous in terms of their understanding of ecological content knowledge, as assessedby student performance in a content-focused interview, members of one group scored ex-ceptionally well on the knowledge assessment. This group clearly “displayed the most inte-grative and thorough reasoning” (p. 363) throughout the investigation as compared to theirpeers.

Zeidler and Schafer’s (1984) work also substantiates the link between content knowledgeand informal reasoning. The researchers selected two groups of undergraduates for theiranalysis: environmental science majors and nonscience majors. Each of the participantscompleted a series of assessments related to moral reasoning, and environmental issue affectand knowledge. Whereas the science majors scored higher on the content knowledge test,both groups displayed positive attitudes toward the environment. No significant differencesbetween the groups emerged in response to a general measure of moral reasoning, but thescience majors outperformed the nonscience majors on a measure of moral reasoning inthe context of environmental issues (i.e., Environmental Issues Team (EIT)). The fact thatboth groups displayed positive attitudes toward the environment suggested that differencesin content knowledge contributed to the disparity in moral reasoning, in environmentalcontexts. By revealing the context dependence of moral reasoning, Zeidler and Schafer(1984) uncovered a possible relationship between conceptual understanding of materialand moral reasoning regarding issues related to that material. While moral reasoning, thetarget of EIT scores, is not synonymous with informal reasoning, moral reasoning forms anintegral part of informal reasoning (Andrew & Robottom, 2001; Solomon, 1994; Zeidler,1984); therefore, it follows that content knowledge may be an important variable for informalreasoning.


RESEARCH FOCUS

Many of the studies just described provide tangential evidence for the presumed relation-ship between informal reasoning and content knowledge in the context of socioscientificissues. However, this conclusion is not supported by literature reviews from the broader do-mains of informal reasoning and argumentation (Kuhn, 1991; Means & Voss, 1996; Perkins,Farady, & Bushey, 1991). The transfer, presupposed by many science educators, of basicscience knowledge in the context of socioscientific issues is not endorsed by more generaltreatments of transfer (Haskell, 2001) and has yet to be rigorously tested. The purpose ofthis study is to address the extent to which content knowledge is related to both the patternsand quality of informal reasoning regarding socioscientific issues. More specifically theresearch is guided by the following questions:

1. How is understanding of science content underlying a socioscientific issue related tothe quality of a decision-maker’s informal reasoning regarding that issue?

2. How is understanding of science content underlying a socioscientific issue related topatterns of informal reasoning displayed in the context of that issue?

The first research question prescribes an investigation of the relationship between contentknowledge and informal reasoning quality. In addressing this question, we explore thefrequently assumed positive correlation between how well an individual understands contentrelated to an issue and the quality of informal reasoning s/he displays when confrontingand resolving that issue. The second research question focuses on the relationship betweenparticipant content knowledge and the informal reasoning patterns s/he displays. It couldbe hypothesized that individuals with higher levels of content knowledge in genetics aremore likely to engage in rationalistic informal reasoning (as opposed to emotive or intuitiveinformal reasoning) than their peers who possessed lower levels of content knowledge.This is one of many possible associations we address by assessing the relationship betweencontent knowledge and informal reasoning patterns.

METHODS

This study calls for the exploration of three variables in the context of socioscientificissues: content knowledge, informal reasoning patterns, and informal reasoning quality.We used a mixed-methods approach to access and analyze relationships among the three.In order to elicit argumentation as a means of empirically accessing informal reasoningpatterns and quality, we engaged participants in interviews and explicitly asked them toformulate positions in response to a series of related SSI. This technique is consistent withother more general investigations of informal reasoning (Kuhn, 1991; Means & Voss, 1996;Perkins, Farady, & Bushey, 1991) as well as those specifically targeting SSI (Kolstø, 2001b;Sadler & Zeidler, 2004; Zeidler et al., 2002). As mentioned in the theoretical framework,empirical distinctions between informal reasoning and argumentation can be difficult todraw but remain methodologically possible. If we were expressly interested in argumenta-tion skills, we could have asked participants to offer arguments without prompts specifyingtheir attention to argument structures such as counterpositions and rationales. We could havealternatively observed as the participants engaged in argumentation with peers. Because wewere interested in the informal reasoning that underlies argumentation and not argumen-tation per se, we imposed much more structure on our interactions with the participants.Rather than allowing students to demonstrate argumentation forms they may naturally use,we asked participants to offer specific argument structures such as positions, rationales,


counterpositions, and rebuttals. By using this approach we did not assess argumentationskills, but rather elicited comments reflective of their informal reasoning. We did not focuson what participants might offer through normal discourse; we used specific questions andprobes to assess what students could say as a result of their informal reasoning. This ap-proach allowed us to reveal evidence of unarticulated reasoning and implicit justificationsthat would not otherwise be revealed had we focused on argumentation rather than informalreasoning.

During the interviews, participants were asked to consider and resolve six scenarios.Each of the scenarios could have stemmed from unique SSI, but this approach would havemade the assessment of relevant content knowledge problematic. Presenting six scenarioswhich all related to a shared body of knowledge made our research goals more feasible.We chose to use issues in human genetics as the context for all of the interview scenarios.Three of the scenarios dealt with gene therapy, while the others concentrated on cloning(see Appendix for each of the six scenario prompts used in the interviews). Although eachof the scenarios provided unique opportunities for the participants to express patterns ofinformal reasoning, all were based on a common set of scientific concepts, namely, basicgenetics concepts.

The individual interviews were semi-structured, conducted in a private office, and audio-recorded for transcription. For each of the six scenarios to which participants responded,the first author presented a written description (see Appendix) and asked the participantto offer a position. For instance, one scenario involved an infertile couple who wanted tohave children. The participant was asked whether s/he approved of cloning in this context.The first author then posed questions designed to elicit a rationale to support the position,a counterposition (an argument which opposed the participant’s original position), and arebuttal to the counterposition. When the participant was unable to articulate a counterposi-tion, the first author offered a possible suggestion so that s/he had an opportunity to providea rebuttal. The information sought in the interviews was informed by research in argumenta-tion and informal reasoning. More specifically, the interview protocols were based, in part,on Kuhn’s (1991) study of informal reasoning, which in turn, was influenced by Toulmin’smodel for the analysis of argumentation (Toulmin, 1958).

Each of the participants also participated in a follow-up interview. These interviews gavethe participants an opportunity to reflect on preliminary interpretations of their responses ar-ticulated in the first interviews. The participants were not asked to comment on assessmentsof informal reasoning quality, but rather, the content and meaning of their responses. Thefollow-up interviews also enabled the researchers to ask students about factors which mayhave influenced the positions they held. Sadler and Zeidler (in review) present a detaileddiscussion of interview protocols.

Assessing Informal Reasoning

In order to assess informal reasoning quality, we developed a priori criteria, consistentwith the theoretical framework, for analyzing participant responses to each of the sociosci-entific scenarios. Four criteria defined the framework: intrascenario coherence, interscenariononcontradiction, counterposition construction, and rebuttal construction (see Table 1). In-trascenario coherence addressed the extent to which rationales offered supported the statedposition for any one scenario. Interscenario noncontradiction addressed whether the po-sitions and rationales advanced in response to one scenario contradicted the argumentsoffered in response to related scenarios (cloning or gene therapy scenarios). In order to benoncontradictory, positions did not necessarily have to be identical; for instance, a partici-pant might have supported the use of cloning in one context and opposed it in another but


TABLE 1Criteria Used for Assessing the Quality of Informal Reasoning

Criterion Description

Intrascenario coherence Does the rationale support the stated position?Interscenario

noncontradictionAre the positions and rationales from each of the three

related scenarios (i.e., three cloning scenarios andthree gene therapy scenarios) noncontradictory withone another?

Counterposition construction Can the participant construct and explain acounterposition?

Rebuttal construction Can the participant construct a coherent rebuttal?

maintained consistency by providing rationales that did not directly oppose one another.For example, a participant might have opposed gene therapy in one context because “it feelsmorally wrong” and supported gene therapy in another context because “it has the potentialto help people.” Because of the contextual nature of the scenarios, these positions did notnecessarily contradict one another. However, a person, who opposed gene therapy because“people should not alter the natural order” in one context and supported gene therapy inanother context because “it helps people,” presented a contradiction. In the first case, eachof the rationales were tied to a particular context and, therefore, did not contradict oneanother. However, in the second case, the contention that gene therapy should be avoidedbecause it alters the natural order transcended the context of a particular scenario; therefore,the expression of support for gene therapy in another context was contradictory to the initialassertion. Counter-position and rebuttal construction addressed whether a participant couldarticulate either of these argument structures.

The informal reasoning patterns (i.e., rationalistic, emotive, and intuitive) employed bythe participants in this study are described in Sadler and Zeidler (in review). Examplesof each informal reasoning pattern can be found in Table 2. It should be noted that manyparticipants tended to employ multiple informal reasoning patterns.

TABLE 2Examples of Each Informal Reasoning (IR) Pattern

IR Pattern Example

Rationalistic Right now, there is a black market for organs so if you could create anorgan [by means of therapeutic cloning], then that would bejustifiable. The ends justify the means kind of thing . . . You have toweigh all the options and decide whether it is worth the risk.

Emotive [Gene therapy for Huntington’s disease] looks like it would take awayfrom someone having to suffer for 20 years, and then you would nothave to die so early either. So, I think it is a good idea. It couldincrease your life span . . . I do not like to see people suffer and ifthere’s something like this that can eliminate it, then why not?

Inutuitive I just do not think that it [human cloning] is right. I do not really knowwhy; it is just this feeling. I do not think it is a good idea. . . I do notknow how to sum it up, but it just does not seem right. I do not haveany specific reasons.


Assessing Content Knowledge

In order to assess participants’ understanding of the science content that underlies humangenetic issues, the study required a test of genetics concepts. A review of the literaturerelated to genetics instruction and testing revealed no preexisting instruments that metour requirements. Therefore, we developed the Test of Basic Genetics Concepts (TBGC).Instrument development began with the identification of target concepts in consultationwith several general biology and genetics textbooks (Campbell, Mitchell, & Reece, 1997;Gardner, Simmons, & Snustad, 1991; Klug & Cummings, 1997; Miller & Levine, 1998)and five content experts (two high school and three college teachers with a minimumof 10 years experience teaching genetics). We constructed 23 multiple-choice questionsdesigned to address each of the predetermined concepts, and the content experts reviewedthem for accuracy and clarity. The test was designed to differentiate between individualswho possessed little to no understanding regarding the mechanisms of human heredity andindividuals who possessed a level of understanding commensurate with the aims of highschool genetics instruction. The TBGC did not distinguish among more advanced levels ofunderstanding that might result from successful completion of college genetics courses.

The instrument was pilot tested with 41 undergraduate students enrolled in a generalchemistry laboratory. Raw scores ranged from 5 (22%) to 23 (100%) items answered cor-rectly. The distribution of scores approximated a normal distribution (skewness = −0.16;kurtosis = −0.45) with a mean of 14.3 and standard deviation of 4.3. Results from thepilot test were also used to assess the instrument’s internal consistency using the Kuder–Richardson estimate (KR20). Given the conservative nature of Kuder–Richardson estimates(Mehrens & Lehmann, 1991), the calculated internal consistency (rxx = 0.79) suggestedthat the TBGC was appropriately reliable. Data derived from the pilot test were also used foritem analyses. The proportion of individuals who answered a particular question correctly(p value) ranged from 0.90 indicating a very easy question to 0.27 indicating a very difficultquestion. The average p value was 0.62 which suggested that the test was appropriatelychallenging for the population sampled (Osterlind, 1989). Point-biserial correlation coef-ficients varied from 0.06 to 0.75. Although all of the correlations were positive indicatingthat there were no questions on which low scoring individuals outperformed high scoringindividuals, seven questions possessed correlation coefficients below 0.25 suggesting thatthese items did not perform as well as anticipated. Each of these items was individually con-sidered for improvement or omission. The final TBGC draft targeted nine genetics conceptsand contained 20 items.

Population and Samples

Undergraduate college students were the target population for the present study. Althoughsocioscientific curricula are appropriate for a wide range of educational levels (includingmiddle school, high school, and college), the college level was chosen because in order todetect the influence of content knowledge on informal reasoning, measurable differencesin content knowledge needed to be obtained. It was more likely that some college studentshad developed sophisticated conceptualizations of genetics than younger students.

Volunteers were recruited, from both natural science (viz., biology) and nonnatural sci-ence (viz., psychology) courses, to take the TBGC. Both types of undergraduate courseswere sampled in order to obtain a wide range of content knowledge. It was hypothesized thatstudents enrolled in classes designed for natural science majors would on average possessa greater understanding of basic genetics concepts than their peers who had chosen othermajors and, therefore, had less coursework in related areas. Although this hypothesis guidedthe selection of the sample, course enrollment was not a variable explored in this study.


Knowledge of genetics was assessed by means of the TBGC. Two hundred and sixty-nineindividuals completed the TBGC, and their raw scores ranged from 2 to 18 (maximumscore = 18). The mean score was 10.09 with a standard deviation of 3.63, and the scoresapproximated a normal distribution (skewness = 0.11; kurtosis = −0.79).

The interviews were conducted with a subsample of the individuals taking the TBGC. Thesubsample was constructed using a maximum variation strategy (Lincoln & Guba, 1985). Inorder to detect differences in informal reasoning as a result of differences in content knowl-edge, individuals with divergent scores on the TBGC participated in the interviews. Resultsfrom the TBGC were used to identify participants with high or low understanding (comparedto the overall sample) of basic genetics. Decisions regarding which scores represented highand low understanding were made post hoc so that maximum variation subsamples could beobtained. Individuals scoring in the 90th percentile or higher comprised the high understand-ing group; whereas individuals scoring in the 25th percentile or lower comprised the lowunderstanding group. These group cut-offs were not symmetrical because we sought equalgender representation within each subgroup. In order to sample relatively equal numbersof males and females in both the high and low understanding groups, we needed to extendthe low understanding cut-off from the 10th to 25th percentile. Thirty volunteers from boththe high and low content knowledge groups (15 representing low content knowledge and15 representing high content knowledge) were solicited to participate in the interviews.

Gender, TBGC scores, and willingness to participate in the interviews were the crite-ria used to select participants for the interviews. During the interviews, each participantcompleted a personal information sheet on which s/he could describe him/herself in termsof age, race or ethnicity, religious affiliation, and areas of study. Table 3 summarizes this

TABLE 3Interview Subsample Characteristic

Genetics Understanding

Low High

N 15 15Gender

F 8 8M 7 7

Race/ethnicityWhite 10 11Black 4 0Hispanic 1 2Asian 0 2

Religious affiliationProtestant 6 5None/atheist 5 5Catholic 3 3Muslim 1 0Hindu 0 1Greek Orthodox 0 1

Area of studyNatural sciencea 1 15Social science 14 0

aThe “natural science” categories include those individuals who reported “pre-medicine” asan area of study.


information. The subsamples were comparable in terms of these characteristics with a fewexceptions. The two groups reported very different areas of study, which was predictedgiven the sampling scheme. Students who identified themselves as White or Caucasiancomprised a majority of both groups, but the low understanding group included four indi-viduals who identified themselves as Black or African American and one who identifiedhim/herself as Hispanic; whereas, the high understanding group included two individualswho identified themselves as Hispanic and two individuals who identified themselves asAsian. These characteristics were not specifically explored as a part of this study, but theyare presented for descriptive purposes.

Data Analysis

To address the two research questions, we compared informal reasoning displayed byindividuals representing high and low genetics understanding. Whereas informal reasoningquality was assessed by means of an a priori framework (see Table 1), the informal reasoningpatterns (i.e., informal, emotive, and intuitive) emerged directly from the data (see Sadler &Zeidler, in review). The extent to which any participant responses met informal reasoningquality criteria or represented informal reasoning patterns was the subject of extensivequalitative analyses. Both authors reviewed 20% of the transcripts independently to evaluatequality and classify the displayed patterns. The rate of corroboration between the two authorsin categorizing participant reasoning for each of the six scenarios exceeded 90%. Based onthis high rate of inter-rater agreement, the first author completed analyses on the remainingtranscripts.

RESULTS

Informal Reasoning Quality

Interview transcripts revealed variability among all four criteria proposed for assessinginformal reasoning quality: intrascenario coherence, interscenario noncontradiction, coun-terposition construction, and rebuttal construction. Table 4 provides examples of interviewexcerpts and how they were assessed according to the quality criteria. (Each quotation isidentified by a code which identifies an individual participant. Codes L1–L15 correspondto participants representing the low understanding group, and codes H16–H30 correspondto participants representing the high understanding group.)

Although each of the assessment criteria was originally intended to illuminate differ-ent aspects of informal reasoning; in practice, they overlapped. For example, intrascenariocoherence was sometimes related to the counterpositions and rebuttals offered. Therefore,rather than attempting to calculate a score corresponding to each criterion, which wouldnecessarily represent dependent measures, we considered all four criteria for a single as-sessment. It clearly would have been advantageous for us to be able to use all four criteriaindependently and, therefore, have a more sensitive measure of reasoning quality. However,we could not reliably parse out assessments of individual criteria. To maintain the integrityof the data and reliability of our assessments, we chose the more conservative route ofconferring a single measure on participant responses to each scenario. If an individual wasnot able to form a coherent position, a counterposition, or rebuttal, or s/he contradicted aposition offered in response to another scenario, that individual’s response was labeled asa position which displayed flawed reasoning. The inability to form any position was alsoconsidered representative of flawed reasoning. Participants responded to six scenarios, andtherefore, could show evidence of flawed reasoning a maximum of six times. Reasoning


TABLE 4Assessment Criteria for Informal Reasoning Quality and Interview ExcerptsThat Demonstrate Examples and Nonexamples

Criterion Example Nonexample

Intrascenariocoherence

H18: I probably do not agree withgene therapy fornearsightedness simplybecause you can correct it byother means. So, why gothrough the problem of tryingto find a single gene toproduce something that youcan deal with by other meansthat are less expensive andless invasive. . . [by using genetherapy] you are messing withyour chromosomes; you aremessing with the wholeindividual. So, you are actuallychanging the individual. Withglasses and stuff, you’re justcorrecting a weakness.

L1: For gene therapy [fornearsightedness], I woulddefinitely say yes. . . If a personcan stop this from happening orsaving their eyesight, I say do it.I have no problem againstit. . . We can cure[nearsightedness] but for theother one [Huntington’sdisease], there is no cure. So, Ibelieve if there is technology tocure something, by all meansdo it, but if there is anotherapproach that we have, thenuse that if it is moreconventional or more practical,use that.

Interscenariononcontradiction

L6: I support this kind of cloning[for reproduction]—I really lovekids and if I could not havekids, that would be one of myoptions because it is the nextbest thing to having your ownnatural birth. . . [But, cloning adead child] is scary. That wouldbe a personal decision. . . Iwould not do it, but if a personchooses to do it, I think theyshould be able to.

L3: I think it is a very sad situationwhen couples can’t havechildren, but imagine if everyperson could not have a childcould now have children. Thepopulation of this planet isgrowing at an alarming ratealready. Maybe there are certainreasons why some peopleshould not have children. . . I donot see why this mother shouldnot [have the right to clone herdead child]. . . I believe peopleshould have a lot more rightsthan they are given in a freecountry. What is one more?

Counterpositionconstruction

L9: No [reproductive cloningshould not be legal], becausethere are so many kids outthere that need adoption. Iknow that, on the other hand, alot of people want to have theirown babies, but I just do notthink that it is right. I do notreally know why—it is just thisfeeling. I do not think it is agood idea.

H20: I feel that when you combinethe egg and sperm—that isimportant for marriage—you arecombining yourselves into one.Children are a combination ofwho you are and what yourmarriage is. . . It [cloning] is notnatural in God’s eyes or in myeyes.

Int: Can you think of argumentthat someone might offer insupport of reproductivecloning?

Continued


TABLE 4Assessment Criteria for Informal Reasoning Quality and Interview ExcerptsThat Demonstrate Examples and Nonexamples (Continued )

Criterion Example Nonexample

Int: Can you think of argument thatsomeone might offer in supportof reproductive cloning?

P9: If someone really wanted tohave their own child. From anemotional perspective, they wantto have their own baby and theyhave dreamed about that forever.If they can’t that would really hurtthem so if they had this option, Ithink they would want to do it.

P20: I don’t think that if you reallywant a baby—it is not going tobe a combination of you two.Why not adopt? I would not havean argument.

Rebuttalconstruction

H17: I think there should be a limiton what gene therapy should beused for. I think it should only beused for things that are big, notsmall things like this [correctingnearsightedness]. So probablynot.

Int: Can you think of argument thatsomeone might offer in supportof gene therapy fornearsightedness?

H17: If we can fix it, why not fix it?Humans have developed a wayof thinking and solving problemsand if we have the ability to fixsomething, then why not? But Ithink that people can get carriedaway with it. I think there shouldbe a line drawn there.

L8: I do not necessarily think thatwe should change genes forsomething like that[nearsightedness]. That issomething that you can dealwith. Contacts and glasses seemto work fine.

Int: Can you think of argument thatsomeone might offer in supportof gene therapy fornearsightedness?

L8: I guess you could look at it anduse finances as an argument. Ifyou did this one time, you wouldnot have to pay for glasses oranything.

Int: How could you respond to thatargument in support of youroriginal position?

L8: I am not really sure. . . I am notsure how to react to that.

quality was assessed based on the number of scenarios to which participants demonstratedflawed reasoning. These “scores” could range from 0, indicating no reasoning flaws andtherefore high reasoning quality, to 6, indicating the maximum number of reasoning flawsand therefore low reasoning quality.

Relationship Between Informal Reasoning Qualityand Content Knowledge

To address the question of whether content knowledge was related to quality of infor-mal reasoning, incidences of flawed reasoning were compared between individuals whoexhibited high levels of genetic understanding (as measured by the TBGC) and those whoexhibited low levels of genetic understanding. Table 5 presents the mean number of rea-soning flaws, by level of understanding, as well as other descriptive statistics. A t-test(α = 0.05) was performed to test the null hypothesis that the incidence of flawed reasoning


TABLE 5Descriptive Statistics for Reasoning Flaws Exhibited in Response to SixSocioscientific Scenarios

Genetics Understanding

Low High

N 15 15Mean 3.07 1.33Standard deviation 1.71 1.05Skewness −0.51 0.51Kurtosis −0.68 −0.74Range 5.0 3.0

was equally as likely among the low and high understanding groups. No evidence suggestedviolation of assumptions (viz., normality, homogeneity of variance, and independence) to anextent that would invalidate the statistical analysis. The results, t(28) = 11.21, p = 0.0023,suggested a statistically significant difference in the number of reasoning flaws committedby individuals representing the high and low genetic understanding groups. Participantsin the low understanding group, on average, exhibited flawed reasoning in half of the sixscenarios they discussed; whereas, participants in the high understanding group, on average,exhibited just over one incidence of flawed reasoning while discussing the six scenarios.

Group Characteristics Other Than Content Knowledge

Group assignment (high or low understanding) was based on TBGC scores. Given thisassignment strategy, it was assumed that individuals in the high understanding group knewmore about basic genetics concepts than their peers in the low understanding group. Bothgroups were composed of undergraduate students sampled from the same university, but allof the high understanding participants were recruited from natural science classes; whereas,the low understanding participants were recruited from nonnatural science classes. There-fore, level of genetics understanding was not necessarily the only characteristic which differ-entiated the two groups. Conclusions regarding the relationship between content knowledgeand quality of informal reasoning must be tempered with the fact that differences in contentknowledge were probably not the only factor differentiating the two groups.

One difference, not directly related to genetics knowledge, did emerge between thegroups throughout the course of interviews. Many of the natural science students respondedto scenarios with an evolutionary perspective. These individuals actively considered howgene therapy and cloning would affect the evolutionary trajectory of human populations.Whereas over half of the science students noted evolutionary consequences of genetictechnologies, none of the nonnatural science students made statements indicative of anevolutionary perspective. The quotes that follow were taken from natural science studentinterview transcripts that typified the evolutionary perspective just described.

H24: If you were not genetically fit to do it [have children], then you would not be able todo it. Because they were not genetically fit and their genome was defective, you would notwant to pass that down to someone else, and you would if you use cloning . . . Basically itis just like the theory of evolution and the survival of the fittest. If you are not fit, you arenot going to reproduce.


H25: It boils down to picking and choosing the kind of child you ultimately want. That Ithink would actually have negative effects on the species as a whole. You know, naturalselection—the people who are more intelligent and the people with more physical staminaare better able to deal with the environment. Those are the ones that are going to survive—Ithink altering that could potentially be a bad thing.

H26: If you take this from nature’s point of view—if an individual does not have the abilityto have children, any animal for that matter, that means there is something wrong with theorganism. So whatever they pass on to the next generation is still going to be somehowaffected.

These quotes and the others they represent describe at least one difference betweenthe high and low understanding groups not accounted for by the differences in geneticsknowledge. This evidence suggests that not only has the study of science lead to increasedunderstanding of genetics, it also fostered the development of an evolutionary perspectivewhich became significant in the discussion of socioscientific issues. It should be emphasizedhere that the tendency to use an evolutionary perspective was not interpreted as evidencefor higher quality reasoning; rather, we identify this tendency as an example of one of theways the two subsamples differed from one another in addition to content knowledge.

Evidence of Content Knowledge

Although genetic understanding was not the only difference between the two groups,qualitative evidence emerged to suggest that differences in content knowledge at least con-tributed to the disparities observed in informal reasoning. Most of the participants fromhigh understanding participants showcased relevant content knowledge throughout theirinterviews adding to the richness of the informal reasoning they expressed. Positions, ra-tionales, counterpositions, and rebuttals were clearly enhanced, and in some cases madepossible by the application of content knowledge. The reverse pattern was not observed;low understanding participants did not demonstrably integrate content knowledge in theirresponses. The following excerpts, taken from interview transcripts with the high under-standing participants, demonstrated instances in which content knowledge contributed totheir informal reasoning.

H24: I guess it [the gene for Huntington’s disease] does not exhibit pleiotropy. The Hunt-ington’s gene does not cause you to be less intelligent—it does not have any other effects.Like there are other diseases that when you fiddle with one enzyme, you change anotherwhole pathway. But with this one, from what I know, this mutation is a single gene thatdoes not affect other things.

H26: There are procedures that can take care of this [nearsightedness]. Besides, having thisgene does not mean you’re going to express it. It means that you are probably more subjectto something like that.

H30: If you knew you had [Huntington’s disease] and it is dominant, then I guess—well, Iguess it [the chance of having children with Huntington’s] would be about 50% if you wereheterozygous for it. So, not all your children would be diseased.

Alternative Interpretations

An alternative interpretation of this data is that the two groups differed not only in ge-netics content knowledge, but also in context knowledge. It could have been the case that


the high understanding group, composed of natural science students, had been exposed togenetic engineering issues with more frequency than the low understanding group, com-prised of nonnatural science students, and therefore, possessed a greater understanding ofthe issues’ contexts. It could be reasonably presumed that science students were more likelyto encounter the arguments surrounding genetic engineering than psychology students. Wecannot conclude that none of the differences in informal reasoning quality resulted fromcontext knowledge, as opposed to content knowledge; however, we believe that the evidencerevealed in this study supports the conclusion that content knowledge did, in fact, contributeto and temper differential performances. As the interview excerpts included above reveal,we clearly observed instances in which the genetics knowledge of the high understandinggroup enhanced the informal reasoning expressed. Furthermore, interview data did not sug-gest systematic differences by level of understanding in the degree of exposure to the issuespresented. Some of the low understanding participants did offer statements indicative oflimited exposure to the issues of genetic engineering such as, “I don’t really know enoughto say why you should do it [gene therapy for Huntington’s disease]” (L2) and “if I knewmore about what I was talking about, then I could make a better argument” (L11). However,the interviews from these participants revealed not only a lack of context knowledge, butalso a dearth of content knowledge to help negotiate the context.

The issue of student exposure to the context of the interview prompts was discussedin the follow-up interview. An interviewer asked about how the participants might haveencountered genetic engineering issues prior to the first interview. The responses wereconsistent across both high and low understanding groups. Only one individual from thehigh understanding group reported that genetic engineering had been covered extensivelyin his/her classes. Both groups of participants reported predominant exposure to the issuesthrough the media and personal discussions with friends and family members. A majorityof students in both groups reported learning about cloning and gene therapy through newsprograms (such as Dateline and 20/20), popular magazines, and newspaper articles.

L10: I have seen things in newspapers about this kind of thing [genetic engineering]. It hasalways been an interest to me . . . When I see these articles, like the sheep cloning, I readthem.

H21: Most of my information about the technical side—like how successful it is—was fromreading magazines and newspapers and seeing it on TV.

In addition to media outlets, participants frequently mentioned discussing these issueswith personal acquaintances. In some cases, the discourse seemed to be motivated bypersonal involvement. For instance, a few participants knew individuals struggling withinfertility and had discussed reproductive technologies including the potential of cloning.Other participants had encountered individuals with severe medical conditions and haddiscussed gene therapy or therapeutic cloning options. In other instances, discourse related togenetic engineering stemmed from genuine interest of the participant or their acquaintances.The quotations below, given in response to interview questions related to what influencedthe participants’ positions, exemplify these tendencies.

L5: My mother talks about these issues [genetic engineering]—that comes into play [in theformation of my own ideas]—she works in a doctor’s office.

H29: I know some families that have gone through the [Huntington’s] disease process andthere is nothing that anyone can do except make the patient comfortable . . . There is no wayof preventing it unless you change the genes.


Context knowledge certainly has the potential to contribute to informal reasoning andargumentation, and it is likely that context knowledge varied among the individual par-ticipants in this study. However, the data did not suggest systematic differences by levelof understanding in the kinds of experiences participants had dealing with genetic engi-neering issues. The university at which the study was conducted did offer a senior levelbiology course specifically devoted to the exploration of biotechnology and genetic engi-neering; however, none of the participants in this study had taken the course. It did notappear as though the high understanding students’ participation in biology coursework hadsignificantly altered their exposure to genetic engineering issues beyond what they had ex-perienced generally as a member of Western society. Although the quantitative differencesin informal reasoning quality can not be solely ascribed to differences in knowledge aboutgenetics, qualitative analyses supported the notion that differences in knowledge at leastcontributed to the disparity in informal reasoning quality.

Informal Reasoning Patterns

The interview data produced no noticeable qualitative patterns that distinguished in-dividuals with high levels of genetics knowledge from those with relatively low levelsof genetics knowledge in terms of the reasoning patterns (i.e., rationalistic, emotive, andintuitive informal reasoning) they demonstrated. Because the use of the three different rea-soning patterns was not independent (e.g., rationalistic reasoning could be accompaniedby emotive and/or intuitive reasoning) computing inferential statistics such as a chi squareanalysis of differences was not appropriate. However, the number of individuals, separatedby level of genetics understanding, who employed each informal reasoning pattern acrossall scenarios, is presented in Table 6 for descriptive purposes. Although the proportions ofinformal reasoning pattern reliance fluctuated widely across the scenarios, the proportionof individuals using any one mode of informal reasoning remained relatively constant be-tween the high and low understanding groups. As Table 6 reveals, the paired combinationswere not identical, but they did not mark differences suggestive of any systemic variationin reliance on informal reasoning patterns between participants with high and low levelsof genetics understanding. This study produced no evidence, qualitative or quantitative,to support the notion that individuals with varying levels of content knowledge possesseddifferential tendencies in employing rationalistic, emotive, or intuitive informal reasoningfor the negotiation and resolution of socioscientific issues.

TABLE 6The Number of Individuals Exhibiting Modes of Informal Reasoning to EachScenario by Level of Genetics Understanding

Socioscientific Scenarios

1 2 3 4 5 6 TotalsMode ofInformal

Reasoning L H L H L H L H L H L H L H

Rationalistic 9 13 14 15 15 15 12 14 9 15 13 14 72 86Emotive 12 12 2 2 2 1 11 7 7 8 12 9 46 39Intuitive 1 0 1 0 3 6 6 9 8 7 3 1 22 23

Note: Scenarios 1–3 related to gene therapy, and scenarios 4–6 related to cloning (seeAppendix). “L” represents the low understanding group; “H” represents the high understand-ing group.


Informal Reasoning Patterns and Quality

The research questions identified earlier did not call for an exploration of potential re-lationships between informal reasoning patterns and quality; however, the presentation ofthese two variables opens the possibility for investigating covariation. The interview datamake this an empirically difficult task. Participants frequently displayed multiple reasoningtendencies, in response to the same scenario. When reasoning patterns were integrated,the assessment of qualitative differences among the patterns was impossible. Even thoughmost students employed multiple reasoning patterns simultaneously while resolving socio-scientific issues, in some instances, participants relied on a single reasoning pattern for theresolution of a particular scenario. Therefore, it remained theoretically possible to comparethe quality of informal reasoning as influenced by rationalistic, emotive, and intuitive con-siderations. However, no noticeable differences emerged in the quality of reasoning amongindividuals employing different modes of reasoning for a particular scenario. Furthermore,the limited number of cases, in which only one mode of reasoning was exhibited, prohibitedany quantitative analyses using the informal reasoning constructs (i.e., intrascenario coher-ence, inter-scenario noncontradiction, counterposition construction, rebuttal construction,and scientific accuracy) originally proposed as a means of evaluating quality.

The results from this study cannot rule out any possible connection between patterns(i.e., rationalistic, emotive, and intuitive) and quality of informal reasoning; however, thedata reveal no evidence to support any such connection. Furthermore, the fact that partici-pants tended to integrate multiple modes of informal reasoning suggested that this line ofquestioning was theoretically unimportant.

DISCUSSION

The findings presented herein support the notion that understanding content knowledgeis related to the quality of informal reasoning regarding socioscientific issues based on thatcontent knowledge. More specifically, genetics understanding was related to the qualityof informal reasoning displayed in response to gene therapy and cloning scenarios. Indi-viduals with a strong understanding of genetics demonstrated fewer informal reasoningflaws (as defined by intrascenario coherence, inter-scenario noncontradiction, counterposi-tion construction, and rebuttal construction) than individuals who did not possess a strongunderstanding of genetics. Distinctions in content knowledge were assessed by means ofthe Test of Basic Genetics Concepts, which was validated by content experts and pilot-tested. Although the groups selected to participate in the interview differed in terms ofgenetics content knowledge, they probably also differed regarding other characteristics notaccounted for in this study. In fact, the interviews revealed at least one difference: a ten-dency for individuals in only one (high understanding) of the two groups to consider thesocioscientific scenarios with an evolutionary perspective. However, even though the twogroups might have varied in several ways, the degree of understanding content knowledgeseemed to at least contribute to discrepancies in informal reasoning quality. This conclusionis supported by evidence again revealed throughout the interviews. Whereas participantsin the low understanding group frequently cited a lack of content knowledge as a directcontributor to their inability to answer some of the interview questions, participants in thehigh understanding group explicitly referenced content knowledge which contributed to thequality of their arguments.

This conclusion lends credence to a pattern that had been suggested in previous studies.Fleming (1986b) and Tytler et al. (2001) concluded that a lack of understanding of contentmaterial hindered the ability of the participants in the studies to demonstrate high quality


reasoning. Hogan (2002) reported that students with the greatest understanding of contentknowledge displayed the highest quality argumentation and informal reasoning. Finally,Zeidler and Schafer (1984) found that mastery of content knowledge was related to improvedmoral reasoning. These previous reports supported the claim that content knowledge wasrelated to informal reasoning tangentially, but none focused specifically on this question.The present study, which more directly assessed the association of content knowledge andinformal reasoning quality, supports a positive relationship between the two variables.

Although this conclusion seemed intuitively evident, it was relatively novel in the broadercontext of literature on informal reasoning. In reviews of informal reasoning, both Kuhn(1991) and Perkins et al. (1991) reported that most empirical data fail to support the linkbetween content knowledge and reasoning ability. Means and Voss (1996) reported differ-ences in informal reasoning as a function of content knowledge, but these differences did notcorrespond to quality of informal reasoning. Whereas Means and Voss (1996) revealed dif-ferences, the present study found directional differences. That is, increased content knowl-edge was related to higher quality informal reasoning. This discrepancy between studies ofinformal reasoning in response to SSI and more general treatments of informal reasoningis most likely due to the context of the experimental tasks. Theoretical formulations andassessments of informal reasoning are generally consistent across these bodies of research;the primary difference stems from the type of prompts to which participants are asked torespond. The context of SSI seems to mandate the application of content knowledge for theimprovement of reasoning; whereas, more general tasks associated with the cited studiesof informal reasoning seem less content dependent.

In terms of the applicability of this conclusion to science education, it suggests that edu-cators who use socioscientific curricula, particularly materials related to genetic engineer-ing, need to maintain a critical awareness of their students’ content knowledge. Educatorsshould use their students’ knowledge, relevant to socioscientific issues, to help determinethe appropriateness of issues incorporated into instruction.

The finding that some participants cited their own lack of knowledge regarding geneticsas a factor contributing to their inability to discuss genetic engineering issues is consistentwith other studies of SSI. Both Pedretti (1999) and Sadler and Zeidler (2004) documentthis phenomenon in other sampled populations. These results present important implica-tions for science classrooms with respect to conceptual change. Conceptual change theory(Posner et al., 1982) posits learner dissatisfaction with his/her current concepts or state ofknowledge as the first step toward meaningful learning. The discussion of socioscientificissues stimulated dissatisfaction with current levels of genetics understanding among manyparticipants. This result suggests that educators could use socioscientific issues as a wayof motivating students to engage in meaningful learning regarding science concepts whichunderlie these issues.

This study produced no evidence to suggest that individuals with differential levels ofcontent knowledge relied on different modes of informal reasoning (rationalistic, emotive,and intuitive). A person’s understanding of genetics concepts did not seem to make a dif-ference in terms of his/her use of rationalistic, emotive, and intuitive patterns of informalreasoning. This finding suggests that the instruction of content knowledge will not likelylead to changes in general informal reasoning patterns, a result which strengthens a claimwe have made in previous work (Sadler & Zeidler, in review) that students require oppor-tunities to express multiple modes of reasoning when dealing with socioscientific issues.Understanding the science behind a controversial issue does not necessarily imply that anindividual will base his/her decisions on that science content. Individuals with relativelyhigh content knowledge were every bit as likely to relate to SSI from affective perspec-tives as their peers with less content knowledge. Furthermore, we as educators have no


empirical basis for the belief that negotiating SSI from a rationalistic perspective results inhigher quality reasoning (at least defined in terms of the criteria outlined in this study) thanemotive or intuitive perspectives.

IMPLICATIONS FOR FUTURE RESEARCH

The findings of this project direct attention to several areas worthy of additional study.We defined the subsamples using a maximum variation sampling strategy (Lincoln & Guba,1985) to maximize the possibility of detecting relationships between informal reasoningand content knowledge. Because these results suggest that content knowledge was relatedto informal reasoning quality, future investigations with less dramatic differences in con-tent knowledge, such as those which might be present in a typical classroom, would beuseful.

Table 3 presents some demographic information for the participants, but these data areonly used to describe the sample. We did not attempt to control or assess the influence ofany of these variables. Potentially fruitful research projects could address how factors suchas race, religious affiliations, or epistemic orientations contribute to informal reasoningregarding SSI.

Several authors have suggested that socioscientific issues can be used as a vehicle forteaching important science content (Cajas, 1999; Pedretti, 1999; Zeidler et al., 2002), andthe results of this study indicate that understanding content knowledge is associated withhigher quality informal reasoning. These points lead to an important practical question:how can learning goals, both the development of content knowledge and informal reasoningskills, be maximized when using socioscientific curricula? Are these goals maximized whensocioscientific issues are introduced to students after the acquisition of related concepts orwhen the introduction of socioscientific issues and related concepts occur concurrently?Studies designed to address these questions would be useful for teachers and curriculumdesigners.

Finally, results concerning the relationship between content knowledge and informalreasoning quality highlight the need for information regarding the developmental appro-priateness of different socioscientific issues for students of varying ages. No materials,other than isolated studies conducted with a particular age group (like this study), explicitlydesigned to help educators select appropriate issues for their students currently exist. Re-search efforts to determine the developmental appropriateness of multiple socioscientificissues would be useful.

APPENDIX: INTERVIEW READING PROMPTS

Scenario 1: Huntington’s Disease Gene Therapy

Huntington’s disease (HD) is a neurological disorder caused by a single gene. Its symp-toms usually start between the ages of 35 and 45. The first symptoms include uncontrollablebody spasms and cognitive impairment. As the disease progresses, patients become physi-cally incapacitated, suffer from emotional instability, and eventually lose mental faculties.HD usually runs its course over a period of 15–20 years and always results in death. Noconventional treatments are known to work against HD.

Because Huntington’s disease is controlled by one gene, it could be a candidate for genetherapy. Should gene therapy be used to eliminate HD from sex cells (egg cells or spermcells) that will be used to create new human offspring?


Scenario 2: Nearsightedness Gene Therapy

Nearsightedness is a condition that affects millions of people world-wide. Nearsight-edness, also known as myopia, manifests in blurred distance vision. Interventions suchas eyeglasses, contacts, and corrective surgeries are frequently used to treat thiscondition.

If science found a single gene that produced nearsightedness, should gene therapy beused to eliminate that gene from sex cells (egg cells or sperm cells) that will be used tocreate human offspring?

Scenario 3: Intelligence Gene Therapy

We know that a person’s intelligence is controlled by a variety of factors includingboth environmental and genetic influences. It is likely that several genes contribute to aperson’s intelligence. No single factor, whether genetic or environmental, could completelydetermine an individual’s intelligence; however, it is conceivable that scientists could finda single gene that at least contributed to an individual’s intelligence.

If science were able to isolate a gene that significantly contributed to a person’s intelli-gence, should that gene be used for gene therapy to increase the intelligence of potentialoffspring?

Scenario 4: Reproductive Cloning Prompt

Many otherwise healthy couples are unable to bear children. Modern reproductive tech-nologies like fertility drugs and in-vitro fertilization have enabled some of these individualsto have their own children. However, some couples remain infertile and unable to have ababy. For these individuals, cloning could be used as another reproductive technology. Inthis case, one of the parents would serve as the genetic donor. The donor’s genetic materialwould be inserted into an egg cell, and then the embryo (the egg carrying a complete setof the donor’s genetic material) would be implanted into the woman. The embryo woulddevelop into a fetus and eventually be born as a baby.

Should individuals who want to carry and have their own children be able to choosecloning as a reproductive option?

Scenario 5: Deceased Child Cloning

A couple and their newborn child (their only child) are involved in a terrible automobileaccident. The father dies at the scene of the accident, and the baby is severely injured. Themother sustains only minor cuts and bruises. At the hospital, doctors inform the mother thather baby will undoubtedly die within a matter of days.

The woman wants to raise a child that is the product of her now deceased husband andherself. She would like to take cell samples from her dying child so that she can carry andgive birth to a genetic clone of the child. Should this woman be able to produce a clone ofher dying baby?

Scenario 6: Therapeutic Cloning

Thus far, you have read about and discussed reproductive cloning. Although the tech-nology and initial procedures involved in therapeutic and reproductive cloning are similar,the end-products and applications are different. In therapeutic cloning, a cloned embryo


is created and stimulated so that it begins growing. (Just like reproductive cloning, thisinvolves inserting the genetic material of a donor into an egg cell so that the resulting em-bryo is genetically identical to the donor.) The embryo would continue to develop until ithas formed stem cells. (This ordinarily occurs within three weeks of the time the embryostarts growing). At this point, the stem cells would be removed from the embryo. Stemcells are unique because they can be stimulated to develop into many different types ofbody tissues. For example, they can produce kidney tissue that could be transplanted intoindividuals with kidney disease or nerve cells that could be used for individuals sufferingfrom spinal cord injuries or Parkinson’s disease.

Two major problems are associated with organ transplantation: a lack of available or-gans, and immunological rejection. There are far more patients waiting for transplants thanthere are donated organs. In addition, the immune systems of patients who actually receivetransplants often reject the transplanted organ because the body recognizes it as a foreignsubstance. Organs and tissues produced by means of therapeutic cloning would solve bothof these problems. Patients awaiting transplants could donate their own genetic materialfor the production of the cloned embryo. Because the resulting tissue or organ would carrythe same genetic material as the patient, the immune system would not reject it. Shouldtherapeutic cloning be used to develop tissues for patients who need transplants such asindividuals suffering from fatal kidney disease?

REFERENCES

American Association for the Advancement of Science. (1990). Science for all Americans. New York: OxfordUniversity Press.

Andrew, J., & Robottom, I. (2001). Science and ethics: Some issues for education. Science Education, 85,769–780.

Bingle, W. H., & Gaskell, P. J. (1994). Scientific literacy for decisionmaking and the social construction of scientificknowledge. Science Education, 78, 185–201.

Cajas, F. (1999). Public understanding of science: Using technology to enhance school science in everyday life.International Journal of Science Education, 21, 765–773.

Campbell, N. A., Mitchell, L. G., & Reece, J. B. (1997). Biology: Concepts and connections (2nd ed.). MenloPark, CA: Benjamin/Cummings Publishing.

Copland, P. (2003). Science and ethics must not be separated. Nature, 425, 121.Council of Ministers of Education Canada Pan-Canadian Science Project. (1997). Common framework of science

learning outcomes: K-12. Retrieved June 2, 2003, from http://www.qscc.qld.edu.au/ kla.sose.publications.html.Dawson, V., & Schibeci, R. (2003). Western Australian school students’ understanding of biotechnology. Interna-

tional Journal of Science Education, 25, 57–69.Driver, R., Newton, P., & Osborne, J. (2000). Establishing the norms of scientific argumentation in classrooms.

Science Education, 84, 287–312.Eisenberg, N. (2000). Emotion, regulation and moral development. Annual Review of Psychology, 51, 665–697.Fleming, R. (1986a). Adolescent reasoning in socio-scientific issues, part I: Social cognition. Journal of Research

in Science Teaching, 23, 677–687.Fleming, R. (1986b). Adolescent reasoning in socio-scientific issues, part II: Nonsocial cognition. Journal of

Research in Science Teaching, 23, 689–698.Gardner, E. J., Simmons, M. J., & Snustad, D. P. (1991). Principles of genetics (8th ed.). New York: Wiley.Haskell, R. E. (2001). Transfer of learning: Cognition, instruction, and reasoning. San Diego: Academic Press.Hoffman, M. L. (2000). Empathy and moral development: Implications for caring and justice. Cambridge:

Cambridge University Press.Hogan, K. (2002). Small groups’ ecological reasoning while making an environmental management decision.

Journal of Research in Science Teaching, 39, 341–368.Jimenez-Aleixandre, M. P., Rodrıguez, A. B., & Duschl, R. A. (2000). “Doing the lesson” or “doing science”:

Argument in high school genetics. Science Education, 84, 757–792.Klug, W. S., & Cummings, M. R. (1997). Concepts of genetics (5th ed.). Upper Saddle River, NJ: Prentice Hall.Kolstø, S. D. (2001a). Scientific literacy for citizenship: Tools for dealing with the science dimension of

controversial socioscientific issues. Science Education, 85, 291–310.


Kolstø, S. D. (2001b). ‘To trust or not to trust,...’—pupils’ ways of judging information encountered in a socio-scientific issue. International Journal of Science Education, 23, 877–901.

Kuhn, D. (1991). The skills of argument. Cambridge: Cambridge University Press.Leighton, J. P., & Bisanz, G. L. (2003). Children’s and adults’ knowledge and models of reasoning about the ozone

layer and its depletion. International Journal of Science Education, 25, 117–139.Lincoln, Y. S., & Guba, E. G. (1985). Naturalistic inquiry. Newbury Park, CA: Sage Publications.Martinez-Gracia, M. V., Gil-Quilez, M. J., & Osada, J. (2003). Genetic engineering: A matter that requires further

refinement in Spanish secondary school textbooks. International Journal of Science Education, 25, 1147–1168.Means, M. L., & Voss, J. F. (1996). Who reasons well? Two studies of informal reasoning among children of

different grade, ability, and knowledge levels. Cognition and Instruction, 14, 139–178.Mehrens, W. A., & Lehmann, I. J. (1991). Measurement and evaluation in education and psychology. Fort Worth,

TX: Holt, Rinehart, and Winston.Millar, R., & Osborne, J. (Eds.). (1998). Beyond 2000: Science education for the future. London: King’s College

School of Education.Miller, K. R., & Levine, J. (1998). Biology (4th ed.). Englewood Cliffs, NJ: Prentice Hall.National Research Council. (1996). National science education standards. Washington: National Academy Press.Osterlind, S. J. (1989). Constructing test items. Boston: Kluwer.Patronis, T., Potari, D., & Spiliotopoulou, V. (1999). Students’ argumentation in decision-making on a socio-

scientific issue: Implications for teaching. International Journal of Science Education, 21, 745–754.Pedretti, E. (1999). Decision making and STS education: Exploring scientific knowledge and social responsibi-

lity in schools and science centers through an issues-based approach. School Science and Mathematics, 99,174–181.

Perkins, D. N., Farady, M., & Bushey, B. (1991). Everyday reasoning and the roots of intelligence. In J. F. Voss,D. N. Perkins, & J. W. Segal (Eds.), Informal reasoning and education (pp. 83–105). Hillsdale, NJ: Erlbaum.

Posner, G. J., Strike, K. A., Hewson, P. W., & Gertzog, W. A. (1982). Accomodation of a scientific conception:Toward a theory of conceptual change. Science Education, 66, 211–227.

Queensland School Curriculum Council. (2001). Studies of society and environment. Retrieved June 2, 2003, fromhttp://www.cmec.ca/science/framework/index.htm.

Sadler, T. D. (2004a). Informal reasoning regarding socioscientific issues: A critical review of the literature. Journalof Research in Science Teaching, 41, 513–536.

Sadler, T. D. (2004b). Moral and ethical dimensions of socioscientific decision-making as integral components ofscientific literacy. The Science Educator, 13, 39–48.

Sadler, T. D., & Zeidler, D. L. (2004). The morality of socioscientific issues: Construal and resolution of geneticengineering dilemmas. Science Education, 88, 4–27.

Sadler, T. D., & Zeidler, D. L. (in review). Patterns of informal reasoning in the context of socioscientific decision-making. Journal of Research in Science Teaching.

Siebert, E. D., & McIntosh, W. J. (Eds.). (2001). College pathways to the science education standards. Arlington,VA: NSTA Press.

Solomon, J. (1994). Knowledge, values and the public choice of science knowledge. In J. Solomon & G. Aikenhead(Eds.), STS education: International perspectives on reform (pp. 99–110). New York: Teachers College Press.

Toulmin, S. (1958). The uses of argument. Cambridge: Cambridge University Press.Tytler, R., Duggan, S., & Gott, R. (2001). Dimensions of evidence, the public understanding of science and science

education. International Journal of Science Education, 23, 815–832.van Eemeren, F. H., Grootendorst, R., Henkemans, F. S., Blair, J. A., Johnson, R. H., Krabbe, E. C. W., Plantin,

C., Walton, D. N., Willard, C. A., Woods, J., & Zarefsky, D. (1996). Fundamentals of argumentation theory: Ahandbook of historical backgrounds and contemporary developments. Mahwah, NJ: Erlbaum.

Yang, F. Y., & Anderson, O. R. (2003). Senior high school students’ preference and reasoning modes about nuclearenergy use. International Journal of Science Education, 25, 221–244.

Zeidler, D. L. (1984). Moral issues and social policy in science education: Closing the literacy gap. ScienceEducation, 68, 411–419.

Zeidler, D. L., & Keefer, M. (2003). The role of moral reasoning and the status of socioscientific issues in scienceeducation: Philosophical, psychological and pedagogical considerations. In D. L. Zeidler (Ed.), The role ofmoral reasoning and discourse on socioscientific issues in science education. Netherlands: Kluwer.

Zeidler, D. L., & Schafer, L. E. (1984). Identifying mediating factors of moral reasoning in science education.Journal of Research in Science Teaching, 21, 1–15.

Zeidler, D. L., Walker, K. A., Ackett, W. A., & Simmons, M. L. (2002). Tangled up in views: Beliefs in the natureof science and responses to socioscientific dilemmas. Science Education, 86, 343–367.

Zohar, A., & Nemet, F. (2002). Fostering students’ knowledge and argumentation skills through dilemmas inhuman genetics. Journal of Research in Science Teaching,39, 35–62.

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The significance of content knowledge for informal reasoning regarding socioscientific issues: Applying genetics knowledge to genetic engineering issues