Toward the Teaching of Modern Biology in High School

W. C. Van DeventerWestern Michigan University^ Kalamazoo, Michigan 49001

The Biological Sciences Curriculum Study (BSCS) is now morethan a decade old. More than half of this time has passed since itsmaterials became commercial and consequently available for generaluse. At this point it is possible to assess the effects of it on the teach-ing of modern biology in high school.BSCS has been part of a rather large family of ^alphabetic^ cur-

riculum studies, generally supported, at least in part, by federal orfoundation funds, written by committees rather than by one or afew individuals, and tried out extensively in classroom situationsbefore being published commercially.1 It is safe to say at this timethat, although not all of the national curriculum studies have beenequally successful, all of them have had a marked and probablylasting effect on the teaching of their respective subject matter disci-plines. It is safe to say also that BSCS has been one of the mostsuccessful of them.

CHANGES IN TEXTBOOKS AND LABORATORY GUIDESIt should be remembered in making any assessment of the value

and effects of the curriculum studies that it was not their initialpurpose alone to produce textbooks and other teaching materialsthat would replace commercially produced ones. It was even moretheir purpose, on a long range basis, to stimulate writers and pub-lishers of commercial texts and laboratory guides to update theirmaterials, and the methods of teaching and testing that went withthem. It was intended that this would be accomplished through thepressure of competition. This has happened to a large extent in thecase of all of the subject matter areas in which the alphabetic studieswere conducted. It has certainly been true in biology.Even a casual comparison of popular high school biology textbooks

of fifteen years ago with the most recent editions will show that theinclusion and treatment of the results of research during the period ofthe "knowledge explosion" since World War II has both increasedand been updated. Commercially produced high school textbooksand laboratory guides, published even as late as 1963 (the date ofpublication of the first commercial editions of BSCS), "dragged theirfeet" in including the results of recent research, in the use of an ex-perimental approach in the laboratory, and in the use of living ma-

1 Sixth Report of the International Clearinghouse on Science and Mathematics Curricular Developments. J. DavidLockard, ed., AAAS Commission on Science Education and Science Teaching Center, University of Maryland,College Park, Maryland, 1968.

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terial. Since the BSCS materials presented a radical departure fromconventional high school biology in terms of all of these, the ap-pearance and widespread use of BSCS must be given major credit forthe changes which have taken place since the time of its publication.

It is now possible to arrange the most recent editions of currentlyavailable non-BSCS commercial texts on a "gradient of modernity/7based on the extent to which they include modern materials dealingwith cellular physiology, biochemical genetics, and ecosystem ecology.All of these texts have been updated to some extent, and some ofthem now compare quite favorably with the BSCS texts in theseareas. Most of them also retain the conventional taxonomic andsystemic physiology material to a greater or less extent. This isstill in demand in much of the high school market, and its retention,along with the more modern material undoubtedly constitutes anattempt to "ride both horses.55

Unfortunately, the laboratory guides which accompany these textsshow generally less change. If they are arranged on a correspondinggradient on the basis of the open-endedness of the laboratory ex-periences which they contain, which has been the outstanding featureof the BSCS laboratory guides, they are seen to retain much conven-tional conservatism. They still rely heavily on "show and tell" lab-oratory exercises and the filling in of blanks for answers. They have,however, made some progress in the use of living rather than pre-served materials, and in breaking free from the earlier emphasis ondissection and drawings which characterized the classic biology lab-oratory experiences of a generation ago.The writer has recently used this "gradient" approach on several

occasions in discussing currently available biology textbooks andlaboratory guides with groups of high school teachers and textbookselection committees. This approach furnishes a valuable criterionwhich could be applied equally well to actual teaching in the class-room-laboratory.

CHANGES IN STANDARDIZED TESTS

Another area in which changes have occurred has been in the formand content of standardized evaluation materials. The use of prob-lem-type, "best-answer" test items, as contrasted to factually-ori-ented, "right-wrong" test items, has been one of the characteristicsof most of the alphabetic curriculum studies. It is one of the featureswhich has distinguished them from the older, conventional courses.2

2 Van Deventer, W. C. "Toward a ’Comparative Anatomy’ of the Curriculum Studies." Science Education50: 196-203, April, 1966. Other characteristics which most of the curriculum studies have had in commonare (1) stress on recently discovered scientific knowledge, (2) organization of subject matter around concepts orideas rather than survey of a field, (3) open-ended or problem-solving laboratory experiences, and (4) emphasison the process of inquiry, variously defined.

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Although test items of best-answer type were invented before 1950,and were in use in certain kinds of tests, they were not widely used forevaluation of student achievement in specific science courses. TheBSCS tests prepared for use with the three Color Versions, however,have generally used this type of item.3 These tests are directed towardan understanding of the ^nine themes554 on which the BSCS programis based, rather than involving primarily factual recall.

Students and teachers have raised objections to the use of thistype of test for evaluation of individual achievement in a course. Theitems are keyed to match the collective opinion of the consensus of anexperimental group, generally quite large, of test makers and stu-dents, edited and modified on the basis of a series of item analyses.By contrast, test items of the conventional sort are either right orwrong in an objective sense. Both students and teachers are moresecure with a test consisting of conventional right-wrong items. Onthe other hand there is reason to believe that best-answer items de-mand more of students in the way of thinking, analysis of data,application of knowledge to new situations, and problem-solving.Recently the writer has had an opportunity to review a nearly com-plete set of the New York Regents Examinations in Biology5’6 cover-ing the period from 1950 to 1968. Since this time span includes theperiod during which BSCS was developed and became widely adop-ted, the experience proved particularly interesting. Because of theway in which they are used, the Regents Examinations necessarilyreflect changes that have taken place in the teaching of biology in theclassroom. When they are looked at as part of a larger picture, in-cluding the changes which have occurred during the same period intextbooks and laboratory materials, they serve as a quasi-objectiveindicator of changes in the content, methodology, and philosophy ofteaching biology in high school.During the nineteen year period three kinds of changes were ap-

parent in the Regents Examinations:s Biological Sciences Curriculum Study, BSCS Green Version High School Biology Achievement Tests 1, 2, 3, 4,

Form P. Rand, McNalIy and Company, Chicago, Illinois, 1963.Biological Sciences Curriculum Study, Blue Version, Biological Science: Molecules to Man, Achievement Tests

1, 2, 3, 4, Form P. Houghton Mifflin Company, New York, 1963.Biological Sciences Curriculum Study, Yellow Version, Biological Sciences: An Inquiry info Life, Achievement

Tests 1, 2, 3, 4, Form R. Harcourt, Brace and World, Inc., New York, 1964.4 Schwab, Joseph J., Biology Teachers Handbook, BSCS, John Wiley and Sons, Inc., New York, 1963. The

nine BSCS themes are: (1) Change of living things through time: evolution, (2) Diversity of type and unity ofpattern in living things, (3) Genetic continuity of life, (4) Complementarity of organism and environment, (5)Biological roots of behavior, (6) Complementarity of structure and function, (7) Regulation and homeostasis:the maintenance of life in the face of change, (8) Science as inquiry, and (9) Intellectual history of biologicalconcepts.

s The University of the State of New York. Regents High School Examinations. Biology. 1950-1968.6 Copies of these examinations 1950-1967 were made available to the writer by Dr. George G. Mallinson,

Dean, School of Graduate Studies, Western Michigan University. A copy of one of the 1968 tests was contributedby Miss Helen Rice, Coordinator of Curriculum Planning, West Irondequoit Central School District, Rochester,New York.

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1. From the beginning of the period the examinations tended to introducebiological or general science topics that were prominent in the news, andwere therefore available to the general reader.

2. The examinations showed a marked increase in the number of items basedon physiology (general and cellular), biochemically-related biology, andecology, and an equally marked decrease in items based on taxonomy,anatomy, and mammalian or systemic physiology.

3. The examinations came to include more "problem situation55 and "best-answer" items, and fewer items based on simple factual recall.

Each of these changes may be looked at in greater detail:1. The influence of science-in-the-news was not current. A topic had to be in

the news for a considerable period before any item concerning it appeared inthe examinations. This time lag was generally five to ten years. Usually,once a topic of current interest was introduced, however, it continued toappear thereafter, sometimes with increasing frequency. Examples oftopics, with dates of their first appearance in the tests, are:a. Radioactive isotopes 1950b. Sulfa drugs and antibiotics 1951c. Chemical insecticides 1954d. Polio vaccine 1957e. Carbon 14 dating 1957f. Radioactive fallout 1959g. Space ship life support systems 1962h. Role of nucleic acids in genetics 1963i. Gene pool concept in evolution 1968

2. The increase in the proportion of items based on the areas of "modernbiology^ (general and cellular physiology, biochemically-related biology,and ecology) first appeared in 1959. Once this change had occurred, how-ever, it proceeded rapidly. By 1966 the tests were almost completely"modern" in their content. In general, they also indicated greater sophis-tication in the use of laboratory equipment, showing that they assumed thecarrying on of laboratory work involving experimentation, in the place ofconventional dissection, observation, and description. They also exhibitedgreater sophistication in terms of sampling more widely the areas within thebroad field of biology.

3. The use of best-answer items in the examinations began in 1960. A fewproblem-situation items had appeared in 1959. These, however, were notspecifically of best-answer type. Since the categorization of test items asbest-answer rather than right-wrong is necessarily somewhat subjective, twoblocks of successive items of each type, one from an early test and theother from a later one, classified as right-wrong and best-answer respectivelyin the judgment of the writer, are quoted here by way of illustration:

^RIGHT-WRONG ITEMS"

(from the 1950 test)"17. A young organism developing within the body of the mother is called a(an)

(1) embryo (2) seed (3) sperm (4) egg18. Essential organs of common flowers include (1) anthers (2) bulbs (3)

placentas (4) rhizomes19. Every cell contains (1) cell membrane and cytoplasm (2) cell wall and

cytoplasm (3) nucleus and chloroplasts (4) plastics and vacuoles20. The cells that can easily be scraped from the lining of the mouth make up

(1) connective tissue (2) epithelial tissue (3) supporting tissue (4) volun-tary tissue

21. Thiamine is a(an) (1) enzyme (2) hormone (3) tissue (4) vitamin^

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"BEST-ANSWER ITEMS57

(from one of the 1967 tests)^Directions (86-90): Write the number of the word or expression that bestcompletes the statement or answers the question. Base you answers on thedemonstration described below and your knowledge of biology.A student floated a lighted candle on a cork in a shallow pan of water.

He inverted a bottle over the burning candle. He measured the time re-quired for the candle to stop burning. He then removed the bottle, relit thecandle, filled the bottle with exhaled air, and again inverted it over thecandle. When the candle went out, he repeated this second part of hisdemonstration, but before filling the bottle with exhaled air, he ran 100yards at top speed.

86. The probable purpose of this demonstration was to show that(1) inhaled and exhaled air differ in composition(2) exhaled air contains less carbon dioxide than inhaled air(3) combustion releases heat and carbon dioxide(4) respiration produces heat

87. One observation which the student would make is that the candle went out(1) most quickly in the first trial(2) most quickly in the last trial(3) at the same time in all three trials(4) only in the first trial

88. A second observation which the student would make is that(1) atmosphere exerts pressure(2) atmosphere contains oxygen(3) water rose inside the bottle(4) inhaled air contains carbon dioxide

89. As a result of the demonstration the student might be justified in conclud-ing that exhaled air(1) contains carbon dioxide(2) contains no oxygen(3) has less carbon dioxide than inhaled air(4) has less oxygen than inhaled air

90. As a result of this demonstration, the student might also be justified inconcluding that(1) activity results in a higher percentage of oxygen in exhaled air(2) activity results in a higher percentage of carbon dioxide in exhaled air(3) respiration is similar to burning(4) respiration produces more carbon dioxide than burning"

Of course the distinction between right-wrong and best-answer testitems is not as clear in all cases as it is in the ones quoted here forpurposes of illustration. In the judgment of the writer, however,there were only four best-answer items in the 1960 tests. Eight ap-peared in 1961. More than half of the items in the 1962 tests were ofthis general type. In the tests for 1963 and following nearly all of theitems, except for a few placed at the beginning of each test for pur-poses of introduction, could be considered in this category.By way of conclusion, from this analysis of the trends in develop-

ment of the New York Regents Examinations in Biology over anineteen year period, it appears that the more recent ones are in noway inferior structurally, in terms of content, or in terms of open-

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endedness, to the BSCS tests. They do, of course, lack the relation-ship to specific "themes" characteristic of the BSCS tests. The mostrecent Regents Examinations represent an almost complete reversalof structure, content and open-endedness from those of the earlyfifties. This change has, in general, taken place during the period from1960 through 1967. This period also saw the development, com-mercial publication, and widespread use of the BSCS materials.

SUMMARYThe Biological Sciences Curriculum Study (BSCS) was started in

1958. The materials produced by it (textbooks, laboratory guides,and tests in three Color Versions), after being widely disseminatedand tested in classrooms in experimental versions, were first publishedcommercially in 1963. Although they have been extensively adoptedin competition with commercially written and produced biologytexts and laboratory manuals, an even more important functionwhich they have served is to stimulate the modernization and up-dating of course materials produced by commercial writers and pub-lishers. A comparison of the most recent examples of such commercialtexts and laboratory guides with earlier examples shows the extent towhich this function has been accomplished.

Another, and quasi-objective indication of the BSCS influence canbe seen in an analysis of standardized biology tests over a period ofapproximately twenty years. The writer has had the privilege ofmaking such an analysis of the New York Regents Examinations inBiology 1950-1968. Although these examinations always reflectedcurrent science developments in a conservative fashion, after a lag offive to ten years, a radical change in their structure and content setin about 1960. As a result of this, they now reflect the broad aspectsof "modern biology,n include the knowledge gained through recentresearch, and consist largely of open-ended, best-answer items inwhich the student is required to exercise thoughtful judgment andapply knowledge to new situations rather than simply recall facts.

ANNUAL AAAS CONVENTIONBOSTON, MASSACHUSETTS

DECEMBER 1969