Research in Science Education, 1994, 24, 280-286

DATA HANDLING IN THE PRIMARY CLASSROOM: CHILDREN'S PERCEPTION OF THE PURPOSE OF GRAPHS

Susan Rodrigues University of Durham

ABSTRACT

The National Curriculum programme of study for Science 1 in England and Wales states that pupils should be encouraged to develop investigative skills and understanding of science through activities which "promote the search for patterns in data and the ability to make simple predictions based on findings" (Department of Education and Science, 1991, p. 14). In order'to search for patterns children have to first understand the purpose of graphs and the relationship of variables. This paper describes some of the preliminary findings of the Data Handling in Primary Science Project. The majority of primary school children, involved in a data handling project (Rodrigues, 1994), see graphs in science as an end product to be displayed. In addition the children appeared to have a very limited understanding for the type of graph employed being determined by the variable involved. Furthermore whilst some of the children were able to read information from a graph, the language used had a marked effect on cueing the response.

INTRODUCTION

The aim of this paper is two-fold:

to add support to the notion that children of primary school age appear to understand the idea of fair testing; they know what to change, what to keep the same and what to measure, and they can employ commendable graphing skills. to indicate that children of primary school age do not fully understand the relationship between the variables and consequently the type of graph needed to be drawn, and are therefore unable to appreciate fully the data their investigation has generated.

Data handlin.q and the National Curriculum for Science in En.qland and Wales

The National Curriculum for Science in England and Wales (Department of Education and Science, 1991) contains four statutory attainment targets, one of which is concerned with scientific investigations. Underpinning these science investigations are fundamental characteristics of procedural understanding which have been termed 'concepts of evidence' (Duggan & Gott, 1994). One of these concepts of evidence is the concept of data handling. This involves understanding that there is a link between graph representation and the type of variable that they represent and understanding that tables and graphs can provide patterns that explain the behaviour of variables (Duggan & Gott, 1994).

The National Curriculum for Science in England and Wales (Department of Education and Science, 1991) demands that at each Key stage, children should attempt to discern relationships or patterns in their investigation findings (Austin, Holding, Bell & Daniels, 1989). Indeed, the School Curriculum and Assessment Authority (1994) states that at Key stage 2, children (aged 7 -11), should be encouraged to search for' patterns in data, and.to interpret

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the data against the demands of the problem. This implies that children have to design investigations that require a systematic approach involving simple variables in a fair test. Within the fair test approach the establishment of causal links between the variables is considered an important scientific skill because independent and dependent variables define a scientific investigation.

If patterns are to be identified, so that the investigation can be evaluated and communicated by the child, then the type of graph used is important. This in turn is dependent upon the variables in the investigation. The character of the data and the form in which they are handled by children is an important consideration, if the data are to be scanned for possible underlying 'causes' of perceived behaviour.

If the investigation lends itself to the construction of line graphs because the variables are continuous, but the child constructs a bar graph, because it is easier to do so, then the value of the data collected is restricted. Consequently the information construed from the data will be limited and interpretation becomes problematic.

Foulds, Gott and Feasey (1992) stated that, unlike the notion of a fair test, presenting and interpreting findings does not appear to have been established primary classroom science practice. Children report and record their findings in an everyday way rather than use tables and graphs. For example, a recent report (Foulds, Gott & Feasey, 1992) indicated that 91% of year five children report their investigations sequentially and 2% included a critical evaluation. Children need to understand why they are gathering and presenting data, but many children lacked this understanding. Indeed, Phipps (1994) suggested that at Key stage 1 many children are not given the opportunity to explore the process or purpose of handling data. Furthermore Foulds, Gott and Feasey (1992) also stated that at Key stage 2, 1.86% of the children drew line graphs and 12.6% drew bar graphs, regardless of whether this was the best way to present the data.

The Assessment of Performance Unit findings (Department of Education and Science, 1988, 1989) indicated that the form of presentation of variables could affect the child's performance in interpreting the information. Therefore it is important that children understand the value of graphing skills both in terms of assessing their performance and in terms of developing scientific process skills. Using line graphs to explore the existence of relationships between variables is an important skill that children are required to develop in primary school science (Austin, Holding, Bell & Daniels, 1989; Phipps, 1994; School Curriculum and Assessment Authority, 1994).

The 'picture' presented by a line graph has the potential to enhance children's interpretation of their investigation findings. Properly interpreted graphs enable relationships that were hidden or less obvious in the results table to become more obvious and open to inspection. Austin, Holding, Bell and Daniels (1989) indicated that a sizeable proportion (30%) of twelve year old children made no useful sense of either the graphs or the data available to them. These children may have no idea how graphs can help uncover a relationship between variables. This may be due to the fact that customarily children are taught and expected to practice the low level mechanics of plotting particular graphs when given a table of information (Jackson, Edwards & Berger, 1993). In primary school science lessons there is little time available to focus on issues of interpretation and evaluation for purposes of modification and extension of their investigation. If the data acquired during an investigation are not transformed into communicable information from which trends and patterns can be ascertained, then the graph has limited value and the children may as well continue to report their data in the form of prose.

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THE DATA HANDLING IN PRIMARY SCIENCE PROJECT

The Data Handling in Primary Science Project involved 22 schools in the North East of England. The project was initiated to develop primary science curriculum support material for scientific investigations, in particular, data handling, directly linked to the National Curriculum (Rodrigues, 1994). The main sample in this project consisted of one class of nine special- needs school-children (aged 9-16), one class of 23 Year 3 (aged 7-8) children and" 355 Year 5 children (aged 9-10).

The pre-questionnaire, the main source of data in this paper, was completed by 378 children; they were given a questionnaire to complete 3 to 6 weeks before the resource material was tested. It contained three main sections. The first investigated children's knowledge of plastics because the research was partly sponsored by I.C.I. and the resource materials involved plastics. The second section investigated children's abilities to construct, interpret and evaluate graphs and tables. The third section sought children's understandings for why school children and scientists used graphs and tables. The questionnaire codes represent the area, the school, the child, the age of the child and the gender of the child. Information in this paper was also derived from interviews with four children. The teacher was asked for an able student, two average students and one below average student. These children worked with the researcher on investigations described in the resource material (Gray, Rodrigues, Simpson & Sowden, 1994). The children (aged nine, two boys and two girls) were withdrawn from lessons for approximately an hour over a period of four weeks. During this time the children undertook two activities from the resource which required bar and line graphs to be drawn. Two weeks after the final lesson, the children were separately and informally asked about the line graphs they had drawn during the sessions. The researcher asked them to explain how and why they constructed the graph and to interpret the graph.

FINDINGS

Preliminary findings from the project indicate that the low level mechanics of graph construction and presentation is the main focus of data handling activity in the primary science classroom. Generally the questionnaires indicated that children's overall performance in constructing bar graphs is better than their performance relating to line graphs. Yet, the School Curriculum and Assessment Authority (1994) suggests that teachers and students will need to focus on both types of graphs in science. They stated that children should be taught "to use tables, bar charts and line graphs to present results...to use results to draw conclusions ... to say whether the evidence collected supports any prediction made" (p. 8). However, this aspect is not the focus of the findings. Instead we consider the children's rationale and understanding for using particular types of graphs in science.

An experiment was described in the questionnaire in terms of two fictitious children wanting to find out how fast a cup of tea cooled down. The fictitious children explained that they placed tea in a plastic cup and measured the temperature of the tea every two minutes. They then presented their results; one opted for bar graphs and one for line graphs. The children completing the questionnaire were then asked to identify which type of graph they would draw if they conducted a cooling tea experiment. Their responses are summarised in Table 1.

The children were asked to justify their responses and their justifications were also categorised (Table 2). These categories were predetermined but added to when and if a child's response did not comply with any of the categories. The categories were determined originally by the researcher and three teachers checked the categories and responses. (Please note the children's words are represented as written by themselves, with no corrections for grammar or spelling.)

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TABLE 1 TYPES OF GRAPHS CHILDREN WOULD DRAW FOR A COOLING TEA INVESTIGATION.

Category Percentage of children (n =378)

No response 8% ' Line graph 16% Bar graph 52%

Both grapl~s 24%

TABLE 2

CHILDREN'S JUSTIFICATION FOR THEIR CHOICE OF GRAPH

Category Percentage of children (n =378)

Examples to illustrate the categories.

No response 15% Blank space or child wrote 'do not know.' 0% Continuous variable

Aesthetic/affective Ambiguous

20% Because it looks betur. (T16/19/8g) 12% I just gessed because she is meafing

(N18/21/9g) 45% Because it is easyer to do. (N18/17/9b) 8%

Easy to do Same information Because I think there both the same.

(N12/5/9b)

The majority of children did not perceive the variable under consideration to be continuous and consequently did not select a graph that best suited this type of data. In another question, children were given the same information, involving continuous variables, in the form of a line graph and a bar graph. They were asked to read data off a point located at the intersection of two labelled scale divisions (i.e. a value that required them to use both scales but was on a main division, e.g. what was the temperature of the water after 30 minutes?). Less than 8% used a line graph. The majority used a variety of strategies involving the bar graph to provide a sensible response.

If children do not consider the importance and the distinction between the variables, then they are unlikely to bring the variables together in causal statements. This means that they are unlikely to 'describe' the relationship between variables although they might well be able to read off the graph and provide numerical responses. Indeed interviews with the children indicated that they were able to read off points on the graph. The four children, interviewed were asked if they recalled drawing the graphs and asked to recount the occasion. The children could clearly recall drawing the line graph and were able to describe the activity which lead to them constructing the graph.

The four children were then asked to read data off a discrete point, (i.e. a value that could be read off a numbered point, for example what was the final temperature of the water in cup one?) They were asked to read data off a point located at the intersection of two labelled scale divisions. The children were also asked to read data off a poir~t located at the intersection of minor divisions, (i.e. a value that required them to use both scales but involved the sma}ler divisions on the sca~e, e.g. How long did it take before the water had cooled to

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27~ with the response being 10�89 minutes.) All the children were able to read and provide responses that were accurate given the graphs they had drawn.

The four children were also asked what was the temperature of the water at the start of the investigation. Three of the four children appeared to be concentrating very hard, then looked forlornly around the room, and stated that they could not remember. Later, but during the same interview, when the question was rephrased to "What was the temperature of the water at zero minutes?", all four children were able to respond correctly. This could indicate that the language and context in which the question is framed, clues the child into a response. In the questionnaire, children were also asked why scientists draw graphs. This was an attempt to probe whether children had an understanding of the purpose of graphs in science. Table 3 provides an overview of their responses. Once again, the illustrative examples of children's comments have not been amended for their spelling or grammar.

TABLE 3 CHILDREN'S UNDERSTANDINGS FOR WHY SCIENTISTS DRAW GRAPHS

Category

No response To show patterns

Percentage of children (n=378)

27% 1%

Examples to illustrate the categories.

Blank space or child wrote 'do not know.' So you can see how many people liked elephants and that sort of thing. (T1/14/10g)

Aesthetic reasons 0.5% Becase the like drawing. (N12/5/9b) Ambiguous 17% To c01ure what the have got of jigsaws so

they do not miss a peace. (T16/6/8g) Easy to do 13%

Easy to read/present information

Because it would save them writing everything and their easy to draw. (T14/15/9g) I think scientists draw graphs because it is a good way of recording your answers and it is quick and easy to read. (T14/22/10g)

DISCUSSION

If children are to meet the criteria set out by the National Curriculum in Science in England and Wales (Department of Education and Science, 1991; School Curriculum and Assessment Authority, 1994), they have to be able to present their data in suitable forms which aid their quest for patterns and trends. This in turn requires children to be able to select graphs appropriately and to be able to read information from graphs. Data handling requires not only the ability to read information from a graph but an understanding of the function and purpose of a graph, so as to inform the design and execution of science investigations.

The children interviewed were able to read scales that involved both major and minor grid lines. Questionnaire responses indicate that many children did not read the scales accurately and therefore could not provide a correct value. However, the reasons for this (inability to count, development of counting strategies which foster errors, 'sloppy' readings etc.) have not been determined. Neither the interviews not the questionnaires provided an indic.ation of the strategies children used to read these scales.

Children who completed the questionnaire appeared not to realise that variables determine the type of graph that best fosters interpretation of the collected data. In the sample, 45% of the

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children would choose to draw a line graph or a bar graph because it was easy for them to do. This may be due to children receiving more experience and practice of bar graphs in primary schools. This is problematic, because the review of the National Curriculum by the School Curriculum and Assessment Authority (1994) has led to statements proposing that children should be taught to use bar and line graphs, and determine whether the evidence they collected provided any support for the prediction they made.

The children in this project did not select the line graph because they were able to distinguish the variables as either continuous or discrete. Therefore the children may not understand the nature of continuous or discrete variables and do have an understanding of the particular variable for the 'cup of tea' experiment. This would imply that the children do not understand the value or purpose of bar or line graphs or indeed the relationship between variables.

Only 1% of the pre-questionnaire sample indicated that scientists use graphs to illustrate patterns or determine trends. Therefore whilst large numbers of children in this project were able to read data that corresponds to particular points on the graph, the vast majority perceive graphs as visual presentations of information. Even though the National Curriculum in Science in England and Wales (Department of Education and Science, 1991) has advocated the importance of data handling in science investigations, there appear to be many children who are still unaware or confused as to the purpose of graphs and tables in science. In the pre- questionnaire sample 42% of the children indicated that scientists draw graphs because they are easy to read or are useful in presenting information. Whilst displaying work is a commendable purpose, graphs are used in science to do more than present information. Graphs are used to help determine trends and patterns, to evaluate investigations and to identify relationships between variables.

If the graph chosen for an investigation is inappropriate, and takes no account of the type of variable, then the graph loses much of its power and the purpose is lost. The children in our sample, have obviously been taught the mechanics of drawing graphs but have yet to understand the value of these graphs in their science investigations. Children who do not identify relationships in their graphical data show a lack of awareness of the meaning of graph axes. In addition the purpose of a graph and data handling is limited to the ability to demonstrate the practical skill of constructing a graph and the mechanical ability to read minor and major grid marks.

CONCLUSION

If graphs and tables are taught simply as algorithms, then the ability to tease out explanations from the patterns and trends observed will be restricted. If the children do not understand the purpose of graphs then data handling will not impinge upon the design or the execution of the investigation. Furthermore, if the children acquire the skills of drawing graphs and tables mechanically they may learn the skill in isolation, perform the skill as an end in itself and not acquire an understanding of the scientific procedure. Teachers and children have to bridge the gap between performing mechanistic skills resulting in display work, and incorporating data handling as a vital component and procedure of a scientific investigation. From an assessment point of view it is important to note the impact of language, signalled in this paper, in prompting a response from the children. Minor changes in the use of language resulted in quite different perspectives of children's skill. Three of the children interviewed associated "temperature at the start of the investigation" with having to recall the figure from memory, whereas being asked about the temperature at zero minutes resulted in them using the graph. Therefore there are implications with regard to assessing children on their ability to perform particular graphing skills. The choice of question will have a crucial role for those who

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develop Standard Assessment Tasks. These issues need to be investigated much more vigorously and in more detail.

There is an assumption in science education that the process approach to school science will promote elements of scientific methodology, during which the child will practice skills such as hypothesising and interpreting data. From the school science point of view, this means encouraging children to design experiments to help them ascertain and" determine relationships, not simply teach them the mechanics of graph work. Teachers and the curriculum have to encourage the children to use their science knowledge to make sense of the data and to encourage the children to understand the need to draw different types of graphs depending on the variables being considered to best illustrate their data and hence interpret the resultant information.

REFERENCES

Austin, R., Holding, B., Bell, J., & Daniels, S. (1989). Assessment matters No. 7. Patterns and relationships in school science. London: SEAC.

Department of Education and Science (1988). Science at a.qe 11. A review of APU survey findin.qs 1980-84. London: HMSO.

Department of Education and Science (1989). Science at a.qe 13. A review of APU survey findings 1980-84. London: HMSO.

Department of Education and Science (1991). Science in the National curriculum (England and Wales). London: HMSO

Duggan, S., & Gott, R. (1994). Investi.qative work in the science curriculum. Milton Keynes: Open University Press.

Foulds, K., Gott, R., & Feasey, R. (1992). Investi.qative work in science- A report commissioned by the National Curriculum Council. University of Durham, School of Education.

Gray, C., Rodrigues, S.G.A., Simpson, L., & Sowden, C. (1994). Primary science; Data handlin.q activities: Usin.q qraphs, tables and sensors. School of Education, University of Durham.

Jackson, D. F., Edwards, B.J., & Berger, C. F. (1993). Teaching the design and interpretation of graphs through computer aided graphical data analysis. Journal of Research in Science Teachinq, 30(5), 483-501.

Phipps, R. (1994). Data handling in scientific investigations in the primary school; some findings and implications of a research project. Education 3-13, 22(2), 26-33

Rodrigues, S.G.A. (1994). Data handlin.q in primary science project. Workin.q paper 3. Exploration of Science Team, School of Education, University of Durham.

School Curriculum and Assessment Authority (1994, May). Science in the National Curriculum. Draft Proposals. London: HMSO.

AUTHOR

DR. SUSAN RODRIGUES, Lecturer, School of Education, University of Durham, Leazes Road, Durham, DH1 1TA England. Specializations: use of information technology in primary science, chemistry curriculum development.