TEACHING AND LEARNING THE PROCESSES OF
SCIENCE AND TECHNOLOGY
P. Murphy and R. McCormick
The seminar presented by Patricia Murphy and Robert McCormick was in two parts and they are each presented separately.
PART 1 : TEACHING AND LEARNING THE PROCESSES OF SCIENCE : MESSAGES FOR TECHNOLOGY EDUCATION? INTRODUCTION
Changes in the content and structure of the UK science curriculum reflect a long history of debate and controversy. Technology education as defined in the English and Welsh national curriculum has similarly, but more recently, undergone radical and controversial change. Some of the key debates about science education that emerged through the eighties and influenced curriculum development were the outcome of extensive research into students' learning and teachers' practice. Recent critiques (DONNELLY
and al, 1994 ; FOULDS and al, 1992) of the national curriculum definition of
science have indicated a need to extend even further the research base of science education to explore the nature of students' learning and their progression in procedural and conceptual understanding. There is no comparable body of research into learning and teaching in technology. The large scale research of the Assessment of Performance Unit in Design and Technology (KIMBELL and al, 1991) being an exception. Until recently
most other research in technology education has focused on curriculum development and has begun to focus on classroom practice in technology in terms of the tasks used, teachers' curriculum intentions and understandings and pupils' behaviours, and perceptions of their learning (MCCORMICK and
al, 1994 ; KIMBELL and al, 1994 ; DONNELLY and al, 1994). This research
has pointed to potential commonalties in the dilemmas facing teachers and pupils engaged in science and technology education. These commonalties emerge because of the similarities in the dimensions of subject learning
identified in science and design technology in the national curriculum for England and Wales. In particular the focus on process as a significant dimension of domain learning.
This part of the seminar considers some of the similarities and differences in the evolving curricular definitions of science and technology and research evidence about pupils' performance and teachers' practice which reveals some of the dilemmas experienced in the two subjects. Whilst this part of the paper draws on the abundant literature and analysis that has informed debate in science education it does so selectively and from a speculative standpoint. The issues raised will not be new to those with a long involvement in technology education and indeed may at times appear naive. However the intention is to highlight where debate and research have influenced curriculum development and practice in science, the consequences of this and the potential messages for technology education.
The original title of this part of the paper included the word 'lessons' as opposed to messages. However, this suggests that some type of resolution is evident in the science curriculum which is most definitely not the case. What is clear is that the tensions resulting from conflicting influences are now more overt and therefore accessible to debate. Messages from the history of science curriculum development may well enable some of these tensions to be short lived or even avoided in technology to the benefit of the teachers and pupils who suffer most from our inability to think across domains.
1. AIMS OF SCIENCE EDUCATION
One tension evident in the continuing debate about the definition of the science curriculum arises because of views about the nature of science and the purposes of science education. The tensions emerge not just because of differences in views about these which are to be expected and indeed are a healthy expression of the dynamic nature of any domain of learning but because they are rarely differentiated. Often what has been identified as significant for pupils' learning has been criticised because of its misrepresentation of the nature of science. At times there has been considerable justification for these critiques (MILLAR and DRIVER, 1987) at
other times however, they are unhelpful. Particularly when it is suggested that pupils' knowledge needs should emulate those of scientists.
Curriculum definitions depend crucially on views of what constitutes the nature of a discipline and the purposes that subject education should address and for whom. This latter consideration remains controversial in science. In technology the disputes have tended to focus on views of technology and just what can be considered to be technological activity. Defining
technological capability and progression within it has been a relatively recent development (KIMBELL, 1994). Whilst debate has focused on what
the goals of technology education should be it is less clear what purposes such education is seen to serve. A current unresolved dispute in science.
Another tension apparent in the science curriculum debate concerns the distinction between what pupils should learn and how they learn. A typical example of this is the role of problem-solving in science education. For many educationalists, teachers included, a problem-solving approach is emphasised for pedagogic reasons i.e. to motivate pupils and allow 'ownership' of tasks (WATTS, 1991). For others problem-solving is valued as
the most appropriate representation of domain activity i.e. the essence of the subject. There are numerous other reasons given for adopting a problem-solving approach, but the point is that it is the divide between pedagogic aims and subject learning objectives that is the source of the tension. A similar tension is evident in technology both in the definition of the subject and teachers' practice. Such different views of the role of problem-solving radically alter the curriculum experience of pupils in ways not even considered in National Curriculum definitions in England and Wales.
Whilst there are expected overlaps in concerns about technology and science education it is clear that the arguments about the nature of pupils' learning have been much more in evidence in the development of the science curriculum and critiques of it. Views of learning influence what is included in curricular definitions and determine what achievements are valued and how they are seen to develop. Hence a reflection on the learning debates in science and their implications for practice would inform current concerns about models of technology capability. A summary of some of the stated aims of science education provide a background to the later discussions about curriculum dilemmas as well as providing a useful area for discussion across science and technology.
Black (1992) described one of the main purposes of the science curriculum as 'providing a basis for understanding and coping with life' which includes providing pupils with an understanding of the applications and effects of science in society. This purpose addresses the need for pupils to be able to 'look after and to protect themselves and others from the flow of incomplete and misleading information' which in Black's view is an inevitable feature of a democratic society. He describes this purpose as learning from science. Learning about science in his view is the second main purpose of science education and involves learning about the 'concepts and the methods which are combined in scientific enquiry'. His justification for including this purpose is because of the need for pupils to understand science as a human cultural activity. The third main purpose identified by Black is for science education to contribute to the 'general personal and intellectual growth of the pupils'. To this end he sees the
pursuit of 'authentic understanding' of the nature of scientific enquiry as an important goal. His final purpose for science education is to provide pupils with a basis for making choices, together with positive motivation to continue with science learning if they so choose. Black argues that the needs of potential future scientists include those identified for all pupils but also necessitate the provision of additional in-depth work.
Box 1: Aims of Education through science and Education in science
Education
through
Science
• Attitudes • Self-confidence, pride in work • Autonomy and commitment
• Integrity in thought, presentation and debate • Skills • Communication skills
literacy oracy
numeracy, including IT
• General problem-solving skills
• Co-operation and other interpersonal skills • Knowledge • Useful scientific facts
• Knowledge, understanding and appreciation of our world
Education
in
science
• Attitudes • Enthusiasm for science, wonder at physical and biological world
• Humility about limitations of science • Skills • Use of scientific apparatus
• Problem-solving in scientific context • Scientific data analysis and reporting • Knowledge
and
understanding
• Knowledge of the important facts and theories of physical, biological and earth sciences
• Understanding and appreciation of scientific facts, theories and models
• Ability to use scientific knowledge to solve problems
These purposes are reflected in the views of many other science educationists. Hodson (1993) for example, refers to the goals of science education as 'learning science - acquiring and developing conceptual and theoretical knowledge ; learning about science - developing an understanding of the nature and methods of science and an awareness of the complex interactions between science and society ; and doing science -engaging in and developing expertise in scientific enquiry and problem-solving' (HODSON, 1993, p.23). These goals correspond closely to Black's
and to those identified by Woolnough who comments however that 'there is no single unambiguous aim in teaching science' (WOOLNOUGH, 1994). For
needs of individual students even when a national curriculum exists. He provides the summary of possible aims given in Box 1.
The need to discuss aims even when a prescribed curriculum definition exists recognises that it is teachers who mediate policy and are crucial in determining the curriculum experienced by pupils. There is evidence that the divergent aims of teachers critically affect how the process of science and design and technology are experienced by pupils (see Part 2 of the seminar).
How do such aims relate to the science National Curriculum in England and Wales ? The science curriculum for England and Wales is defined in four attainment targets (DFE/WO 1995a). The definition of an attainment target devoted to experimental and investigative science (1) is the policy perspective on what is required to provide pupils with some understanding of how science works through their own experience of doing it. That this experience can be gained through the characterisation of scientific activity as an investigation has been widely questioned and we consider these critiques later. That science education should involve pupils in achieving a body of knowledge is evident in the three other attainment targets : life and living processes (2) ; materials and their properties (3) ; and physical processes (4). What remains contentious is whether this definition of knowledge can achieve the type of purposes now commonly identified for science education. One concern is that if pupils are to adopt scientific ways of knowing then a critical perspective on the scientific culture must be fostered in classrooms. To achieve this it is argued that pupils 'need to be aware of the varied purposes of scientific knowledge, its limitations and the basis on which its claims are made' (DRIVER & al 1994). This perspective
relates to Black's concern with authentic activity. If science education is about a process of enculturation who are the practitioners whose practices and ways of learning pupils need to gain experience of and can this be achieved in the school context ?
For some critics there is concern that the process of construction of scientific knowledge is absent or misrepresented in the national science curriculum definition. For others the concern with reflecting practitioners' knowledge in the curriculum requires more emphasis to be placed on the definition of the skills concerned with 'doing science'. These skills are also considered to be under-represented in the description of attainment target 1. Yet others argue that redefining and recognising the content of investigative work in science 'in its own right' would address both the identified need for public understanding of science and the knowledge requirement for science related employment (GOTT & al 1994). This view is again contentious
particularly with regard to the type of knowledge required for public understanding of science which has emerged as one of the central goals of science education for all. Scientific literacy can be interpreted in a variety
of ways. Without careful analysis of the different meanings of scientific literacy it is not possible to define a curriculum and an associated pedagogy to achieve it. Clearly such an analysis has not informed the national curriculum in science. Furthermore such analysis may lead to the conclusion voiced by JENKINS (1990) that the consequences of defining a
curriculum to empower pupils in relation to some of their anticipated needs as citizens may prove beyond the scope of the school science curriculum and its associated pedagogy. It seems reasonable to speculate that an analysis of the purpose for the technological capability represented in the National Curriculum will reflect the need for similar 'profound and radical' adjustments to the content, organisation and pedagogy of technology education that Jenkins suggests are needed in science.
2. THE PRESENTATION OF PRACTICAL WORK
Science has always been viewed as a practical subject, particularly in English speaking countries in the world. However the practical work advocated in the past typically filled the role of confirming theory in the belief that pupils learnt through practice. The tradition of practical work in science education reflected a common perspective about the nature of science and the purpose of practical work. This consensus, that linked the three sciences, was reflected most clearly in the form of writing about practical that was encouraged. Typically reports of laboratory work followed the aim, method, results, conclusion format. Sutton traces this approach back to a view of science as 'data first and theory later' evident in the notebook format for recording qualitative chemical analysis (SUTTON,
1989). The aim of such an approach he considers is to provide 'defensible evidence for conclusions'. However, such an approach misrepresents the process of data collection and the role of theory, creativity and ideas in this. Consequently it limits pupils' ability to understand scientific ways of knowing and encourages the learning of meaningless rituals.
In most reviews of practical work in science education (Lock 1988 ; Hodson 1992 ; WOOLNOUGH and ALLSOP 1985) reference is made to the
early and radical influence of Armstrong who considered that investigation was central to practical work in science. Armstrong's (1891) heurism had widespread effects on science practice in schools. Armstrong advocated quite a different style of reporting practical activity. In Sutton's words it involved 'having ideas, planning and carrying out tests of them and so developing successive refinements of these ideas' as such it was an ongoing form of writing to represent the process of data collection rather than a defence of the conclusions drawn (SUTTON, 1989, p.140). This description
of practical activity has echoes in the Nuffield approach to practical work and in the approach advocated in Attainment Target 1. The heuristic method
was heavily criticised and its practice restricted in the early part of the century because it was considered to misrepresent genuine scientific activity, led to a neglect of the teaching of scientific concepts and restricted science to what could be studied practically by pupils in the laboratory. It was also judged to be an inefficient way of learning science. Recent criticisms of practical work in science, as we will see, closely reflect those of nearly a century ago (DONNELLY et al 1994).
What is particularly pertinent to current curricular debates is that both approaches to presenting practical work, that of 'discovery' and providing 'defensible evidence' remain evident in teachers' practice. They therefore significantly influence how pupils experience 'doing science'. Sutton refers to the tension that teachers experience in wanting to encourage active thinking whilst holding a belief in the need for 'dispassionate and accurate accounts of things'. We will return to this tension but it might be worth considering whether there is any similarity in the effects of standard forms of presenting work on pupils' understanding of what doing a subject entails in technology. The rituals of the design folder format may also limit how pupils perceive the role of ideas and creativity and the influence of knowledge on their own actions and those of others in technology.
It has also proved problematic trying to represent a model of scientific activity that has applicability across the three disparate subjects of physics, chemistry and biology (BL A C K 1986). Technology is faced with a
potentially greater problem given the range and variation of subjects associated with it.
3. PROCESSES AND METHOD
The role and nature of practical work in science has changed in response to a variety of factors. We consider here the influence of changing views about the nature of science, the purposes of science education and pupils' learning.
There has been an extensive debate in the science education community about science processes and the scientific method which is well documented (WELLINGTON, 1989, MILLAR and DRIVER 1987). Aspects of this debate
that have relevance to technology education include the views about the nature of scientific processes, the characterisation of a scientific method as a generalised process and the relationship between process and knowledge in scientific activity.
During the eighties there was a dramatic increase in the development and implementation of process-led courses. This level of development and implementation has not yet been paralleled in technology education although design and technology, more so than science, is represented as a process subject. The implementation of these process-led courses are of
interest for several reasons. They were developed because of a concern that the content-led curriculum prevalent up till then was judged to have failed. It was also believed that a curriculum that did not emphasise the process element of scientific endeavour was a misrepresentation of the nature of science. Furthermore a process approach was considered to be both more accessible to pupils and more relevant. The relevance of the process-curriculum rested on the belief in the transferability and generalisability of the processes. These justifications for a process curriculum bear some comparison with the rationale for the National Curriculum subject 'design and technology'.
The response of the science education research community to these courses and the premises upon which they were derived was swift and relatively furious. The inadequacy of science education was recognised because of the growing body of evidence that what teachers were teaching, pupils were not achieving, particularly with regard to conceptual understanding (DES 1982a and b ; 1984a and b ; DRIVER 1983, CLIS 1987).
However there was no evidence to suggest that the source of the failure was the absence of process-teaching. The evidence from research pointed more directly to the inadequacy in current understanding about pupil learning and the mechanisms of conceptual change. This led to the present emphasis on constructivism in science education. The belief that the process-curriculum was more accessible reflected a view of learning by discovery. Pupils were judged to discover knowledge by the application of general skills and processes such as observing and experimenting. Consequently processes like observation were assumed to be theory-neutral. A pupil was considered to observe first and interpret second, hence observation as with the other processes was simple, unproblematic and open to all. This inductivist view was, and continues to be, widely disputed.
Research, particularly that of the APU15 science project, had demonstrated that observers pay attention only to those objects or features that are familiar or expected. Pupils' performance on observation tasks was found to be influenced by their prior knowledge and theoretical understanding of the content of the task and science in general (GOTT and
WELFORD 1987, MURPHY 1989a). Processes per se were therefore viewed
as merely common-sense ways of thinking unrelated to domains. It was argued that only the content and context of process-based activities gave them scientific meaning. Thus classifying nails or postage stamps was not judged to be scientific activity as the content had no scientific relevance, whereas the classification of bones etc. was. Of course, the pupil classifying
15 The Assessment of Performance Unit was funded by the Department of Education and Science to monitor the performance of national populations of school pupils aged 10-11, 13 and 15 years of age. The monitoring began in 1978 and ended in 1989 in a range of subjects including science.
the bones might well classify them in a non-scientific way but such a response would be judged inadequate in scientific terms. Hence process tasks are dependent on scientific conceptual understanding. This view of science processes as context and content bound also brought into question the belief that using processes to organise knowledge benefited pupils' learning and enabled transfer. Again the evidence from the APU showed that transfer across process tasks did not occur. The reasons for this were not simply to do with the situated nature of pupils' knowledge but also because small changes in task content and context could alter the demands being placed on pupils. Hence whilst the tasks might share the demand for interpretation such interpretation could vary in the scientific and mathematical understanding necessary to carry it out. However any evidence that did emerge suggested that it was through the content that links between experiences were forged rather than through the acquisition of general rules or strategies.
An outcome of these critiques was a relatively immediate acceptance that processes could not be taught as general content-independent intellectual activities. Moreover it was recommended that the science curriculum of the future should reflect three dimensions : content i.e. the body of scientific knowledge to be achieved ; processes even though there was little agreement of what these were ; and context meaning the context in which pupils' study which was generally agreed to have three elements relating to the individual, society and the whole school experience (KIRKHAM 1989).
One further and significant outcome of the response to the process courses was the concern about the representation of scientific activity as a hierarchical set of discrete processes. It was generally held that there was no algorithm for gaining or validating scientific knowledge. Whilst most of the critics accepted that scientific procedures and techniques existed as did 'rules' governing the conduct of scientific activity, there was a general consensus that the creative nature of scientific activity could not be represented as a universal set of a priori rules (JENKINS 1987). In Hodson's
words 'science does have methods, but the precise nature of those methods depends on the particular circumstances' (HODSON 1993). The point made
about the particularities that govern the process of designing overlaps with the perspective expressed here (see Part 2). Hodson continues :
"By making a selection of processes and procedures from the range of those available and approved by the community of practitioners, scientists choose a 'method' they consider to be contextually appropriate... All decisions are 'local'". (HODSON, 1993, p.14)
In making these 'local' decisions scientists are considered to rely on conceptual knowledge combined with elements of creativity.
This view of investigative activity as context-bound was examined in a small way in the APU science surveys. A population of 13 year-olds were
given the same investigation set in two contexts. The pupils responded quite differently but also quite appropriately to these different contexts (MURPHY,
1989b). These results have been confirmed by later research into pupils' performance on investigations (FOULDS and al 1992).
4. HOLISM IN SCIENCE EDUCATION
To make sense of the form and nature of the National Curriculum definition of science that emerged, and of the problems being experienced in its implementation, it is necessary to stand back at this point and consider the consequences of some of the issues raised already and the other influences on the curriculum and teachers' practice evident at the time.
Firstly, the profession's response to the process-led courses was quite positive. The courses provided clear guidance about what tasks to use and to what end. It was also clear that pupils enjoyed the activities. Furthermore evidence from in-depth studies carried out by the APU science project indicated that performance on process-oriented tasks such as interpreting data, making predictions etc. was improved by these courses. This improvement seemed to arise because pupils were more readily cued to the purpose of such tasks and hence were better able to make sense of them. Consequently more pupils attempted the tasks and achieved some level of success (APU trial data, MURPHY unpublished, 1987). Hitherto many
pupils' low performance in APU surveys was not a consequence of supplying the 'wrong' response but, failing to perceive the assessor's task (DES, 1989). It cannot be said whether such improvement in performance
could be maintained or indeed improved further. More research of a longitudinal nature would have been required and after 1987 research was dominated by the requirements of the national curriculum.
Another factor that militated against further research into process-oriented tasks was concern about the influence of assessment on practice. The criterion-referenced assessment initiatives such as the GCSE (General Certificate of Secondary Education - the public examination taken at aged 16 in England and Wales) were viewed by some as exerting a detrimental influence on teachers' practice as they focused attention on atomised aspects of science performance (WOOLNOUGH, 1989). The consequences of this was
in Woolnough's view to promulgate a step up model of learning science where pupils were encouraged to master basic skills first and then to progress to more complex skills and eventually to whole investigations. The APU evidence reinforced this view of some teachers' practice.
For example, it was found that on the tests of using and interpreting tables and graphs pupils across the ages performed competently (TAYLOR
and SW A T T O N, 1991). However, in the assessments of practical
tables or in graphs. Similarly in the tests of interpretation of data although pupils did not find generalising easy they were able to attempt it and on some tasks they performed well. Again in their response to whole investigations it was rare for 13 and 15 year-olds to offer a generalisation even if the task required it and the data collected allowed it. For most pupils the outcome and end point of a practical investigation was their results. A further example related to pupils' performance on practical tasks assessing the use of apparatus and measuring instruments. In these tests performance was generally quite high except for certain instruments such as ammeters and voltmeters where mathematical demands related to scale often depressed pupils' performance (DES, 1988 ; DES, 1989). However, in
practical investigation a substantial proportion of 13 and 15 year-old pupils failed to take measurements when a quantified approach was the most appropriate (MURPHY, 1988). Interviews with pupils revealed that whilst
pupils knew how to measure, few were aware of the need for quantified evidence or when such an approach was appropriate. The why and when of measurement had not featured in their curriculum experience. These results suggest that the focus on isolated skills provides pupils with rituals that they cannot then apply unless faced with the type of task in which the ritual was acquired. This ritualistic learning appeared to be a feature in the practice of some teachers of technology though more generally ritual learning in technology appears to be related to the teachers' presentation of the generalised process of design (see Part 2).
The response to this concern was the advocacy of the use of whole investigations or problem-solving activities both for assessment and for learning (Woolnough, 1989). This view was supported by the APU work because the assessment framework included a model of investigative activity (GOTT and MURPHY, 1987).
This model (see Figure 1) had the advantage of being available and exemplified through tasks which also had associated performance evidence. However, such models immediately run the risk of inviting the criticisms discussed earlier, that is of appearing to reflect an algorithmic view of scientific activity. The cyclical and iterative nature of the model does not answer such criticism. It is the stages in the model which cause concern to those who see science as a creative, human craft. For those people, and there are a considerable number of them in the science research community, there is no generalised characterisation of scientific activity that is acceptable. However, this response has its limitations.
One significant advantage of attempting to characterise and describe scientific activity is that it forces one to consider what the decision-making process is for the variety of instances that the model purports to represent. Hodson, who was quoted earlier, espoused a view of science activity as contextually bound and dependent on creativity. However in his view, and
others, the only way to learn about scientific ways of thinking and acting is not to learn a prescription but to do science alongside skilled and experienced practitioners. In order to 'do science' pupils and teachers need to make explicit the 'local' decision-making involved in science activity. This requires some definition of procedural knowledge and examples of when and how to use it appropriately and to what end. The APU provided an initial attempt at defining some of the procedural knowledge which has been built on since (MILLAR and al, 1994). This recommendation for pupils
to experience doing science in a holistic fashion is widely accepted, although there are significant critics of an approach which threatens to 'set-up a cottage-industry science in the classroom' (DONNELLY and al, 1994).
Figure 1 : The APU model (Gott and Murphy, 1987)
This advocacy of holism is a central issue in technology education (KIMBELL, 1994). However, as pointed out elsewhere, holism can only be
realised if pupils are equipped with the procedural knowledge to operationalise both their processes and their conceptual and technological knowledge in deriving solutions. Procedural knowledge remains a contentious and under-researched issue in science education and appears largely absent in technology. Holism in science education does, however,
have its problems in implementation, and again this bears some comparison with the problems identified in teachers' implementation of the design process.
The body of research that has examined pupils' prior ideas and the difficulties they experience in developing scientific ones is considerable. This research has led to the widespread adoption of constructivist approaches to learning science, though practice under this broad umbrella term varies considerably. Of note in regard to technology education is the consensus that has emerged about the importance of establishing pupils' initial understandings as they relate to activities along with their perceptions of the activities themselves. Other recent research which has focused progression in pupils' conceptual understanding (DRIVER and al, 1994) has
highlighted the considerable time involved in developing basic conceptions. This raises some issues for consideration in technology practice. First it is rare for explicit account to be taken of the knowledge demands in projects and it is even rarer to establish pupils' understandings either at the beginning or during the course of project work. There is also a pedagogic tradition of delivering knowledge either by direct transmission or by pupil research often conducted as part of a homework. All the evidence that has emerged from science education would suggest that these methods are not appropriate for ensuring the acquisition of knowledge and may for some pupils be inadequate even to get them through a project.
PART 2: LEARNING THE PROCESSES IN TECHNOLOGY INTRODUCTION16
The technology curriculum, especially as manifest in the National Curriculum subject 'design and technology', has been seen as primarily a 'process-based' curriculum. There are of course parallels with 'process science', although in the case of science it was a matter of emphasis, rather than the sole basis of the curriculum as we have argued in Part 117. The role of knowledge has not been denied or ignored by those who advocate processes, but it nevertheless has been seen in a subsidiary role (e.g. KIMBELL and al, 1991). Technology education mirrors the problems in
science education, as discussed by MILLAR (1989), in that it has suffered
from the application of incorrect models of how technological processes, especially design, are actually carried out, and from the way they are implemented in the school curriculum. In particular, design processes are often used in a mechanical way, and are not seen to vary across situations and contexts. This, as we shall show, is manifest in terms of a design process being presented to pupils as both a revelation and a ritual, ideas which are also emerging in the science education literature on investigation (GOTT and DUGGAN, 1993).
In this paper we shall argue that the research literature on problem solving, and the study of designers and engineers, point to the need to move away from such mechanical and algorithmic approaches to designing, and to develop approaches that are sensitive to context, including the nature of the conceptual knowledge that is to be employed. This once again mirrors the science education literature where the link of conceptual and procedural knowledge is now well recognised, even if not implemented in the classroom (MILLAR and al, 1994)18. Now that the National Curriculum for
'design and technology' is stressing knowledge and skills, an understanding
16 The research that this paper is based upon is an ESRC-funded project Problem solving in technology education: a case of situated learning (Grant number R00023445), and any evidence used is taken from this work (see McCormick, Murphy and Hennessy, 1994, for an account of the research questions and methods). We would like to acknowledge the work of Sara Hennessy and Marian Davidson in collecting and analysing the data for this research.
17 Murphy (1994) spells out the relationship of science as process, and the lessons it has for the technology education that seeks to teach such processes as a central feature of the design and technology curriculum.
18 Robin Millar (University of York) and Richard Gott (University of Durham) have an ESRC grant to investigate the interaction of children's conceptual and procedural knowledge in science.
of the relationship between these and design processes is important in developing a sound pedagogy.
1. DESIGNING AS A PROCESS
Designing is seen as a central process in the technological curriculum, one that equals the importance of the 'process of science' in the science education curriculum. Indeed it is perhaps more important to technology educators, because they often see it as existing independent of any particular content. This importance is reflected in the fact that the curriculum area that has now been established in schools is not 'technology' but 'design and technology', in other words seeing 'design' as having significance in itself. In the world outside school few would recognise this 'subject' or this combination as an identifiable activity. People would be referred to as 'designers' (perhaps with a prefix : engineering designers ; product designers), or as 'technologists' (more commonly as 'engineers' or specific kinds of technologists, e.g. food technologists). But the use of the term 'design and technology' serves to acknowledge the central role of design in the school subject, although there are a number of critics of this as a representation of the world of technology outside schools (MCCORMICK,
1990 ; MEDWAY, 1992 ; YOEMANS, 1992). In the literature of technology
education, there are a number of characterisations of the 'design process', and views of how generalisable it is as a process. These will be examined in this section of the paper.
1.1. Models of design
The design and technology literature is littered with representations of the process of design. A very early version was that used in the Schools Council project on Design and Craft (see Figure 1). This sensibly saw design going through both divergent and convergent stages, and in that sense is trying to represent the way thinking changes during the design of an artefact. However, the stages shown on the left, are clearly sequential. Such linear representations ignore the non-sequential nature of the stages in the practice of design, and so circular representations have been created (see Figure 2). The difficulty with both of these representations, is that they are more like representations of projects that inevitably go through specific stages ; it is necessary to 'explore possibilities' before 'refining ideas' and 'making' after 'detailing a solution'. Thus when a Year 8 class is undertaking a 'design and make' task it is necessary for the teacher to show the process as a series of stages that, not only have to be completed in a particular order, but also that particular stages have to be completed by a particular time. Such a regime is necessary to ensure that pupils complete tasks on time and can be supplied with the correct materials and other inputs to carry out the task.
Figure 1 : Design process : Design and Craft Education Project (From Design for Today)Source : Eggleston, 1993, p. 20
Not surprisingly, such an approach resembles models found i n engineering design, which reflect the industrial setting where clear stages are essential in a complex organisation to ensure that work is carried out on time and in an economic and efficient way. The interactions shown in Figure 2 serve to remind us that the thinking process may not be so linear even if the 'designing and making' of a particular artefact is. Other attempts to represent this thinking process do not use the same descriptive language. From the world of design education in higher education, we have diagrams that reject 'a design process' and try to distinguish the needs of the 'design and make' task from the thinking processes in designing.
Figure 2 : An interacting design loop. Source : SEC 1986
Thus in Figure 3 the 'design and make' task in the industrial setting becomes the 'product cycle' contrasting with the way ideas are seen to develop, as shown in Figures 4-6. In the world of school design and technology, the representation of the thinking processes is shown in the Assessment of Performance Unit's version, one that takes the modelling process as a central feature of designing (Figure 7). Although this is a much more sophisticated approach than that represented in Figures 1 and 2, it still has the linear process implied in the vertical axis, because it assumes that modelling starts in two dimensions and finishes in three.
Figure 3 : Product cycle
The main participants and their activities in the promotion, design, manufacture and use of products. Source : OU, 1983, pp.22
Figure 4 : Design convergence in conceptual terms
A designer converts ill–defined problems into well–defined problems : a brief into a design. Source : (O.U. 1983, P.19)
Figure 5 : Evolution of Design
Each revolution represents one turn of the product cycle, moving forward in time. Each successive idea leads to another form of the artefact, which leads to
the next idea, and so on...Source : OU, 1983, pp.24
Figure 6 : Design convergence within the product cycle Source : OU, 1983, p.28.
Figure 7 : The Assessment of Performance Unit model of interaction between mind and hand. Source : Kimbell et al 1991, p.20.
There are well known examples of designers who do not start with two-dimensional modelling or at least very quickly focus on trying their ideas out in three dimensions (for example, James Dyson the designer of the cyclone 'vacuum cleaner' resorts immediately to building and developing his ideas for a design through testing out possibilities).
Three issues arise out of this brief consideration of the models of the design process. First, is the fact that few of these models are based upon what actual designers do, but are idealisations by theorists who wish to represent the process in an abstract form to teach people how to design. Accounts based upon observing designers reveal quite a different approach with, for example, professionals going immediately to solutions and working back to problems. In this sense pupils often act more like the professional designers than teachers may want them to (teachers insist upon several ideas to prevent pupils from focusing upon a solution). Second, such representations imply that all designers work in the same way, and hence all pupils or students must be taught to design in a particular way. The latter is contradicted by practice ; for example, Mark Sanders the designer of a collapsible bicycle, in contrast to James Dyson, draws his ideas many times until he has developed the idea19. Third, such general accounts of designing that these models seek to promote, ignore the particularities of the design
19 The contrast between these two designers can be seen in the video-cassette associated with the course E650, Design and Technology in the Secondary Curriculum,
situation. Designers dealing with a particular product in a particular company or design context, will work differently from those dealing with another product or in another company. MCCORMICK (1994), in reviewing
studies of designers, indicates that these particularities are crucial to understand the process of designing. Such an inevitable desire of educators to teach a generalised process is complicated, however, by the fact that teachers often attach different meanings to what they understand by the design process, whatever the design theorists think. We turn to these different meanings now.
1.2. Views of the design process
The 1990 version National Curriculum Technology (DES/WO, 1990) portrayed a design process through the Attainment Targets for the 'design and technology' profile component :
AT 1 : identify needs and opportunities AT 2 : generating a design
AT 3 : planing and making AT 4 : evaluating
Although this was never portrayed as a staged process, it has an inherent sequence when used as the basis of 'design and make' activities, as noted above. This design process sequence had different significance for different teachers. Many saw it as a uniting feature of their work, giving coherence and rationale for the collection of specialisms of 'craft, design and technology' (CDT), home economics, art & design, business studies etc. This was evident in interviews we carried out and was manifest in a view of the design process as about problem solving :
[design and technology is defined when pupils] take a problem, research it, define it and actually be able to tackle that particular problem in an intelligent way and work their way through the processes they would lead to a solution.
(Head of Technology in a secondary school)
This view of the design process as a problem-solving process is seen to be of use in any kind of problem and to apply outside school, including in later life.
Those anxious to preserve the complexities of the thinking processes in design, and to move away from a mechanical process implied by stages (e.g. KIMBELL et al, 1991), are less concerned with the nature of the overall
process than with the sub-processes that are employed in designing. They focus on such sub-processes as identifying, investigating, planning, developing, and appraising, and see capability in designing as in part being able to employ these sub-processes at appropriate times in a project. Thus, investigating can be carried out in relation to determining user needs, choosing suitable materials, devising suitable production methods, evaluating user reactions to the designed product and so on. Teaching and
learning design and technology therefore needs to focus on how pupils acquire such sub-processes, but also upon the procedural knowledge that allows them to decide when to employ them. Few commentators seem to address the nature of this procedural knowledge, or how it can be taught and learnt. Our interviews with design and technology teachers have not indicated any who subscribe to this focus upon sub-processes, although it could be argued that the latest National Curriculum proposals for design and technology (DFE/WO, 1995b), with their identification of designing skills, requires such a view. As we shall show, approaches that simply take pupils through the sub-processes in an algorithmic fashion do not ensure that pupils will be able to employ the sub-processes independently, as they often have to when they reach Key Stage 4 and above.
Another view is that the overall process of design is seen as having little intellectual purchase, and is more like the product cycle depicted in Figure 3. A teacher of an electronics project, for example, deliberately did not emphasise the design process ; it was not one of his main aims, and he seemed to view it as a logical approach rather than as a process which involved sub-processes that had to be taught and learnt :
"although I'd like them to understand and use the design process and I think it's quite a nice framework for them to fit things on to, I don't think there's a great need to be dogmatic about it and say you must learn it....the nature of projects leads them through the design process despite the teacher's bit, going through it with them in front of the class..."
He appeared to see the "logical approach" as a 'way of working', and in that sense the sub-processes were of little significance to him. For him the design process was very much in the background, not just in this project but in general : "I'm relying rather a lot on a subconscious level of going through things. Some of them won't do it, some will." It resembles, therefore, a planning tool, and we have evidence of this being used even when there is explicit teaching of the overall process as being made up of sub-process (MCCORMICK & DAVIDSON, 1994)20.
Whether or not the three views identified above (an algorithmic approach, a focus on sub-processes, and a planning approach) reflect what real designers do, or are appropriate teaching approaches21, it remains true that pupils will be exposed to teaching that is based upon some such view. This affects the way tasks are structured, the kinds of interventions that are made by the teacher, and the assessment of pupils' work. Not all of these will be consistent either with each other, or with the view espoused by a teacher, but collectively they will have a profound effect on the pupils'
20 This evidence comes from the preliminary results of our third full case study which we are currently analysing.
perceptions and activities. Later we will refer to evidence that illustrates this effect.
But, whatever view is taken of designing, there is a tendency to see it as an algorithm to be applied in a variety of situations. This is neither well substantiated in the problem solving literature nor in that on how designing is carried out, as we shall indicate in the next section.
2. DESIGNING AS AN ALGORITHM 2.1. The problem solving literature
Elsewhere we have examined the existing literature in areas such as science and mathematics (HENNESSY, 1993 ; HENNESSY, MCCORMICK and
MURPHY, 1993). This examination revealed little to support the general
nature of problem-solving abilities, or the transfer of these skills into everyday life. Although the evidence from science and mathematics is almost unequivocal22, there is little substantive research on technology education to draw upon, and it would be premature to cast doubt on the possibility of a general problem-solving ability without a wider research base.
As we argued earlier, models of design processes do not adequately reflect what practitioners do, and the very nature of their intention to act as a general description (and prescription), is undermined by the evidence of research into what designers and engineers do. Such research, when considered alongside that of situated cognition, points to the importance of the process of enculturation in learning mathematics, science, technology or whatever. This entering into the culture of a discipline or profession is the essence of learning, and if it is part of an increasing participation, then it is an apprenticeship (LAVE & WENGER, 1991)23. A critical idea in engaging in
what LAVE and WENGER (1991) call a 'community of practice', is that
activity is authentic. This means it is coherent, meaningful and purposeful within a social framework - the ordinary practices of the culture. Here we have the parallel with traditional apprenticeship, where the apprentice engages in increasing amounts with the everyday activity of, say, the factory. 'Learning the trade' means learning the norms and values, as well as the skills of the trade. None of this implies that pupils in schools are trying to be professional designers, simply that they are trying to understand,
22 Some of the work on general skills, for example by Adey and Shayer, does support the existence of such skills, but this evidence is swimming against the tide of support for domain and context-dependent problem-solving skills.
23 Much of this idea of apprenticeship and situated cognition was developed by Lave and Wenger (1991), who used the term 'legitimate peripheral participation' as a more general term than apprenticeship.
through participation, the nature of technological activity24. It is of course possible to argue that there are differences between 'school design and technology' and 'technology' in the world outside (indeed as RESNICK
[1987] argues they are endemic), but to say that there should be no connection is to create a ghetto culture that isolates pupils from the culture that school has some obligation to prepare them for.
The result of not taking into account the above research, is that students are taught formalised processes, for example in the form of algorithms to solve mathematics problems, or the design process to design and make something. The source of the difficulty for the school is that it denies pupils the opportunity to engage in the community of practice, in other words they do not engage in authentic activities. Instead pupils participate in the school culture and pick up the cues that give purpose to, and success in, school activity ; for example, there should always be four alternative designs or evaluation takes place at the end of the project. Our research indicates that, just as in the research on problem solving, pupils are not engaging in authentic activity, but are picking up the school cues such that they exhibit a 'veneer of accomplishment' in carrying out the design process. This 'veneer' is exhibited in such things as pupils producing four designs, but not as equally valuable solutions to the problem or opportunity, rather as a requirement of the task to have a record in a design folder, that can then be assessed as an indication of their learning the sub-process of 'generating ideas'. In our case studies of pupils carrying out 'design and make' tasks we see this kind of veneer through the teacher presenting the process as both revelation and ritual.
2.2. Revelation and ritual25
The two case studies we report on here involved an art teacher in a design and technology team teaching a Year 8 group (aged 12-13) through the design and make of a kite for a special occasion, and a Craft Design and Technology teacher (in another school) teaching a Year 8 group the design and make of a badge which included an electronic circuit.
The teacher in the kite project was aware of the need to keep in mind all of the processes required by the National Curriculum (DES/WO, 1990). She had decided to emphasise the processes concerned with 'generating ideas' and 'evaluation', and the practical activity of using materials. She stated that she did not want the overall process to be seen as a rigid linear sequence (hence pupils were to "evaluate throughout"), and was concerned in addition to emphasise creativity. By this she meant encouraging the
24 See McCormick (1994) for a fuller discussion of these ideas in the context of technology education.
25 A fuller account of the process as revelation and ritual is given in McCormick, Murphy and Hennessy (1994).
children to experiment with materials and to try out ideas without any preconceived notions of a final product. However, in pupils' minds the over-riding impression of the project, and of technology generally (both in and out of school), was essentially of 'making', and the learning outcomes in design and technology were described as skills related to making. The children appeared to be largely unaware of the design process. In an interview some six months after the project the teacher expressed concern about the National Curriculum processes and felt some conflict between teaching the 'design process' and encouraging learning in art that she valued, i.e. creativity. It is therefore unsurprising that pupils' perceptions would not include these processes.
This conflict in aims led to a lack of explicit treatment of the processes. Despite the fact that the lessons over the eight weeks of the project followed the usual sequence of processes, there was little reflection on them and no explicit discussion of the overall process. This was in part a deliberate pedagogic strategy by the teacher. In order to prevent the pupils becoming focused upon a final product prior to being creative with their initial ideas, she tended to 'reveal' the process implicitly as the class went through the various stages of the project. This reflected her belief that a stage of exploration was critical if pupils were to apply understanding of the materials to the product from an informed and experienced position. Hence creative experience of the materials was seen as pre-requisite to a good solution. This is not to say that the design process was devalued by the teacher, but that to an extent it became secondary to other learning she considered to be more fundamental.
There was reflection on the processes on some occasions. For example, at the beginning of the lesson that followed on from the pupils making a 3-D model and test flying it, she asked the class to consider why a model was needed. Overall though, the general lack of explicit treatment of the processes led to pupils dealing with apparently isolated tasks and caused confusion. For example, one pupil was told by the teacher to draw a full-sized version of her kite when she had finished her 3-D model, without explanation of its purpose. Neither did this pupil have any sense of an overall process to create meaning in the task for herself. Although she was normally a hardworking and motivated pupil, the confusion as to what she should be doing resulted in her wasting the rest of the lesson and doing nothing.
Other examples of where processes were explicitly focused on include when pupils were required to evaluate at various stages in the lesson sequence. However, not until the last lesson were pupils given any structure to the evaluation (through a list of questions to answer). A similar lack of explicit treatment of what the process entails occurred with 'generating designs'. Pupils were asked to produce several designs and they did
elaborate sketches of considerable complexity over the holidays. The parameters for choice of design (the specification) were left open to the pupil to allow 'creativity'. One pupil consequently produced a range of colourful and complex kites, but ultimately opted for a simpler design to make, in response to the teacher's instruction that pupils should choose a design that would be feasible to make and that they could obtain materials for. Hence the relationship between 'generating designs' and 'modelling' within an holistic design process was disrupted. The teacher's knowledge that success is essential to keep pupils involved over-rode other concerns ; hence class management dominated pedagogy. The demand to produce several ideas and then to implement one produced the 'veneer of accomplishment' referred to earlier. The alternative designs produced appeared to play little part in the thinking behind pupils' final solutions to 'meeting the need' (of a kite for a special occasion).
The teacher involved in the electronic badge project began it with the 'Situation' being presented :
A theme park has opened in [place] and it wants to advertise itself. It plans to sell cheap lapel badges based on cartoon characters in the park. To make these badges more interesting, a basic electronic circuit will make something happen on the badge.
This was set within the general title of 'Festivals', but the links to the 'Situation' were not discussed, and from then on no further reference was made to festivals. The teacher continued in the session by asking the pupils to define the 'Design brief' and draw up a spider diagram of 'Considerations' (a specification), tasks which all the pupils seemed familiar with. He did not, however, elaborate on the 'Situation' or the 'Design brief', nor invite pupils to discuss them in the context of the planned project.
The three pupils we followed (B, T and D) produced different design briefs that illustrated how the 'Situation' was interpreted by them. B & T interpreted it as a "button is pressed to light up the eyes", whereas D makes no such inference : "to design and make a clock badge". The implication of these differing interpretations, and the lack of discussion of potential outcomes, is that the pupils had little ownership of the project. Furthermore, their initial ideas of their personal 'briefs' lingered and influenced future tasks. For example, D continued to talk about a "clock face" for several lessons and abandoned the idea only when he realised that the electronics would not be like that of a watch. He also imagines that the battery would resemble that in a watch and was almost incredulous when the teacher showed a comparatively large conventional dry 9-volt battery that he (rightly) considered too heavy for a lapel badge. The teacher's discussion with D about this issue indicated that unlike D, he had not entered into the 'Situation' and 'Design brief' in a meaningful way, but only ritualistically
-his ultimate answer to the problem was to "have a strong pin for the badge", a response D felt dissatisfied with.
The diagram of the 'considerations' was another example of a ritual as it was never mentioned again, not even in the final evaluation, although some of the items on it (e.g. cost) were dealt with during the project. Indeed new ones were continually added by the teacher without discussion, particularly in relation to the making process. These new ones reflected the constraints imposed by the teacher as he worked out his plan for the project (e.g. the materials to be used, the dimensions of the face, and the eyes and nose positions to fit the circuit). These additional considerations, unrelated to the pupils' original design briefs and design ideas, led to problems for the pupils.
Next the teacher gave several tasks relating to drawing the faces for the badge which implicitly reflected the sub-processes of 'generating ideas', 'developing a chosen idea' and 'planning the making'. However, this was again done in a ritualistic way as the following example indicates.
At the end of the first session pupils were asked, for homework, to create four cartoon faces as potential designs for the badge. No parameters were given other than that all four should fit into the design sheet and that pupils should be 'creative'. As with the 'Situation', 'Design brief' and 'Considerations', this step of producing four designs appeared to be a standard one and, again, was accepted without question by the pupils. However, in the next session pupils were asked to re-draw the faces so that they touch the sides of a fixed drawn square (70x70 mm). The reason for this was not made clear until a later session. Evidence from the pupils' folders indicates that pupils had to modify their designs in order to fit these new demands. For example, D had originally drawn a thin 'carrot' character, which he had to distort to make it fat enough for it to touch the sides of the square. The fact that the creation of several designs is perceived by pupils to be a ritual, is seen in D's comments to the teacher implying he had already made a final choice while he is still completing the four drawings. This, along with pupils' acceptance of apparently irrelevant tasks, testifies to the 'veneer of accomplishment' that such an approach produces.
The pupils were following the tightly formed task structure without question, working out the teacher's intentions, and conforming to the usual culture of the classroom as created by the teacher. Thus, when there appeared to be little logic in the process, such as going from an original design to a 70x70 mm size design to a 140x140 mm diagram with dimensions for the eyes and nose, and back to a 70x70 mm final design with dimensions, they did not seem perturbed or alienated from the task, even when it caused them scaling problems, which they had to tackle without support, and when the design (the one thing they had ownership of) was adversely affected.
The teacher in this electronics project deliberately did not emphasise the design process, because it was not one of his main aims. He was the teacher we quoted earlier who saw it as a 'logical approach' and, the fact that his aims focused on the conceptual knowledge and skills involved, led him to structure the task to allow these aims to be achieved.
Despite the fact that learning the processes of design and technology is so important to those who are advocates for this area of the curriculum, it is evident that the agenda of individual teachers, and their varying conceptions of the nature of the design process, affect greatly the access they give pupils to the opportunities to learn it. But this is only one side of the equation, that of procedural knowledge, what of the treatment of conceptual knowledge ?
3. THE ROLE OF CONCEPTUAL KNOWLEDGE AND CONTEXT
The report of the APU Design and Technology project sees capability in design and technology as the interaction of 'conceptual understanding' and 'modelling and communicative facility' through the processes (e.g. evaluation) of design and technology (Kimbell et al, 1991, p. 23). Although the APU model acknowledges the integration of conceptual and procedural knowledge, it says nothing of how the integration takes place and, further, argues that it is just as important that children are "aware of what they need to know as it is for them to actually know it" (KIMBELL and al, 1991, p. 23).
This may be true but it says nothing of the role the conceptual understanding has in the design task. Further the fact that the APU report described the domains to be tested as part of their assessment framework entirely in process terms - identifying and clarifying, investigating, generating and developing, and appraising - reinforces the emphasis upon processes at the expense of conceptual knowledge26.
The secondary place that conceptual knowledge has within the teaching of design and technology may change given the experience of the first few years of the National Curriculum, and the impact of the latest proposals which emphasize the role of such knowledge. Design and technology teachers are rightly concerned that pupils do not just acquire inert knowledge, but are able to use it in the process of designing and making in their project. One of the strategies they use to enable this is to teach knowledge on a 'need to know' basis, i.e. when it is needed within a project. They also have to assume considerable amounts of knowledge from other areas of the curriculum otherwise their task of teaching would become unmanageable. Both of these are problematic, and they under-rate the
26 This problem was related to their need to establish an assessment framework that could operate independent of the specific knowledge area of a task (see Chapter 3 of the report).
difficulties for pupils in learning and using knowledge. Further, the teacher's emphasis on knowledge in a task may lead to a task structure that is dominated by the apparent conceptual demands, with the teacher paying insufficient attention to an analysis of the needs of the task or the demands of knowledge for action. These are the issues we will address in this section of the paper.
Knowledge on a 'need to know' basis
This is an attractive strategy for a design and technology teacher in the situation where separate 'theory' lessons would destroy the motivation that the subject is able to engender in pupils. In addition, the knowledge demands are not always predictable, and hence have to be dealt with as it required. If we consider the electronic badge project, then it is evident that the teacher would be faced with a variety of kinds of knowledge, much of which would not feature in the science curriculum for that year group, or at the very least contains different assumptions about starting points and progression of conceptual understanding. More to the point science educators would be more aware of the conceptual difficulties that pupils are likely to encounter, and in particular the importance of an awareness of alternative frameworks that pupils bring to the lessons. However, technology teachers are faced with a more complex situation than the carefully controlled science lesson, where the conceptual knowledge may be used to structure the tasks. Instead they will have the complexities of knowledge in action and an agenda of technological knowledge in addition to that of the scientific knowledge.
Nevertheless technology teachers are likely to underplay the difficulties in teaching and learning the conceptual knowledge required in design and technology tasks27. In the first lesson of the electronic badge project the teacher was trying to introduce and develop a whole host of terms and concepts that pupils had existing ideas of and which would be used to differing degrees in the project. These terms and concepts are shown in Table 1, along with the ideas or terms used by pupils, indicating their prior knowledge. In the second session of the project the knowledge becomes almost exclusively that which is not familiar to pupils, as Table 2 indicates. The concepts and ideas are mainly concerned with the symbols and identification of components.
27 In many GCSE syllabuses the project work assessment is likely to focus upon the process, with increasingly knowledge being assessed through separate papers.
Time Concept or idea Teacher's term or analogy
Pupils' term or idea (prior knowledge)
10: 15 Circuit Running track D: goes in a complete circle... not a gap in it J: not broken
10: 16 Battery (accepts B's term)
Provides the force (10: 21)
B : power source (10 : 20)
10: 16 Battery positive and negative
Starts at one point Battery symbol and
polarity
[visual]
Cell is part of battery
D says it is a cell 10: 15-10: 16 Direction of flow (what 'flows' is unspecified)
It goes from... and goes to In fact he says this is not what happens [implying electron flow in opposite direction ?]
D: from positive sign.... to negative sign
10: 17 Flow of electrons around circuit 10: 17 Control of flow of electrons Implies a resistor by accepting D's response Switch or a resistor 10: 17 Resistor Slows [electrons] down Lots of little wires....it
has to go further Volts 'v' as battery voltage Volts
Simple resistor Restrict and direct flow of electrons Light dependent resistor [visual] LDR Solar panel resistor colour
codes (being able to interpret)
Four coloured bands give value : first number, second number, number of zero's
[new knowledge]
resistor tolerance (final colour band)
Amount [of resistors] above and below
[new knowledge]
Table 1 : Concepts and terms used in the first session of the electronic badge project
