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Learning about energy: how pupils think in twodomainsJoan Solomon aa Centre for Science Education, Chelsea College, LondonPublished online: 24 Feb 2007.

To cite this article: Joan Solomon (1983) Learning about energy: how pupils think in two domains, European Journal ofScience Education, 5:1, 49-59

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EUR. J. SCI. EDUC., 1983, VOL. 5, NO. 1, 49-59

Learning about energy:how pupils think in two domains

Joan Solomon, Centre for Science Education, Chelsea College, London

Introduction

Trying to find out what children believe about the workings of the naturalworld is at least as old as the early works of Jean Piaget (Piaget 1926). It isonly quite recently, however, that serious attempts have been made to recordand examine their out-of-school views on topics which arise in science. It hasbecome commonplace to emphasize that pupils' minds are not a tabula rasabefore they are instructed; since these previous mental constructs are boundto interact with what we teach them, a new and valuable field of educationalresearch has developed for probing this unscientific science.

Some work has simply emphasized the 'multiple private versions' ofscience that children hold (Sutton 1980). Others (e.g., Tasker 1980, Osborneand Gilbert 1980, Tiberghine and Delacote 1978) have developed differenttypes of interview technique for collecting data and categorizing them.Almost without exception these researchers have commented on thepersistent nature of pupils' views, even in the face of contradictory scienceteaching. Driver (1981) has termed these obstinate systems of thought'alternative frameworks' and called attention to the common trends which areobservable in much of this out-of-school science.

The reason for the commonality of these viewpoints and their per-sistence is not far to seek. As has been pointed out in papers on undergraduatemechanics (Viennot 1979), and school children's learning about energy (Duit1981), these widely held misconceptions are deeply rooted in the societyaround us. In daily conversation and through the mass media, our childrenare confronted with implicit assumptions about how things move, theirenergy and their other properties, which can be directly at odds with thescientific explanation that they learn at school. Outside the school laboratory,these adolescents are continually being socialized into a whole repertoire ofnon-scientific explanations. Examination of newspaper reports and everydaylanguage makes clear the pervasiveness of this subversive process.

From this standpoint the persistence of such socialized knowledgebecomes readily understandable. Even when science teaching seems to havebeen successful, Duit writes that '[these other notions] generally live onunder a thin layer of physical knowledge'. Similarly, Viennot comments thatthese notions are 'highly robust'. But, although both these authors havecorrectly traced the source of such popular misconceptions, they still expresssurprise, and are concerned that means should be found to extinguish them.

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The logic of the situation determines otherwise. Such socialized knowledgecannot ever, by its very nature, be extinguished. Whether or not our pupilsbecome successful in science, they must never lose the ability to com-municate. It would indeed be a poor return for our science lessons if theycould no longer comprehend remarks like 'wool is warm' or 'we are using upall our energy'. What we are asking from our pupils, then, is that they shouldbe able to think and operate in two different domains of knowledge and becapable of distinguishing between them.

These two coexisting spheres—everyday notions and scientificexplanations—are very dissimilar both in their genesis and in their mode ofoperation. Fortunately there is no need to construct, ab initio, any newphilosophical approach to examine these differences, since it has alreadybeen done in almost exhaustive detail by Schutz and Luckmann (1973).

Their theory, briefly summarized, runs as follows. In the normal or'natural attitude' we all tend to categorize our experiences rather loosely—to'typify' them—so that they can be absorbed into 'meaning structures'. Theseare then reinforced by communication with others and by language itself,which gives this 'life-world' knowledge both social value and great per-sistence. Since each practical situation is only in limited need of explanation,such meaning structures will be fragmentary, not logically integrated withone another and tied to the particular type of experience which promptedthem.

During a secondary process of socialization, such as schooling, otherinterpretative systems of knowledge may be learnt. These stand above thelife-world structures, seeking to explain our experiences in another provinceof meaning, and forming what have been called 'symbolic universes' ofknowledge (Berger and Luckmann 1967). The primary life-world structuresare not eradicated by such learning since it forms an overarching system witha radically shifted perspective of interpretation which is foreign to the naturalattitude and considerably more fragile. Its social currency is also muchweaker since it is restricted to a small specialized group, or to certain periodsof time within the school timetable.

Crossing over from one domain of meaning to the other involves anabrupt discontinuity of thought which Schutz and Luckman compared to theshock of waking up from a dream into the real world. This emphasizesanother point of difference: from the everyday perspective, gaps or problemsin the symbolic domain can be ignored, whereas experiences in the real worlddraw our attention back from the symbolic level to the habitual knowledge ofthe life-world. Thus ease of movement between these two domains is notsymmetrical for the two different directions. This is the theoretical standpointfrom which research findings will be analyzed.

Report and results of some new research into learningabout energy

This work centred on the teaching about energy to three fourth-year classesin one comprehensive school. The pupils, aged 14 to 15 years, all coveredexactly the same elementary work in this field, but the composition of the

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LEARNING ABOUT ENERGY 51

three classes was slightly different. One class, 4P, was taking a traditionalcourse in Physics alone and contained a wide range of abilities. The other twoclasses were studying a mixed Physics-with-Chemistry course; here onegroup, 4PC1, contained the higher ability children choosing this option, asjudged by performance in two tests taken earlier in the year, whilst those oflower ability were in the class labelled 4PC2.

Evidence of the progress of pupils' understanding of energy wascollected in three different ways: by recording class discussions, by testsadministered through normal homework, and by questions set in an end-of-year examination. In this way, it was possible both to follow the progress ofindividual pupils and also to obtain some indications of general trendswhenever they appeared.

For the purpose of this paper we will now move to that point in theteaching programme where the transformation of energy was being learnt.Recordings of class discussions had shown that this, unlike the principle ofconservation of energy, gave rise to little apparent difficulty. The pupils wereshown how to construct 'energy chains' whereby the different forms ofenergy were connected by arrows to show their successive changes. Theexamples given in class included an electric heater, solar energy andhydroelectric power, human movement, the motor car, dynamo, motor,battery and many others.

At this point the pupils tackled a test which contained the questionshown in figure 1. This was designed to find out how well they could trace theenergy changes in the operation of an electric drill. It is with responses to thefinal part of this question that we are concerned.

Figure 1. Test question: 'An electric drill, working at a rate of 500 watts, isused to drill a hole in a piece of wood. How much work could it do in 20

minutes? What energy changes are taking place?'

It turned out that the children's own feeling about the easiness of thetask was justified—the overall success rate was 81%. However these correctanswers were presented in a number of different ways. The formalism whichthey had been taught for answering this kind of question would haveproduced the simple chain

electrical energy-*kinetic energy-*heat energy.

In practice this was the commonest type of answer but, there was also a self-selected group of pupils who chose to include non-energy terms (inparenthesis, not within the energy chain) in order to amplify or explain theiranswer. This formally unnecessary use of extra words gives valuable

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into the pupils' mode of thinking. In terms of Schutz and Luckmann's theorywe have here some clear instances of pupils operating in two differentdomains, crossing over from one to the other and distinguishing betweenthem, as is evident from figure 2. The schematic mapping of answers bringsout three important characteristics:

(a) The energy terms in the symbolic domain serve a selective,clustering function. The pupils need to pick out certain features andignore many more; they need to abstract in order to identify the typeof energy. But these terms are more than higher order generalizationin another plane since they have an over-arching interpretivefunction.

(b) Both domains include explanatory networks. In the life-world itwould be commonplace to comment that electricity causes the drillto rotate, and that the cause of the heat lies in the friction between thebit and the wood. There is no suggestion that such explanations arewrong: they are just not concluded at the appropriate level foranswering the question. In the symbolic domain the network is not,in this instance, so strongly causal. Nevertheless the concept oftransformation allows us to construct a pathway from one energyform to another, just as the principle of conservation would allow usto deduce that the total quantity of energy must remain unchanged.

(c) It is necessary to refer thought from one domain to the other.Abstraction from the life-world is necessary to reach the energyplane, and any inference made here will have to be referred back tothe life-world for verification. In this case very little work is actuallydone at the symbolic level, but this is rather unusual. In moresophisticated physics far more analysis, often of a mathematicalnature, is carried out before the result is referred back to the life-world for interpretation.

Symbolic Domain

Hand /operating/switch

Cable

Plug

Life-world Domain

Figure 2. Schematic mapping of pupils' responses to the second questionin figure 1.

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LEARNING ABOUT ENERGY 53

The first stage in our analysis of the pupils' responses is to separate them intosix categories as follows:

Category 1: A complete and correct energy chain.Category 2: A partially complete, but correct energy chain (oftenomitting heat).Category 3: A correct energy chain with one or two words added fromthe life-world, but used in such a way as to show that they were notincluded in the energy domain; e.g., electrical energy-^kinetic energy-•heat energy (friction).Category 4: An extension of the previous category in which an almostcomplete system of cross-references to the life-world is given, e.g., 'theelectrical energy going into the drill changes into kinetic energy which byfriction drills the hole and changes into heat energy'.Category 5: One or two words from the life-world used wrongly withinthe energy chain, e.g., electric-»kinetic-+heat-»friction.Category 6: Completely wrong answers; question obviously not under-stood by pupil.

Table 1. Classification of pupil answers by response categories describedin the text.

Class

4P4PC14PC2

Total

1

68

11

25

Number2

471

12

of answers3

340

7

in4

310

4

categories5

220

4

6

205

7

Total

202217

59

The analysis of pupils' responses (which is given in table 1) shows thatout of the 48 pupils with substantially correct replies there was a group of 11who deliberately crossed over and back between the two domains withoutlosing their power to discriminate between them. We have no directindication about the way in which the remaining 37 pupils in the first twocategories thought out their answers.

A reading of Schutz and Luckmann's theory suggests two hypothesesagainst which these results may be tested. These are as follows.

Hypothesis I: Lapse of time will select preferentially for the life-worldstructure of meaning if there is no further reinforcement of symbolicknowledge.Hypothesis II: Successful crossing over and back from one domain toanother will be more difficult than continuous operation in one domain,and is indicative of a deeper level of understanding.

An attempt to examine these hypotheses was possible on the basis ofpupil responses to a second question of a similar kind to the one above, which

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was given to the same pupils in the end-of-year examination. For pupils inclasses 4P and 4PC1 this occurred about 2\ months after the energy course,with no further teaching about energy in the intervening lessons. For theother class, 4PC2, this examination took place immediately after thecompleted energy course. This question is shown in figure 3. The answers tothis question were anlysed both pupil by pupil, in order to compare theiranswers with those they had given to the question about the drill, and alsointo the same categories as in table 1. The results are shown in table 2. It isimmediately clear that the class 4PC2, for whom there was no lapse of time,was the only class to show an improved performance on the second question.Closer inspection showed four cases of substantial improvement fromcategory 6 to category 2. The other classes contained no such cases. Therewere only two cases of substantial deterioration in class 4PC2, compared withseven in class 4P and five in class 4PC1. This is all the more surprising sincethis latter class contained those pupils judged to be less able from theirperformance in previous examinations. Of the twelve previously successfulpupils in classes 4P and 4PC1 who now failed to answer the questioncorrectly, there were seven who reverted to using life-world terms in thewrong domain and five whose failure was due to muddling the energy termsas a result, perhaps, of simple forgetting. Thus over half the failure rate canbe attributed to life-world knowledge obliterating learned meaning struc-tures, and this lends support to our first hypothesis.

Flywheel

Boiler

Figure 3. Question in the end-of-year examination (the diagram refers tothe model steam engine used during lessons): 'Name all the energy

changes taking place in a coal-fired steam engine or turbine.'

Table 2. Analysis of pupils' answers to the question given in the caption tofigure 3.

Class

4P4PC14PC2

Total

1

453

12

Number2

19

11

21

of answers3

010

1

in4

400

4

categories5

331

7

6

842

14

Total

202217

59

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LEARNING ABOUT ENERGY 55

In order to test the second hypothesis, only the two classes 4P and 4PC1were considered since they had been exposed to the same lapse of timebetween the two tests and because they contained the group of pupils whohad given answers in categories 3 and 4 in the first test and who had thereforecrossed over between the domains. Looking at the overall trends of change,there is evidence that pupils in the different main categories fared differently(cf., table 3). The following main findings are noted:

(i) Pupils who were unsuccessful the first time (giving category 5 and6 answers) fared no better on the second question.

(ii) A substantial proportion of pupils giving correct answers incategories 1 and 2 on the first occasion, were later unsuccessful inthe second question (categories 5 and 6).

(iii) A majority of pupils giving answers in categories 3 and 4 on the firstquestion chose the snorter, correct method (categories 1+2) whenanswering the end-of-year examination question. Only one pupilmoved to an incorrect (categories 5 + 6) answers.

Table 3. Analysis of pupil movement between the categories (classes 4Pand 4PC1 only). The assymetry in the data is statistically significant at the

0001 level.

Question on the electric drill(by categories)

1 + 2 3 + 4 5 + 6

Question on the 1+2steam engine 3+4(by categories) 5 + 6

122

11

731

006

Thus it seems that pupils who had demonstrated their ability to cross overbetween the domains without error, possessed the more secure understand-ing of the abstraction of energy and its transformations. This is clearlybrought out by the following data:

Pupils initially in categories (1 + 2): 25 Number successful in secondquestion: 14Pupils initially in categories (3 + 4): 11 Number successful in secondquestion: 10

Tests were then applied to pupils in these three gross categories to examinetheir relative abilities in physics as measured by the percentage score theyobtained in the whole end-of-year examination. A comparison betweencategories (1 + 2) and (5 + 6) showed a marked difference in mean scoreswhich was significant at the 1% level. Clearly success or failure in this energywork is strongly related to ability in the other branches of physics tested inthis examination paper. Pupils in categories (3 +4) also had a slightly highermean score than those in categories (1+2), but this was not statisticallysignificant at 20%. From this we may infer that the markedly better

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performance by those pupils who had elected to answer the first question bycrossing over between the domains and were not confused by the process,was not simply the result of this group containing more of the able pupils. Wemay suggest that crossing over between the two domains is substantiallymore taxing than operating in the (symbolic) energy domain alone, and thatthe greater durability of knowledge shown by those in categories (3 + 4)supports our second hypothesis.

Application to other research data

This work on pupils' domains of thought arose out of some research designedto examine a much broader spectrum of their ideas about energy. Thenumber of pupils involved was necessarily small, but the theoreticalstructure used in this analysis has wider application and can be tested ongreater numbers if, for example, we use the data collected by Viennot (1979).Her work examined students' responses to problems in which objects of thesame mass but with different velocities, were travelling in situations whereeach was subject to the same force (the latter was not stated and had to beinferred by the student). Three of the kinds of question used by Viennot areillustrated in figure 4. The first two illustrations (a) and (b), refer thought tothe life-world structures of meaning. Viennot quoted newspaper articles andscientific journals to present a convincing case that speed (or velocity) isintuitively related to force in what Schutz and Luckmann would have calledthe 'natural attitude'. It is interesting to note, in this context, that speed hasbeen shown (Hibel and Wiesal 1962) to be perceived directly by structuresbehind the retina, whereas acceleration (as opposed to the inertial forceswhich it produces), figures much less prominantly in the life-world domainof explanation. For the purpose of testing our first hypothesis on Viennot'sdata it seems better to use the example in figure 4(b) since further teaching ongravitational or other fields of force is likely to figure in university courses,whereas oscillation on springs is a typical school topic which is rarelyencountered in undergraduate physics.

/ // // // // /

i/ /

\

i\

(a)

-Equilibriumlevel

(b)

Figure 4. Examples of question types used by Viennot (1979).(a) Free trajectories under gravity(b) Same displacement at the end of a spring.(c) Theoretical problem: 'If the same force acts on two identical

masses, are the motions necessarily identical?'

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Students were asked what forces were acting upon the masses involved.For both French and British samples the percentage of students whoanswered this correctly declined markedly as students became more andmore remote from their school learning, as the figures shown in table 4demonstrate. Lapse of time, it seems, is indeed selecting preferentially forthe life-world structure of meaning in accordance with hypothesis I above.

Results obtained from the third type of question are particularlyvaluable for our purpose. Here is a problem with no direct link with any life-world situation; it can be asked and answered entirely in the symbolicdomain. Having no necessity to cross over from one domain to the otherremoves a considerable mental hurdle, and hypothesis II would then predicta higher success rate for this question. Viennot reported that over 80% of hergroup of students gave the right answer here, whilst only 58% of the samesample could give the correct response to the question illustrated in figure4(a). We notice that the reasoning required to answer 4(c) should haveensured success in 4(a), had it not been for the visual details in the illustrationwhich drew the attention back into the habitual domain of thought wherespeed is loosely explicated by the action of a similarly directed force.

It is also interesting to examine from the same theoretical stance someresearch on the teaching of energy obtained by Duit (1981) in Germany. Aconsiderable programme for developing methods for teaching the conserv-ation of energy was mounted by him since this topic is generally consideredmore difficult than the transformation of energy (see above). It is very clearlyin conflict with socialized knowledge which holds that energy is 'used up'during useful processes. In the problem below, pupils of approximately thesame age as those involved in the energy studies reported in the previoussection, were asked to predict the highest position that the ball would reachon the other side of the track upon being released from the point shown. Theywere also asked to give reasons for their answers. In spite of the considerableemphasis which had been laid upon the height of rise of a weight and itspotential energy in the preceding course, the success rates in (b) and (c) weredisappointing. Pupils' explanation showed how their thinking had slippedback from the symbolic energy domain into the life-world realm ofexplanation as the more complicated features of the exaplanation stimulatedcrossing over.

Table 4. Percentage of students answering the question 'What forces areacting on the masses involved?' correctly (cf., figure 4).

School Universitylast year 1st year 2nd year 3rd year

48 37French

studentsEnglish

students 64

70

57

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(a) (b) (c)

Figure 5. Test situations used by Duit (1981).

Conclusions

Physics problems are commonly set and illustrated within a familiar context.The reasons usually given for this are that it makes (i) the situation morereadily comprehensible, (ii) the question more interesting and (iii) theproblem easier to conceptualize. Results discussed in this paper cast veryconsiderable doubt on the last of these speculations. It is suggested that suchillustrations can all too easily cause pupils to relinquish their grasp on learntsymbolic knowledge for the familiar everyday system of explanation, afterwhich crossing back again can prove extremely hard.

The tenacity with which life-world explanations adhere to familiarsituations has not passed without comment. Dreyfus and Jungwirth (1980),reporting on the prompting effect of everyday situations on the criticalthinking of pupils wrote 'the non-selective population (of pupils) didsignificantly worse in everyday contexts'. This finding is confined toeducational research within schools. Donaldson (1978), in her powerful andsympathetic book Children's Minds, refers to research by Henle (1962) on asample of graduate housewives which shows how hard it was for them toapply their critical faculties to propositional arguments presented in aneveryday situation where the life-world explanations had so secure a footing.

Donaldson uses this and other examples to differentiate betweenembedded modes of thought (life-world structures) and disembedded modes(symbolic domain). Although she argues eloquently about the difficulty andover-valued nature of disembedded thought which many children find soforbidding at school, it is doubtful if all her conclusions are substantiated byour evidence. Everyday 'human sense' situations do not necessarily makelearning easier. However she also writes of symbolic thought that it 'yields itsgreatest riches when it is conjoined with doing'. Although the theoreticalmodel developed in this paper stresses the demanding nature of such a union,no one would cavil with the high value that she sets upon its outcome. Thedeepest levels of understanding are achieved neither in the abstract heights of'pure' physics, nor by a struggle to eliminate the inexact structures of socialcommunication, but by the fluency and discrimination with which we learnto move between these two contrasting domains of knowledge.

Acknowledgement

I am very grateful to Professor Paul Black for many helpful comments madeduring discussion of this work.

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