Research in Science Education, 1985, 15.

REALISTIC EXPECTATIONS FOR TRADITIONAL

LABORATORY WORK

Barry Newman

INTRODUCTION

Laboratory work is generally regarded as a necessary and highly significant

component of the science education experience provided for secondary school

students. In what follows some attention is paid to the high exteem in which it is held,

a brief analysis of the nature of traditional laboratory activity is provided and a number

of problems associated wi}.h such activity are outlined. It is then argued that

traditional laboratory work is unable to achieve much normally expected of it. Certain

alternatives to traditional laboratory activity are regarded as more satisfactory in this

connection and the paper concludes with a plea for realism and responsibility.

There is little question that laboratory work is widely accepted as being of

considerable value. One has only to look at the lists of objectives associated with

laboratory work that are put forward to science education or proposed for research

purposes (e.g., see Anderson, 1976; Beatty and Woolnough, 1982) to realise that people

have high hopes for science practical activitites. Such objectives relate to much of

what science teachers probably want to do in science education as a whole.

TRADITIONAL LABORATORY ACTIVITY

It is not uncommon in articles on laboratory work to refer to it as though the

reader would readily understand what the writer has in mind. What is in fact envisaged

is a somewhat standard picture of laboratory activity. There are of course variations

on the pattern but traditional laboratory work can be described as follows:

A f t e r a b r i e f i n t r o d u c t i o n by the t e a c h e r exp la in ing wha t has to be done and how it has to be done, the s t u d e n t o p e r a t e s upon some m a t e r i a l s and e q u i p m e n t to

bring about some transformation of the same. The student may then have to process certain data available before, during and after the transformation process, ordering it, treating it mathematically etc. During the hands-on activity and/or at its conclusion the student is prompted to communicate ideas related to the activity with other students and perhaps the teacher, and is often required to commit some material to writing. At the conclusion of the activity the teacher works with the class as a whole, attempting to have the students think about what has been done, what has been observed, calculated etc. and its significance.

One of the common aims associated with tradit{onal laboratory work is to assist

students to develop an understanding of the 'facts', concepts, principles and theories of

science.

PROBLEMS ASSOCIATED WITH TRADITIONAL

LABORATORY WORK

It has been argued elsewhere (Newman, 1981) that traditional laboratory work, is

thwart with difficulties: e.g.,

I.

2.

4.

There are many factors that can be brought to bear upon the student with his/her

understandings, capabilities and attitudes - fellow students, the teacher, the

textual material, the physical learning environment, equipment and materials,

data processing, the processed data, the formal communication process and the

communicated material. There are so many factors that the possiblility of

something amiss leading to an aim no being realised is high.

Problems occur. Who has not witnessed the dissection of the left ventricle rather

than the right; an ammeter, but not the voltmeter reading zero; the 'north-

seeking' pole of the compass needle pointing south?

Information necessary for understanding the principle to be learnt is not

available. For example, a student who has to learn about relative ionic mobilities

is not told that the molarities of all solutions are equal. He/she was expected to

realise that different fractions from a distillation had different boiling ranges

when no thermometer had been used for fear of breakage.

Some exercises, contrary to the intention of the teacher, give misinformation.

The powdered magnesium took longer to react with the acid than the same mass

of magnesium strip. The aqueous humour of the sheep's eye was f i l led with black

specks.

I0

5. Traditional laboratory exercises involve the student in considerable manipulative

activity and is accompanied by data processing and writing. Given the extent to

which these matters dominate the 'hands-on' activity, it is unlikely that many

students have much time to think about what it all means.

WHAT TRADITIONAL LABORATORY WORK

IS UNABLE TO DO

Given the nature of traditional laboratory work;

It is unlikely that many 'facts', concepts, principles and theories of science will be

acquired directly.

It is not geared to provide an understanding of the nature of scientific 'facts', etc.

If students are to learn cognitive processing skills then it is a very poor tool.

It might give the misleading impression that most knowlege and understanding can

properly be gained through laboratory work, and that skills simply can't be learnt

for there's never enough time to practice or that they're too elusive to determine

their features.

Of course traditional laboratory work or any laboratory work may make

significant contributions in other areas - in developing interpersonal relationships for

example, or in helping students to have a more positive (or less negative) attitude

towards school science~ Yet it is unlikely that educators would argue on these grounds

alone that laboratory activities should occupy a prom inent place in science education.

ALTERNATIVES TO TRADITIONAL LABORATORY WORK

If the conventional type of laboratory work is singularly so unsatisfactory other

alternatives have to be sought. Two general types are available: highly structured,

unconventional laboratory work, and laboratory work which is not laboratory work!

(a) Highly Structured Unconventional Laboratory Work

In highly structured unconventional laboratory work the laboratory is geared

towards the attainment of clearly specified goals. One method is that described

in Novak's 'Learning How to Learn Program" (1980). In his scheme the student's

II

attention is upon the identification and characterisation of suitable 'focus'

questions and objects/events that are central to an inquiry.

Another scheme is that involving Karplus' 'Learning Cycle' (1977). There are three

phases of learning to the cycle: exploration, concept introduction and concept

application with laboratory activity playing a significant part in the first and last

phases.

Whether any of these methodologies will, more so than conventional laboratory

activity, lead to the attainment of goals for science education is an open

question. What each has in its favour is its highly specific orientation.

(b) Laboratory Work which is NOT Laboratory Work

The second general type of alternative is one where the laboratory exercise is out

of the pupil's control. It could be that no real laboratory exercise is performed.

The teacher demonstration, the filmed experiment (for an example see Ben-Zvi et

al__., 1976) and the computer si~nulated experiment (see Moore and Thomas, 1983)

are three examples of this type. Presumably, the exercise would proceed as

anticipated.

Whether any of these methodologies will be successful is uncertain, but there are

at least three things in their favour. The chances of the exercise not going

according to plan are minimal, misleading characteristics can be dealt with and

the time required is normally less than that for student controlled laboratory

work.

A PLEA FOR REALISM AND RESPONSIBILITY

At the heart of this paper is a plea for realism and responsibility. Conventional

laboratory activities do little more than maintain or develop a positive attitude towards

school science, and as a-not-insignificant-consequence, encourage some science

students to pursue further studies in science.

Highly structured, unconventional laboratory work, with it high speci f ic i ty , might

well bring about the acquisition of skills needed for sc ient i f ic prac t ice , the acquisi t ion

12

of knowledge and understanding of the nature of scientific practice, and awareness of

some affective characteristics associated with scientific practice as well as the

acquisition of some of those characteristics. It can also be used to teach the 'facts',

concepts, etc. of science but, as with traditional laboratory work, one should not have

high expectations of accomplishing a great deal in the time available.

Laboratory work that is not laboratory work involves a very different approach.

One might expect to teach more of the 'facts' etc. of science than with the student-

centred laboratory activities. Students might acquire cognitive skills through this

methodology though it is highly unlikely they would best acquire psychomotor skills

through such an approach. Students can acquire a knowledge and understanding of the

nature of scientific practice but are unlikely to develop significant affective

characteristics helpful for scientific practice.

A more realistic and responsible approach to laboratory work means using a

variety of methodologies while recognising that some will do a better job than others,

and that, for different students and different goals, different mixes of methodologies

are more appropriate. Laboratory work has its place, but it deservesa more thoughtful

place than is traditionally the case.

REFERENCES

ANDERSON, R.O. The Experience of Science: A New Perspective for Laboratory 'reaching, Columbia University Teachers' College Press, New York, 1976.

BEATTY, J.W. & WOOLNOUGH, B.E. Why do practical work in II-13 science? School Science Review, 1982, 63___(225), 768-770.

BEN-ZVI, R., HOFS'rEIN, A., SAMUEL, D. & KEMPA, R.F. The effectiveness of filmed experiments in high school chemical education. Journal of Chemical Education, 1976, 53___(8), 518-520.

KARPLUS, R. Science teaching and the development of reasoning. Journal of Research in Science Teaching, 1977, 14___(2), 169-175.

MOORE, J.L. & THOMAS, F.H. Computer simulation of experiments: A valuable alternative to traditional laboratory work for' secondary school science teaching. School Science Review, 1983, 64___(229), 641-655.

NOVAK, J.D. Teacher Handbook for the Learning flow to Learn Program. New York State College of Agriculture and Life Sciences, Cornell University, Department of Education, Ithaca, 1980.