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Research In Science Education, 1988, 18, 283-289.

HELPING STUDENTS LEARN IN CHEMISTRY

Brendan Sehollum

INTRODUCTION

There is research evidence from within New Zealand (e.g. Carr, 1984; Burns, 1982)

and overseas (e.g. Johnston et. al., 1971) describing the nature and range of difficulties

senior students in secondary schools have in learning Chemistry. There is less evidence

described in the research literature, of strategies used to help students learn Chemistry.

There are, however, many teachers who are intuitively aware of many problems faced by

learners in Chemistry (and indeed, in Science) and some of these teachers often devise

realistic strategies for helping overcome some of the problems encountered. Most often,

these strategies are not formalised, nor made public and shared with other teachers in

particular, nor are the teachers' efforts evaluated appropriately.

From another perspective, there is now the powerful intent and persuasive evidence

from the PEEL project (Baird and Mitchell, 1986) showing how teachers can work together

in helping students learn, as well as reflecting deeply on the processes involved, and their

outcomes. The vivid, honest account of the PEEL group at Laverton High School in 1985-6

was very helpful in mounting an inservice course for Chemistry teachers in Auckland in

1988.

As the research co-ordinator, the author wished to work alongside a small group of

energetic, interested teachers to formalise effective strategies used in their classrooms,

and communicate these to others. It was hoped that pairs of teachers in schools would

work together for mutual support, but individual teachers were welcomed also. The intent

and desired outcomes of this Action-Research Project are shown in Table 1.

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INPUT

DESIRABLE OUTCOMES

TABLE 1 INPUT AND DESIRED OUTCOMES OF THE IMPROVING THE

LEARNING OF CHEMISTRY PROJECT

Students Participation in surveys, practicals, in an open way. Be prepared to talk about own learning and learning processes

Teachers Research Co-ordinator Meetings Reading research papers Devising strategies

Implementing Monitoring Evaluations Evaluations

More effective learning in Chemistry including: a clearer understanding of key processes and strategies used in learning greater independence and self analysis in learning

Professional development Feedback of own More effective in teaching from teacher education peers, with research Input to teacher data gathered inservice courses

Thus, early in 1988, a 12 hour (6 x 2 hr) inservice course was offered to local

Chemistry teachers using the above rationale. As a result of the course, it was hoped

that teachers would be prepared to carry out some action-research of their own making

in their own classrooms. Fifteen teachers enrolled in the course, which involved four

input sessions and two workshop sessions where possible research proposals were

discussed and clarified.

IN PUT SESSIO NS

I. Identifying Effective Learning Strategies

The purpose of this session was to identify, in groups, sets of effective learning

strategies in Chemistry and to identify limitations to the implementation of these

strategies. Examples provided of effective strategies included:

students having receptive attitudes to Chemistry;

awareness by the teacher of students' existing understanding and knowledge so that

learning goes from the familiar to the unfamiliar;

students perceiving the subject as relevant and useful to everyday life;

adequate physical resources for practical work;

consistency of usage in chemical language;

teachers keeping abreast of changes in theoretical perspectives.

The latter part of the first session was spent with the teacher participating in an

exercise as described by Fensham (1984). This exercise, involving prediction, observation

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and explanation helped focus on problems students have in Chemistry; for example,

rationalising or manipulating observations to fit with predictions.

2. Problem Solving

The term "problem-solving" was clarified and defined including how it differs from

low-level mental exercises commonly found in Chemistry texts. Time was spent in

determining examples of problems that would be worth solving in the senior school; for

example:

Why does soap remove some stains but not others?

Why does food "go ofl ~' more slowly in a fridge than in the open?

Considerable time was spent in investigating problem-solving strategies through the

work of Larkin and Reif (1981). This led to some immediate classroom trials as will be

shown.

3. Mastery Learning

The focus of this session was analysising the work of Bloom through his "Two-

sigma" paper (1983), and the potential of mastery learning in Chemistry. After the

expansive and divergent thinking implicit in the previous session, this session had a much

narrower focus of attention; i .e. Bloom's evidence of how he and his colleagues

researched how students in classroom situations could attain the high levels achieved in

one-to-one tutoring.

The teachers evaluated the purpose, desirability and application of mastery learning

in senior Chemistry, and focussed on one section of the senior course- Acid-Base

Chemistry.

4. PEEL Findings

In this session, the background to PEEL, the processes and strategies used, and

some of the findings were outlined. Examples of concept mapping, and reverse

questioning, were trialled in a Chemistry context.

This session had quite an impact. Continual reference to the Laverton High School

experience (Baird and Mitchell, 1986) with its vivid examples and accounts of teachers'

and students' thinking about learning was helpful in a variety of ways: the energy of the

teachers involved, their honesty and analyses of their own actions, and the reaction of

the students. The success of PEEL has been described by Baird, Mitchell and Northfield

(1987).

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5,6 Workshops

These sessions allowed teachers to raise issues of greatest concern to themselves,

to talk and formulate possible further action. But because there were such demands on

the teachers (e.g. New Zealand's first Focus on Science and Technology Week was about

to begin) and the end of term was approaching, specific research proposals were not

clearly developed. For some, the course had already served its purpose - exposure and

discussion of several issues central to effective learning.

Over the next two months several research proposals did crystallise. Two guiding

principles at this stage were those of "ownership" and "high morale". Guy Claxton at a

recent seminar at Auckland explained his meaning for these terms. Teacher change

towards more effective teaching/learning is more likely to occur if the teacher can make

some actual claim to ownership of the change, and if the teacher's morale is high; that is

there is not co-ercion or guilt associated with the change. The following proposals, and

actions are those of teachers involved in the course.

RESEARCH PROPOSALS

I. Acid-Base Theory

As Cart (1984) has shown, acid-base theory is currently surrounded by confusions

and traps for the unwary. One source of confusion is the way teachers and teacher

educators use aspects of the models developed by Arrhenius and Lowry-Bronsted too

readily.

Another source of confusion is that of the terms "strong" and "weak" as applied to

acids and bases. The Lowry-Bronsted model shows a relationship between acids and their

conjugate bases. That is, the conjugate acid of a strong base is a weak acid model; e.g.

the conjugate acid of hydroxide ions is water.

But consider the converse; the conjugate base of a weak acid (e.g. ethanoic acid) is

a strong base (ethanoate ion) this is clearly inaccurate.

This teacher believes that we should be using these terms -strong, weak and

negligible - in describing or classifying both Lowry-Bronsted acids and bases, and

provides many examples.

2. Mastery Learning and Acid-Base Chemistry

Two teachers at one school decided to write and trial a ten-hour unit on Acid-base

Chemistry at Form 6 (Year 11) using mastery learning. They decided that the unit would

include:

a) a short pretest leading to remedial exercises on Chemical

language/formulae for any pupils who were not able to answer several

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items accurately. Other items on general properties of acids were part of

the formative assessment.

b) a clear list of objectives of the unit for all students at the beginning of the

unit. Students were expected to use this as their guide for learning.

c) three short, mid-unit mastery exercises; students would have extension

exercises or remedial exercises depending on their achievements.

d) practical exercises for students to demonstrate techniques involved in

accurate volumetric analysis; e.g. making a standard solution, pipetting.

These would be further tested in a more formal practical test.

The teachers are working towards high mastery by their students in this topic

rather than accepting a more normal distribution of achievements as has happened

previously, when they used an end of unit test as the main assessment instrument. But as

well the two teachers wanted to have their students reflecting on their own learning and

have adapted the Learning Checklist (Baird and Mitchell, 1986, p. 77) to be used

alongside two sections of this topic.

3. Problem solving and Stoichiometry

After the session on problem solving, one teacher who was just beginning the topic

"The Mole Concept" with her sixth Form class, decided to explore her students' ability to

solve problems without her usual highly structured examples and exercises. In the first

lesson she set the following problem:

"Given that hydrogen and oxygen react to form water, how much of each would you

need so there is no hydrogen or oxygen left over".

Individuals worked on the problem for about ten minutes before there was any class

discussion. The important issues of balancing an equation, comparing mass values, or

volumes were raised, and discussed fully. The impact of this brief experience and the

reaction of her class led her and a colleague to pursue this apporach further in the unit;

one obvious result was the increased mental activity by the classes during the unit. The

class achievements were improved on previous years, but whether this was due to better

learning or better students was not clear. Certainly these teachers are determined to

trial a similar strategy next year but be more formal and meticulous in their record

keeping.

4. Group Work in Chemistry

Two teachers, who usually set assignments and learning activities that are directed

at individuals in a class, wished to explore the value of small group work in Chemistry.

This technique had been used in some practical activities but not in other class tasks.

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The teachers were interested to see what responsibilities the groups of students

accepted, and the strategies they adopted.

DISC U SSIO N

Although the motives for enrolling in the course were varied, all the teachers

appreciated the opportunity to meet with colleagues who were also interested in helping

their students learn. So far, half the teachers have decided on particular strategies to be

used in their classes, at least in part icular topics. But during the course itself, and in the

intervening two months some cri t ical issues have arisen and are as yet unresolved.

The first of these relates to why any teacher should be involved in the first place.

The fact that teachers are prepared to corn mit t ime and money, possibly without their

principals being aware of this commitment , for professional development is admirable.

Unlike many countries New Zealand has been slow to develop appropriate post-graduate

courses for teachers. Fortunately links between Colleges of Education, Polytechnical

Colleges and Universities are growing stronger. Courses in Maths Education which are

joint courses of the College of Education and the University, have recently been

approved as an example, but equivalent courses in Science education should be seen as a

priority in all main centres.

The second issue relates to the procedures of assessment within New Zealand in the

Senior school. At present there are mainly external examinations at the end of Forms 5

and 7 (Years I0 and 12), with Sixth Form Certificate, SFC, internally assessed. A school

has a pool of grades to be allocated to SFC, from their students' performance in School

Certificate, Form 5. The anomaly is this: despite the decision and competence of a

particular teacher in a particular class at Form 6, at present that teacher still has a

particular set of grades available to allocate to her/his students. Thus teachers and

students who work conscientiously to improve the students ability to learn independently,

and effectively may never see that improvement acknowledged publicly. Fortunately,

there are currently some trials of stand-alone moderation at SFC.

Finally, one of the important factors determining the success of PEEL was the

regular meetings, and the group support that developed. In a similar way, it is vital for

continued morale, evaluation and professional development that this group meets again

and this is planned. It is also pleasing to see that four of the group will present their

developments at the 1988 NZ Science Teachers Association Conference. One key

objective, that of raising the confidence of teachers to describe their innovations to

fellow professionals, is being realised.

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REFERENCES

BAIRD, J.R. & MITCHELL, LJ. (eds.) (1986) Improving the Quality of Teaching and Learning: An Australian Case Study - the PEEL project. Melbourne, Monash University Printery.

BAIRD, J.R. MITCHELL, I.J. & NORTHFIELD, J.R. (1987) Teachers as Researchers: the Rationale; the Reality. Research in Science Education, 17, 129-138.

BLOOM, B. (1984) The 2 Sigma Problem: The Search for methods of group instruction as Effective as One-to-One Tutoring, Educational Research, June/July, 4-15.

BURNS, J.R. (1982) An Evaluation of 6th and 7th Form Chemistry in terms of the needs of the Students and the Corn munity, Report to the Department of Education, Wellington.

CARR, M. (1984) Model Confusion in Chemistry, Research in Science Education, 14, 97- 103.

FENSHAM, P.J. (1984) Selective Cueing Among Chemistry Teachers, Research in Science Education, 14, 146-156.

JOHNSTONE, A.H., MORRISON, T.I. & SHARP, D. (1971) Topic Difficulties in Chemistry, Education in Chemistry 8, 212-3, 218.

LARKIN, J.H, & REIF, F. (1979) Understanding and Teaching Problem-Solving in Physics, European Journal of Science Education, I, 2, 191-203.