Discussion

Here several issues are discussed: the difficulty and importance of going “beyond appearances”; the need for very good basic teaching pre-16; the importance of developing mathematical skills and the possibilities for future research.

Going “Beyond Appearances”

The report is entitled “Beyond Appearances” because that is how chemists approach the world: in terms of the unseen particles making up substances we need and use everyday. This is so instinctive to a chemist that s/he cannot “not see” particles. A professional chemist I met recently showed me his PhD thesis, which described how he personally had created a new class of compounds by making over eighty new organometallic molecules. These were his work, his life, his obsession. School students cannot share this obsession because they do not possess “molecular spectacles”. Similar arguments apply to understanding energy - “seeing” this dissipated into non-useful forms is a key to accepting the First Law of Thermodynamics. These points are fundamental to genuine understanding of chemistry, but as this review indicates, are problematic and, I believe, have consequences for our subject which are seriously underestimated. When students cannot “see” particles they cannot really understand chemical reactions and so the fabric of chemistry is lost to them in a haze of impenetrable events completely at odds with their every day experiences of a “continuous” world. Perhaps the best many students can hope for is that their teacher presents the subject in a relatively interesting way permitting learning of some facts and patterns of chemical behaviour. Although this generates some professional chemists to supply our needs for the future, many students express dissatisfaction with the subject as Osborne’s and Collins’ (2000) recent report suggests. Action is required.

Develop sound and consistent pre-16 chemistry teaching

A number of references have been made to pre-16 teaching strategies on chemical learning. Two major points can be made. First, delivery of the National Curriculum requirements is a prime goal for UK pre-16 teachers, so what is presented in chemistry lessons reflects the prescribed content. Hence, many of the comments about how we teach these topics in pre-16 courses apply to us all. I also taught lessons involving students compiling a table comparing the boiling points and structures of covalent and ionic compounds and teaching ionic bonds in potentially unhelpful ways. However, second, we must take account of the misconceptions research and move on to new approaches. The remainder of the discussion sets out what this might mean.

The evidence indicates that one reason for the impact of current pre-16 teaching is that students find it very difficult to “unlearn” an idea. There are many references throughout this report which suggest that students’ earliest experiences of chemistry have very significant and far-reaching effects, often influencing at least their work at A level. Taber (1997a) reflected on this, noting that students never seem to dismantle old ideas about chemical bonding, but instead prefer to add new thinking. We also see evidence for this in learning about fuels and hydrogen bonding. Of course, for many students this results in confusion and poor understanding. The challenge for teachers is therefore to develop ways of teaching the very basic principles, particle theory and chemical change very well. By “very well” I mean in ways which do not “skim the surface” of students’ thinking, but provide intellectual challenge to help develop the “molecular spectacles” needed for further study. If students cannot “unlearn” ideas, then we should teach the chemistry we really mean them to know right from the beginning. The compromise of the current “soft-sell” position is proving to be fruitless.

Developing mathematical skills

Chemical concepts seem to divide neatly into those referred to as “qualitative” and “quantitative”. “Qualitative” concepts are those which do not require additional skills from outside the subject, particularly mathematics. In this category are particle theory, changes of state, chemical change, (including acids and bases and elements, compounds and mixtures) and chemical bonding. These can be taught without mathematical skills. “Quantitative” concepts use higher order maths skills such as proportion and ratios, logarithms and probability. Besides teaching the basic qualitative concepts well, students also need the necessary skills from outside chemistry to cope with the extra demands made by the quantitative areas.

Possible future research

This report reveals that certain concept areas have received extensive treatment from researchers, while others are relatively unexplored and still others, such as aspects of inorganic and organic chemistry are untouched. “Stamp-collecting” of misconceptions in these areas is required. Second, in order to improve our current teaching, there is a need to establish in much greater detail what teachers actually do in teaching these ideas. We can do much more to share these, develop them and help new teachers learn them. Thirdly, further work on developing diagnostic tests to help determine student progress in learning would be useful. Several references have been made above to tests developed by researchers. Their value lies in heightening teachers’ awareness of problems in learning, so helping prevent “surface skimming” and instead maintaining intellectually challenging work. Embedding these in every day practice could be beneficial.

This report comprises an extensive review of misconceptions research in chemistry coupled with my personal views about the implications these have for teaching and suggestions for progress. I hope readers have been challenged to consider how we can implement the necessary changes to help more students go “Beyond Appearances”.