Educational Problems in Writing Chemical Formulae and Equations

Howe, T. V (1975) Educational Problems in Writing Chemical Formulae and Equations. MSc(R) thesis, University of Glasgow.

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The difficulties existing for many pupils in the areas of formulae and equations and the belief that many of these problems were due to maturity barriers, led to the inauguration of this study in 1970. A preliminary survey was made of the situation extant in 1970 concerning these topics. This revealed a very confused picture with wide variation of teacher approach. The most obvious problem was one of over-complexity in formulae and equations. Teachers were teaching with little or no regard for the developmental ideas of Piaget et al. This problem was investigated at school level by a test based on a Gagne net for the writing of formulae and by a questionnaire. This test was examined in depth and confirmed the indications gathered in the preliminary survey. Pupils did not appear to reason logically when writing formulae but rather committed certain common formulae to memory, and failure at one step in the thought process did not appear to affect performance in the next. The very high number of pupils unable to handle proportion (71%) calculations from equations (97%) was disturbing, (the problem may be purely mathematical,) and many pupils showed a lack of understanding of even the most basic principles e.g. nomenclature, formation,of ions. Pupils seemed able to cope with individual steps in e. g. formula writing, but could not handle all the material "en bloc" when it was presented in a very short time (2-3 months). This meant that overall performance was very poor (28% correct). A re-run of part of this test confirmed these results. The questionnaire revealed that pupils tended to underestimate the difficulty of many topics and that teachers were more consistent than them in their estimates of difficulty. The teaching order of the 'O' grade course in Chemistry was then examined in the light of the degree of complexity in formulae and equations needed for each section. A revised teaching order, which was basically 'organic first' was drawn up using the principle of gradual revelation of these topics. To evaluate this revised order a maturity study was set up, having both experimental and control groups. The progress of the groups was monitored by a series of short tests, the results of which, and the 1973 'O' grade examination in Chemistry were analysed. No significant differences were found, but following the revised order did not disadvantage pupils over those following the standard orders. In fact there was some evidence to show that the revised order had achieved for these pupils, a higher level of understanding on the more difficult topics, especially calculations from equations and the mole. They also were more consistent in their level of performance on writing formulae. A detailed analysis of the last test (an overall revision of the work) was carried out and showed the same problems as were evident in the Gagne study e. g. interpretation of nomenclature such as the difference between - IDE and - ITE compounds. Some topics appeared to be still beyond the majority of pupils e. g. (i) extrapolation from Na2CO3 to Na2SiO3 (12%) (ii) writing balanced equations (20%) (iii) calculations from equations (20%). However pupils did seem to grasp the mathematical rules for formulae writing reasonably competently. A similar questionnaire to that used in the first investigation revealed that in general the revised group found the course easier than the control groups and that pupils now overestimated the difficulty of those topics previously underestimated. A final survey in 1974 showed a situation on the one hand eased by the removal of a recall barrier in formula writing and on the other worsened by the choice of the correct level of complexity of formulae to be used in any questions being left to the pupil. Recommendations were made for lessening the amount of conceptually difficult material (Piaget Stage 3) in the 'O' grade syllabus and its replacement by work involving lower order skills, including purely practical ones.

Item Type: Thesis (MSc(R))
Qualification Level: Masters
Keywords: Science education
Date of Award: 1975
Depositing User: Enlighten Team
Unique ID: glathesis:1975-78689
Copyright: Copyright of this thesis is held by the author.
Date Deposited: 30 Jan 2020 15:02
Last Modified: 30 Jan 2020 15:02

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