A study of observational attainment in practical work in school chemistry

Abstract

The research described in this thesis concerns three separate, but interrelated aspects of observation in chemical education at the secondary school level:
a) The effect of different modes of task definition and presentation upon students' observational attainment;
b) The relative effectiveness of different teaching methods, based upon different task presentation modes, upon students' observational competence;
c) The interpretability and interpretation of observational data of different levels of "quality" and "correctness" by students.
These three aspects were examined in three phases of the study, labelled, respectively, the task definition study, the teaching study and the problem-solving study. The latter of these was conducted as £n exploratory investigation only. As a precursor to these,,an investigation into observational threshold values was conducted as a means of determining limits of "observability" of different observational stimuli encountered in school chemistry practical work. The purpose of this was to facilitate the development of "standardised" observational tests for use with 'O'-Level/CSE chemistry students.
In the task definition study, observational attainment was determined under three different conditions of task definition representing no cueing, partial cueing and complete cueing to possible observations. Using fourth-form students as subjects, it was found that an approach based on complete cueing produces a significantly higher observational attainment than the other two approaches, but also produces a significantly higher illusory error rate. Errors of omission are similar for the groups exposed to no cueing or partial cueing only, but for the latter appear significantly higher for non-cued observations than for cued observations.
For the teaching study, a two-term laboratory teaching programme was designed in three different formats based on the-modes of task definition described above. The programme was used with ' three different groups of second-form pupils in three consecutive years. Tests of observational attainment and competence, administered at the end of the two-term leaving phases, showed no significant differences to accrue from the three different treatment formats incorporated in the teaching schemes, although the modes of testing produced differences similar to those found in the task definition study.
Finally, in the problem-solving study, sixth-form students were presented with observational information, concerning qualitative experiments in chemistry, which represented different degrees of completeness. By means of a self-reporting technique, students' behaviour in interpreting this information was examined. The findings from this part of the study are only tentative, but indicate that
(i) students do not acknowledge the limits of interpretability of observational data;
(ii) when faced with information about observations made in sequence, students fail to carry forward interpretations from one stage to the next;
(iii) students are significantly "hindered” in their objectivity in interpretational situations by previously encountered phenomena.