Science education research has revealed a number of student mental models for atomic structure, among which, the one based on Bohr's model seems to be the most dominant. The aim of the current study is to investigate the coherence of these models when students apply them for the explanation of a variety of situations. For this purpose, a set of six tasks describing different everyday situations was given to 225 students of the 10th and 11th grades of secondary schools from Northern Greece. Quantitative analysis of the students’ responses using Latent Class Analysis (LCA) showed that there is no consistency between models across the tasks and that the context of the task affects the distribution of students’ responses across models. Qualitative analysis showed a variety of pieces of knowledge from different models that students combine when manipulating the tasks, which possibly causes a lack of consistency within each one of the models. The findings are discussed in terms of between and within model consistency, and the conclusions contribute to the debate concerning the coherentvs.fragmented knowledge hypotheses. The empirical evidence provided by the analysis clearly demonstrates that student mental models for atomic structure were not coherent when applied in different everyday situations. Implications for theory and practice are discussed.

The current study aims to investigate students' representations of the atomic structure in a number of student cohorts with specific characteristics concerning age, grade, class curriculum and some individual differences, such as formal reasoning and field dependence/independence. Two specific task contexts, which were designed in accordance with corresponding teaching contexts for the atomic structure, one based on Bohr's model and the other on the quantum mechanical model, were examined as for their potential to differentiate initial students' representations of the atomic structure (when no specific context was provided). Participants (n= 421) were students of 8th, 10th and 12th grades of secondary schools from Northern Greece. Results showed that, although developmental factors, like formal reasoning, were associated with a better representation of the atomic structure, the task context appeared to have the dominant role, since positive associations were found between student cohort characteristics and representation of the atomic structure in context dependent tasks, even after accounting for the effects of individual differences.

No abstract

No abstract

The present study investigated the association of students’ fundamental ideas and misconceptions about ontological features of atom identity and behavior with the formation of their portrayed representations of the atomic structure. Participants (n = 421) were secondary education students in the eighth, tenth, and twelfth grades. Students’ portrayed representations of the atomic structure were accessed through drawing tasks, while their understanding of the ontological features of atom was measured through a specially designed questionnaire. Latent Class Analysis (LCA), a psychometric method, was applied to the elementary features of the portrayed representations to classify them and test the potential coherence of their representations regarding atomic structure. The LCA revealed three latent classes, which showed a relative coherence in three of the anticipated models, “Particle model,” “Nuclear model,” and “Bohrʼs model.” Moreover, students’ conceptions and misconception about the ontological features of atom were used as covariates in the LCA and their effects on the above-mentioned class-memberships were estimated. Results indicated a significant effect of students’ conceptions of the atomic ontological features on their portrayed representations of the atomic structure. Implications for theory and practice are discussed.