Abstract
The effectiveness of chemistry education is influenced, among other things, by access to individual representations of chemical phenomena. The theoretical background can be found in Johnstone [1], who divides the representations into: macroscopic, submicroscopic and symbolic.
Effective (chemistry) education involves a balanced amount of transitions between these representations. In addition, tables, graphs, etc. are being used.
The relationship between understanding the chemical phenomena and the representations used to explain them makes the representation competence development an important component of chemistry education [2]. The lack of understanding the representations of chemical phenomena can lead to shaping of so-called didactic formalisms - barriers between the educational content and student's understanding.
The level of work with individual visual representations can be detected using interviews (e.g. Think aloud TA or retrospective think aloud RTA).
However, these methods are burdened by an inaccurate description of the investigator [3]. Therefore, they are often combined with an objective method of eye-tracking, which allows to record the movements of the solver's eyes directly when solving the task [4].
In addition to the intention of the dissertation research, the submitted contribution presents the partial results of the ET study in connection with RTA focusing on students' ability to work with the periodical table of elements. The results show that the reason for the students' failure is ignorance (substitution of the group after the period, or ignorance of the symbols of the elements) and the input misunderstanding due to the inattentive reading.