The aim of this study is to explain the heuristics that are effective in science teacher candidates’ decision making processes related to the ranking of the compounds according to their solubility based on the ten heuristics model proposed by Talanquer. In this study, in which the phenomenographic research method was used, in order to collect data, interviews were conducted with 30 pre-service science teachers enrolled Firat University Faculty of Education Science Teaching Program in the spring semester of 2018-2019 academic year. In the interviews, the participants were asked to answer a question about the ranking of the compounds according to their solubility and explain the reasons for their answers. As a result of the research, it has been determined that all heuristics except fluency heuristic affect the comments and reasoning of the participants, and because of the effects of these heuristics, students generally used shortcut strategies instead of scientific reasoning. Seven different answer patterns were obtained from the responses given by the participants to the relevant question, and the ratio of the answer pattern containing the correct answer is 10 %. It was revealed by the present study that the most used heuristics are the associative activation and attribute substitution heuristics. It was also revealed that although it is not included in the model proposed by Talanquer, the periodic trend heuristic also affects the reasoning of the participants reasoning related to the ranking of the compounds according to their solubility.
Science Education, Solubility, Heuristic, Chemical Education, Reasoning.