Fem elevers föreställningar om organsystem: vad händer i kroppen när vi dricker vatten?

It has earlier been shown on a group level that it is difficult for 9th grade students (15-16 years old) in a Swedish school to understand how water is transported in the human body. The detailed analysis of five Swedish students in the 9th and final year of compulsory school concerning their ideas about water transportation is presented here. The empirical data consists of drawings, answers to a questionnaire with both open ended and multiple-choice questions, and student interviews. The analysis shows that all the students struggle to produce explanations involving the three organ systems: digestive, blood and excretion systems and they seem to use a variety of explanatory models as basis for their reasoning. Possible ways of understanding this are discussed together with implications for future teaching