There is running a great educational reform in the Czech Republic which aim is to change curriculum, main goals of education and teachers approach. The main goal of our education is no more passing the knowledge on the pupils but the teachers should show to the pupils the way to the life-long learning. Instead of lot of encyclopedic knowledge the children should have skills to solve problem, to communicate, the social and working skills,… (Rámcový, 2005). The most suitable approach to teach these skills should be the constructivist one. This contribution is a part outcome of my dissertation where I want to find out if the teacher's concept of schooling influences the time the pupils are able to keep the taught topic in mind. In the contribution I will show the method of collecting data about the teacher's concept of schooling.I was observing 16 teachers in the third class of primary school in the science lesson. The observation was focused on whether the teachers used the constructivist approach during the lessons. The constructivist approach was operationalized as 18 characteristics, which were compiled by Elizabeth Murphy (1997). The children drew three times the same picture as an answer to the question "Where does the food go through a body?" The children had an outline of the human body on the paper with the question to help those who did not draw well. The first drawing was done at the moment they had learnt nothing yet about the digestive system at school. Then in the observed lesson the children were taught about the digestive system and asked to draw the picture with the same question. We could see the difference between the first image of the problem and then the situation after the lesson, where they should have learnt, how it exactly works. In three months they drew the picture once again. This method showed how the preconceptions changed.The analysis of the data about teacher's concept of schooling will show us which characteristics of constructivist approach are used in the lesson and how does it influence the quality of children's conceptions.KORCOVÁ, Kate?ina. Development of the Preconception of the Primary School Pupils: Experience with the Research up to Now. In Education-Line database. Leeds: University of Leeds, 2006,. 13 s. URL MURPHY, Elizabeth. Constructivist checklist. [online], Constructivismus, 1997, [6.3.2006]. World Wide Web: . NOVOTNÝ, Petr: Výukový proces z pohledu sou?asné školní didaktiky. Novotný, P. - Pol, M. (eds.) Vybrané kapitoly ze školní didaktiky. Brno: Masarykova univerzita, 2002. p. 17 - 28. ISBN 80-210-3020-8. Rámcový vzd?lávací program pro základní vzd?lávání. Praha: Výzkumný ústav pedagogický v Praze, 2005. ISBN 80-8700-002-1. REICH, Kersten. Konstruktivistische Didaktik. Weinheim: BELTZ, 2004. ISBN 3-407-25383-4. REISS, Michael J. - TUNNICLIFFE, Sue Dale. Students´Undestandings of Human Organs and Organ Systems. Research in Science Education, 2001, Nr. 31, p. 383 - 399.