When a scientific knowledge is
presented to them in class, they synthesize this knowledge with their previous assumptions and develop their
new models. As the learning proceeds, the students modify this new model they synthesize gradually in a way
that it can contain more scientific concepts. The teachers’ mission is to lead the students’ naive and initial
models in such a manner that they will contain more scientific concepts. This situation requires presenting
platforms for discussion to students and determining their present mental models instead of making them go
through compulsory experiences that aim to teach only scientific knowledge. Determining students’ present
mental models will give teachers useful information in preparing a basis for them to structure knowledge as
desired by knowing whether their present knowledge is correct or not.