Abstract
The project pupils work on problems with a goal which cannot be reached
("invisible wall project") analyses problem solving processes of children in
grades 3-4 and 7-8. So far, we have described basic components of problem
solving abilities by using interpretive methods. We now want to apply
statistical methods, e.g., for comparing abilities of younger/older children.
Consequently, we have complemented the qualitative interpretive methods by
quantitative methods. The paper describes the methodological background of
both sides of the project.