The Invisible Wall Project: Reasoning and Problem Solving Processes of Primary and Lower Secondary Students

The Invisible Wall Project analyzes problem-solving processes of children in Grades 3 and 4 and Grades 8 and 9. The central idea of the research is to use sets of tasks that are all unsolvable, which means they have a goal that cannot be reached. The unsolvability, however, is of a kind that can be understood even by younger children. In our case, the tasks are geometrical puzzles that have to be covered with given tiles. To the unprepared problem solver, the unsolvability is like an “invisible wall” against which the solver bounces in his or her attempt to tackle the task. On the basis of 172 transcribed interviews, we analyze the students' reasoning behavior and compare the nature of the problem-solving processes of primary and lower secondary students.