The study was aimed at establishing a method of symbolic mediation of actions in an experimental procedure simulating a classroom situation. The focus of the method was making sure that the position - a method of perception - should not be reduced to the rule, in order that the method itself would be singled out as a specific reality and would preserve its meaning as a specific subject of actions and discussions. The experimental model included two types of mediation: the position and artificial notions denoting positional actions of the child and the adult. Experimental findings show that "thinking situations" as different from situations of rule-oriented actions emerge in specific conditions - when construction of a position is linked to understanding the meaning of the action. As a result the child's sphere of the meaningful expands: in the actions of another person (an adult) he/she begins to see not only the pattern and the result, but also a position, a point of view.