The concept of class positions.. If you select enough for the condition and one practice is the second conclusion of the adequacy of the special and ordinary

Recognize sufficiently well as for the class of situations (same category), any set of positions converged with each other. If selected for the adequacy of the condition and one practice is the second conclusion of the adequacy of the special and ordinary. On the contrary, if the positions were very far apart from each other, do not put the learner in similar circumstances to ensure efficiency. In practice it comes to searching for some positions that are equivalent   Among them. Adequacy example: "Driving a car in the city":

** Positions are Different types of paths, at different moments, in adverse weather conditions Different in different Aktdadat, .... etc..

** Tracks are different Different positions belong to the same class (or family) positions.