ABSTRACT
The Montreal Institute has a strong Piagetian background due to the common language and to an exchange of staff members. In this it holds a unique position on the American continent. Jean Claude Lasry selected an experimental group and a control group by means of a pretest. The pretests consisted of inclusion problems as standardized by Pinard and Laurendeau for French-Canadian children. As a criterion of his operational level each child had to respond correctly from the very first moment and justify all his or her answers with operational arguments. Children who spontaneously corrected their originally wrong answer while justifying the right one were also considered to be at the operational level. Lasry's experimental children showed very little transfer ability to five more or less related tasks. He just chose several Piagetian problems that might very well be related to the inclusion problem.
