Various approaches to the problem of computer modelling of assimilation and forgetting of the educational information are considered. With the help of the multi-component model the Ebbinghaus' curve of forgetting of poorly assimilating information to be remembered through recurrences is confirmed. It is taken into account, that while training there is a transition of weak (poor) knowledge into strong (firm) knowledge, and while forgetting--the return transition of strong knowledge into weak knowledge. Also the model of assimilation and forgetting of the educational material with a high links degree, consisting of information blocks which contain the connected concepts is created. It allows to explain that: 1) while training there is the sharp increase of the understanding level of the studied problem; 2) after termination (ending) of training during some time the level of the pupil's knowledge remains high, and then slowly lowers because of gradual forgetting of the separate learning material elements. The paper shows that the processes of assimilation and forgetting occur according to the logistic law. Along with that the imitating model of training at school which takes into account the knowledge division into three categories and distribution of the educational information on classes is offered. For all cases there are graphs of the knowledge level dependence on time.