Learning as Dynamic Function of Habit Strength and Field-structure

According to Lewin (3), from the view point of field-theory 'any behavior or any other change in a psychological field depends only upon the psychological field at that time ........ This statment has been frequently misunderstood and interpreted to mean that field theorists are not interested in historical problems or in the effect of previous experiences.' So he elaborately discussed the structure of the field at a given time. Psychological field as well as physical field is composed of not only space but also of time. Briefly, it is of time-space units. So the psychological field at that time has a time-range, that can be of the order of seconds, minutes, days, months or years. But if this is true, then what does learning mean? According to Lewin (4), learning is a change in cognitive structure. From this statement arises then the question, if a cognitive change takes place in the time-space field, by what can we know where and when such a change has taken place? Because the field as a continuous and congnitive structure is built up in the organism not in the external field, so we cannot observe a change in cognitive structure, unless we observe a change of behavior and then operationally define a structural change. To find out a change in cognitive structure we must at first know the cognitive structure preceding the change, and then determine the changed one. Classic expamples are the detour problems.