Research in memory has been a frustrating task not least because of the intimate familiarity with what we are trying to understand, and partly also because the human cognitive system has developed as an interactive whole; it is difficult to isolate its component modules ??necessary prerequisite for their thorough elucidation. Memory cannot be studied in isolation since it is essentially only an adjunct to the proper execution of our ordinary information processing tasks. In order to try to formulate specifically some of the basic requirements of memory we must therefore examine the structure of the processing tasks for which it is used.
