us that sometimes the review is more meaningful if there are slight changes in method or point of view; this is of interest in our study because the sleep-learning investigations report better results when the material is not changed. The recommendations to study before going to sleep are modified by Weinland, "unless physically or mentally overtired." He also recommends, on the basis of several studies, learning the material in the evening before going to bed, and reviewing it the next morning. He too values overlearning, but feels it should be used with discretion. And he notes that miscellaneous items can best be remembered by finding a pattern or principle for it: a pattern in the spelling or in the arrangement of numbers, in features and appearance and behavior of people, in the rhythm and melody of music, in the customs of a group, and in suffixes in language; a principle of spelling or grammar rules, a principle behind group customs which presents them in a unified way— and so forth. Rhyme, numbering, alphabetical order, abbreviation, a kind of acrostic system of making words out of first letters of a series of facts, pigeonholing (Simonides Spatial Arrangement), translation of numbers and letters already referred to, paired associates and chain associations (also referred to above) are all mentioned by Weinland as memory devices that have some value but also limitations. Numbering ceases to be useful when large numbers of items are to be considered; alphabetical order may result in blocking; abbreviation can be confusing, or even come before remembering the whole