Effect of Changes in the Time Variables in Memorizing, Together with Some Discussion of the Technique of Memory Experimentation

The effect of changes in the different rate variables in memorizing has been the subject for occasional investigation in the Psychological Laboratory of Indiana University since I894-5, beginning at that time with the preparation of a Master's thesis by Supt. Sanders on the effect of different rates of reading lists of associable and dyssociable words and letters upon their retention and reproduction by auditors. The following year, with a view to extending the investigation to impressions received through the eye, and with a view also to securing apparatus of general utility for memory experiments, the writer designed the compound interrupter and exposure drum, figured and described further on. With this apparatus several studies were begun at different times, but none completed till Supt. Herrington made use of it in the preparation of a Master's thesis, in I903-4, dealing with the effect of varying, in the learning of nonsense syllables, the duration of exposure of each syllable, the intervals between syllables, and the intermission between readings of series of syllables. The points of special interest in the investigation have been partly technical and psychological and partly educational. The study of the rate variables in memorizing is, of course, a direct study of certain elements in the technique of experimentation in this field. To avoid the possible disturbing influence of these elements, experimenters have usually endeavored to keep them constant throughout an investigation; the study of their effects should reveal the significance of variations in them and also under what conditions the best experimental results may be expected. The apparatus required must not simply be serviceable for ordinary experimentation, but must, in addition, be adjustable with regard to the variables to be studied, so that what will serve for this purpose will serve for most, if not all, others in which comparable materials and methods are employed.