Two groups of subjects made magnitude estimations of a series of eight circles, each of which had its own color. All subjects received the same number of presentations in both sessions, with half the subjects receiving the same size-color pairing of the first session, and the remaining subjects receiving a different size-color pairing, in the second session, one week later. Interrepetition correlations of exponents for the middle four adjacent presentations were computed. All of the correlations were significantly different from zero with the exception of the intersession correlation of the control group. The control group exhibited a significant decrease in correlation across sessions while the experimental group remained stable. These findings were totally unexpected. A test of difference between intersession correlations was not significant. The results can not easily be explained within the framework of either the response bias or memory hypotheses.

Thomas Marill. / "October 30, 1956." "This report is based on a thesis submitted to the Department of Economics and Social Science, M.I.T., in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Psychology, June 1956." / Bibliography: p. 73. / Army Signal Corps Contract DA36-039-sc-64637 Dept. of the Army Task No. 3-99-06-108 Project No. 3-99-00-100