Ratings of the association values on a five-point scale by 95 Ss are reported for the 101 numbers between 0 and 100. The results reveal sizable and relatively consistent differences between numbers which are shown to be related to learning difficulty, as well as a high degree of individual variability. {\textcopyright} 1962.
The Ss were instructed to rate each number as to 'how many different things or ideas are associated with the number, and how difficult it is to think of these associations,' by circling one of five letters (A-E) on a line to the right of each number as presented.