Number of alternatives and similarity in verbal-discrimination learning

Abstract

Lists of 16 two-alternative (2-A) or four-alternative (4-A) verbal-discrimination items of either low similarity (LS), high within-item similarity (WIS), or high between-item similarity (BIS) were learned by 144 S s. When biases that favored 2-A lists were removed, fewer errors occurred in learning 4-A lists than 2-A lists. More errors occurred in BIS than LS lists with WIS producing an intermediate number of errors. Recognition and recall measures taken after learning revealed better retention of incorrect alternatives from 2-A lists than from 4-A lists, and better retention of WIS items than of BIS or LS items. The results were interpreted in terms of a frequency theory of verbal-discrimination learning.