INFORMATION INTEGRATION OF POOLED VERSUS PAIRED SAMPLES

The sample-discrimination procedure asks listeners to identify from wh ich of two possible distributions a given set of samples has been draw n. Typically, discriminability (d' for a single sample) and informatio n integration (inferred from the increase in d' after n samples) are n ot as good as predicted by the observation-integration model. This res earch examined whether information integration could be improved by pr esenting n pairs of samples from the two distributions rather than pre senting all n samples from one distribution then all n samples from th e other (pooling samples). Pooled and paired presentations (n = 1, 2, 3, 4, 5, 6, 8, 12, and 16) were examined for ''easy'' and ''hard'' con ditions (large and small separations between means of the two distribu tions) for both duration discrimination and frequency discrimination. For all four of these conditions, higher d's were always obtained for the pooled presentations. Pairing the samples failed to improve perfor mance and, for the ''hard'' conditions, instead made information integ ration worse. (C) 1995 Acoustical Society of America.