Subjective Structures and Operations in Semantic Memory

Relations of semantic distance to response latencies in similarity judgments, to reaction times in a same-different classification task, and to proximity of recall in a free recall task were investigated. A multidimensional analysis of the similarity judgments was used to determine semantic structure and distances for pairs of animal words chosen from three classes: mammals, birds, and jish. A four-dimensional structure revealed both the class and quantitative contributions to the similarity ratings. Semantic distances were directly related to response latencies for words from the same class and inversely related for words from different classes. Distances were also related to reaction times for “same” judgments in the classification task, but not for “different” judgments. Independent ratings of typicality did not improve the relationship. Semantic distance was also a good predictor of proximity of recall for mammals, less so for birds, and not at all for fish.