The single-link cluster method is used to construct a hierarchic classification for the 1400 documents in the Cranfield test collection. A variety of retrieval strategies applied to this hierarchy are evaluated in terms of effectiveness and efficiency. (Author)

Study 1 asked second through sixth graders, who could answer inclusion questions, to answer such questions without empirical information about relative quantity and to predict whether subordinate classes could be made larger than their superordinate classes. In study 2, children's performance in two part-whole domains, classes and collections, was…

Seventy-two first grade students and 72 freshman college students participated in a study designed to test the hypothesis that the younger the child, the more perceptible are the attributes used in judging equivalence in sorting tasks. (BD)

This study was designed to contrast children's recall clustering before and after they acquired stable input organizations. A sample of 120 subjects (24 from preschool grades, 1, 4, 7, and college) performed two successively presented, procedurally identical, series of recall-sort-recall tasks. (Author/JMB)