Individual Differences in Learning and Transfer: Stable Tendencies for Learning Exemplars versus Abstracting Rules
We hypothesize that during training some learners may focus on acquiring the particular exemplars and responses associated with the exemplars (termed exemplar learners), whereas other learners attempt to abstract underlying regularities reflected in the particular exemplars linked to an appropriate response (termed rule learners). Supporting this distinction, after training (on a function-learning task), participants either displayed an extrapolation profile reflecting acquisition of the trained cue-criterion associations (exemplar learners) or abstraction of the function rule (rule learners; Studies 1a and 1b). Further, working memory capacity (measured by Ospan) was associated with the tendency to rely on rule versus exemplar processes. Studies 1c and 2 examined the persistence of these learning tendencies on several categorization tasks. Study 1c showed that rule learners were more likely than exemplar learners (indexed a priori by extrapolation profiles) to resist using idiosyncratic features (exemplar similarity) in generalization (transfer) of the trained category. Study 2 showed that the rule learners but not the exemplar learners performed well on a novel categorization task (transfer) after training on an abstract coherent category. These patterns suggest that in complex conceptual tasks, (a) individuals tend to either focus on exemplars during learning or on extracting some abstraction of the concept, (b) this tendency might be a relatively stable characteristic of the individual, and (c) transfer patterns are determined by that tendency.
In the concept learning and problem solving literatures, individual differences, though implicitly assumed, have not received extensive empirical or theoretical attention. In the concept-problem literature, a few researchers have attempted to identify qualitative differences across individuals in what is learned during training. In one seminal study, Medin, Altom, and Murphy (1984) trained participants to learn to categorize instances from an ill-defined category. Based on the training performances and classification of new instances, Medin et al. suggested that some learners had abstracted a prototype during training, whereas others had learned particular exemplar—category associations to represent the ill-defined category. In a more complicated category learning paradigm, Erickson (2008) required subjects to learn to classify stimuli into four categories, with two categories determined by a single dimension and two categories determined by two dimensions. Subjects’ responses indicated that individuals differed in what they had learned, with one group appearing to acquire a single category bound (one overarching representation) to map the four categories, whereas another group had partitioned the space into two bounds (one for one pair of categories and one for the other pair of categories).
