Individual and age differences in block-by-block dynamics of category learning strategies

The present experiment examined individual and age differences in the dynamics of category learning strategies. Participants learned categories determined by a disjunctive rule with relational features through a feedback training procedure. During training, participants responded to strategy probes following each block to provide online assessment of the extent to which rule- and exemplar-based strategies were used throughout the training period. We introduced this measure as an alternative to model-based approaches to assessing individual differences in strategy use during training. Following training, participants classified ambiguous transfer objects that were assumed to distinguish between earlier use of rule- and exemplar-based learning strategies. We included this measure to obtain a relatively objective index of strategy use during training. Next, participants provided global ratings of their use of rule- and exemplar-based strategies during training. Results showed that strategy preferences expressed on the final training block predicted categorisation of ambiguous transfer objects better than global strategy reports. In addition, we utilised the block-by-block strategy reports to investigate the dynamics of learners' strategy preferences over the course of training. The findings revealed greater fluidity in strategy preferences for both younger and older adults than has been previously documented in the category learning literature. The novel block-by-block strategy reports in conjunction with the transfer-based approach allowed for a more nuanced examination of individual and age differences in strategy use and categorisation performance.