Diagnosing fictional diseases: age and variability of training content in concept formation

This experiment had two purposes: investigation of the effect of variability in the content used during training on concept learning, retention, and transfer and the extent to which this training manipulation interacts with age. Participants were 27 older adults (M = 68.2 yr., SD = 7.4) and 54 younger adults (M = 20.6 yr., SD = 4.0) who were asked to learn an imaginary disease by reviewing the symptoms of fictional patients. Participants were assigned to one of two variability groups in training, which were defined by how much patient cases resembled each other. Dependent measures were classification accuracy over eight blocks of training, followed by retention and transfer ("diagnosing new patients") two days later. Analysis of variance yielded only one significant interaction of age and training variability (on retention), but none of the paired comparisons were significantly different. There were no main effects of training group on any dependent variable.