Age differences in learning and the question of preexperimental interference

Although previous research has revealed a consistent finding of an interaction between age and incongruent information, the exact cause of this age difference in relation to preexperimental interference has not been identified due to methodological oversights in the existing literature. That is, it is unclear whether the cause of the age difference in learning is the incongruity of the new information with prior knowledge or simply the amount of new information that is presented. To overcome previous problems, this study separated the effects of congruity and amount of new information. The participants consisted of 50 older and 50 younger adults who possessed varied levels of familiarity with a standard keyboard as determined by a pretest. Participants were then presented with a new keyboard format (Dvorak) and performed three typing trials. The results revealed a significant main effect for age, such that the older participants performed worse than the younger participants on the new keyboard. However, there was no interaction between familiarity and age. This study provides support for Welford's (1958) theory that it is the amount of the new information and not the preexperimental interference that accounts for the age difference in le arning.