A research strategy for investigating group differences in a cognitive construct: Application to ageing and executive processes

A strategy involving five distinct phases is proposed as a means of obtaining the most informative evidence about group differences in a particular aspect of cognitive functioning. Perhaps because the phases require different types of analytical methods, most prior research has focused on only a few of the proposed phases. This is unfortunate because each phase provides valuable information about the nature of the relevant construct, and its role in group differences in cognition. The strategy is illustrated with research on adult age differences in executive processes.