maintenance of expertise. Focussed deliberate practice at the acquisition stage contributes to cognitive or physiological gains that enable transitions across a sequence of states relevant to expertise. Continuation of such practice contributes to the maintenance of expertise and, together with compensation and adaptation, helps to lessen performance loss beyond the period of peak performance. More specific models include those that emphasize the physiological underpinnings of expertise in different activities, cognitive techniques used to enhance performance, tactics within competitive activities, strategies pertaining to repeated performances, supportive influences on the development and retention of expertise, and statistical modeling of age trends. From a life span perspective, such modeling should take account of three temporal trends that, by consensus, provide the methodological foundations for lifespan research. These trends are historical transition (e.g., in participation rates and types of training in sport), cohort differences (i.e., cross-sectional trend) and age changes (i.e., longitudinal trend). Issues in modeling that require attention include (but are by no means limited to) the following: a) discussion about appropriate data analytic procedures to distinguish developmental and aging effects from those associated with cohort differences and historical era; for example, the extent to which developmental effects can be modelled for use in identifying talent in sport; b) investigation of the generalizability of findings from top performers: for example, the extent to which their age trends generalize to those of lesser ability; c) examination of issues related to attrition from databases of top performances: for example, attrition from such databases as age-class records and annual ‘Top N’ performance rankings arise from deletion of entries replaced by superior subsequent performances, in addition to reasons associated with morbidity, mortality, and loss of interest. |