MAPPING INDIVIDUAL-PERFORMANCE OVER TIME

Cross-sectional research investigating seniority, tenure, and age as they relate to job performance has demonstrated an initial positive linear increase followed by a plateau. Investigations into the stability of performance have demonstrated that individuals change their rank order over time. Taken together, these findings suggest that the curvilinear relationship displayed in the seniority, tenure, and age research is actually made up of many different intraindividual change patterns. Performance data for two samples of professional baseball players were used to investigate these individual change patterns for systematic and meaningful differences. The results demonstrated the importance of studying performance over time at the individual level and that focusing on either mean performance or change in rank order can mask systematic individual patterns of change.