Scripts to calculate practice and attrition effects. Examines tests comprising cognitive domains as well as AFQT.

Methods are based on: Ronnlund M, Nyberg L, Backman L, Nilsson LG. Stability, growth, and decline in adult life span development of declarative memory: cross-sectional and longitudinal data from a population-based study. Psychol Aging. 2005;20(1):3-18.

Longitudinal subjects, attriters and attrition replacements are assessed for group differences. Practice effects are examined before and after adjusting for any differences in potentially important measures.