PROBLEMS IN PSYCHOLOGICAL CHANGE OVER TIM E

The analysis of change in characteristics of individuals over time is stymied by various problems: 1.) the imprecise measurement of change w ith the difference score, 2.) distortion of relationships between the change and other variables due to the errors of measurement, 3.) unequ al possible changes in individuals with different initial scores, 4.) ambiguity of the concept of change extent. The paper Is an introductio n to these problems requiring no preliminary statistical and psychomet ric knowledge.