Developmental science rests on describing, explaining, and optimizing intraindividual changes and, hence, empirically requires longitudinal research. Problems of missing data arise in most longitudinal studies, thus creating challenges for interpreting the substance and structure of intraindividual change. Using a sample of reports of longitudinal…

Explored applicability of the Loevinger conception of ego development for early adolescence and developed a measure of earliest ego levels: Sentence Completion Test for Children and Youth. Found oral administration of test did not yield essentially different responses or significantly differing ego-level scores from the written version, regardless…