Following the onset of the novel coronavirus disease 2019 (COVID-19) pandemic, daily life significantly changed for the population. Accordingly, researchers interested in examining patterns of change over time may now face discontinuities around the pandemic. Researchers collecting in-person longitudinal data also had to cancel or delay data…

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…

This monograph, the third in a series of four volumes, descibes a study designed to discover and interpret the home conditions under which young children in the English-speaking Caribbean islands, especially the underprivileged, are nurtured. The main purpose of this volume is to document the process by which data have been collected in order to…

Describes issues which are common to all research methodologies and some that were unique to the assessment techniques used in the Child Development Project (CDP) in San Ramon, California. Looks at the limited amount of time given assessments and the "fluid" nature of measurements. Notes that CDP issues involved observations,…