psychology definition of longitudinal design
A longitudinal design is a research study where a sample of the population is studied at intervals to examine the effects of development. In a longitudinal design, you have a group of people and you study something about them. Then you collect their contact information. After a set amount of time-be it weeks, months or years-the participants are called and asked to return. Tests are re-administered to see what changes are in the participants.
Sociological Research: Designs, Methods. 1  Crossâsectional, in which scientists study a number of individuals of different ages who have the same trait or characteristic of interest at a single time. 2  Longitudinal, in which scientists study the same individuals or society repeatedly over a specified period of time.