Types of Developmental Research Designs

Cross-sectional Design

A cross-sectional study compares the behaviors of different age groups at a single time point.

most common in developmental research

less time-consuming and less expensive than the other methods

Longitudinal Design

examine the same individuals over a period of time; regular intervals

Longitudinal research takes time. Sometimes people quit before it ends. This is called attrition. Researchers should start with larger samples as people will leave. But some groups may leave more than others. For example, people who are sick, poor, or less educated may quit more. This can make the results less accurate because the people who stay are not representative of the whole population.

takes a long time

Sequential Design

include elements of both cross-sectional and longitudinal studies 


focuses on the lived experience of people, usually as detailed by the research participants (also called “informants”) and as observed by the researcher relies heavily on participant observation

Cohort Design

longitudinal study in which researchers monitor and observe a chosen population over an extended period of time, with no particular aim

Case study


Survey and Interview


Ethical Issues in Developmental Research

Informed Consent Protection of individuals’ rights Right to withdrawal Debriefing Confidentiality Deception