Final answer:
Longitudinal research analyzes the cognitive development of the same individuals over time, repeatedly gathering data from the same group to observe changes and developments.
Step-by-step explanation:
Research that analyzes the cognitive development of the same individuals as they develop over the years is called longitudinal research. This type of research involves following a group of research participants for an extended period of time and is particularly useful in developmental psychology. During longitudinal research, data-gathering is administered repeatedly over an extended period of time to the same individuals. This approach enables researchers to see how people change and develop over time, making it a powerful tool for studying human development across the lifespan.
In contrast, cross-sectional research compares multiple segments of the population at the same time but cannot reveal how individuals change over time. Case studies focus on an in-depth understanding of an individual or a small group over time but may lack generalizability. Both longitudinal and cross-sectional studies are part of the broader category of observational studies, which include other research methods like naturalistic observations and surveys.