Final answer:
Longitudinal and Cross-Sectional Studies are important research strategies to understand human development.
Step-by-step explanation:
The two research strategies that are particularly important to understand how people develop are Longitudinal and Cross-Sectional Studies.
Longitudinal studies involve following a group of research participants for an extended period of time to observe changes that occur over time. This method allows researchers to study developmental patterns and collect data on how individuals change mentally and physically.
Cross-sectional studies, on the other hand, involve comparing multiple segments of a population at a single time. This method can provide insights into different age groups and help identify differences or similarities in development across various stages.