Prevalence Study: This is similar to cross-sectional studies but specifically measures the total number of cases (prevalence) of a disease or condition in a population at a specific point in time.
Correlational Study:A type of non-experimental research method which involves observing two variables to determine if there is any relationship between them. It can be part of cross-sectional studies when looking for correlations among variables at one point in time.
Population Sample: The group selected for participation in an experiment or study. It should ideally represent the larger population from which it was drawn.