Summary

In this study session you have learned that:

1. Defining the study population and study variables, and choosing the study type, are an essential starting point for every research project.
2. The way you define your study population depends on the problem you want to investigate and on the objectives of your study.
3. Variables may be numerical or non-numerical, so the data collected may be quantitative or qualitative, and this determines the appropriate method of analysing the data.
4. Study designs may be observational or experimental. Observational studies involve making observations. Experimental studies involve modifying or changing something about the study participants and looking at the effect of this intervention.
5. The three common observational study designs are cross-sectional, case-control and cohort studies, all of which involve a survey of some kind.