Introduction

In Study Session 14 you learned some of the basic study designs that you could use to start to do some small-scale health research in your community. In this study session you will learn about the next stages of doing research and why this may be relevant for your work as a Health Extension Practitioner. Of course your research should be able to find out lots of things about your entire community, but studying large numbers of people takes a lot of resources. It uses a lot of time and costs a lot of money. Studying the whole of the population of interest is therefore not usually possible. For this reason, researchers usually study a representative number of the whole population, which is called a sample. To achieve a representative sample for a research study, the people who will be studied (i.e. the subjects) have to be carefully selected using appropriate sampling methods.

In this study session you will learn about different types of sampling methods and how to determine the appropriate sample size (i.e. the number of subjects) needed to generate reliable results from your research. This will help you to extract information from any research on community health and healthcare interventions in your locality.