Level 1-3: Sampling and Recruiting Participants

A study is only as trustworthy as the people in it. This level is about whom you include, how you reach them, and why those choices make or break your findings. You will learn the sampling strategies that keep a study honest and generalisable, and the recruitment tactics that work in real low- and middle-income country settings.

Who this level is for

Anyone planning to collect data from people: researchers, clinicians, study coordinators, monitoring-and-evaluation and program staff at any level, and curious learners from other fields. No statistics background needed. Recommended after Levels 1-2.

What you'll learn

• The difference between a population, a sample, and a sampling method
• How target, accessible and actual study populations relate to one another
• How selection shapes internal validity and how far your results generalise
• How to write clear, defensible inclusion and exclusion criteria
• Probability and non-probability sampling methods, and when each is realistic and acceptable
• Practical, ethical strategies to recruit and retain participants despite refusals, stigma and logistics

You finish with: Your sampling strategy + recruitment plan.