Method
Sample design is deciding who your participants will be and how many people you need to include.
Purpose
To build a recruitment specification that will help you achieve your research goals.
What you get
A recruitment specification to use to source research participants.
Strengths
- Sample design is a necessary part of the research process, that allows a team to 'control' for the types of participants in their study.
- It helps teams hone their research objectives by being clear about who should be included in the research.
Weaknesses
- Researchers may be unconsciously biased in who they exclude from research. Gender, age, language, income and education levels should all be discussed as part of a sample design.
- It may not be possible to know what or who is important to your research until you get started.
- Complex sample designs can lead to teams being stuck in "analysis paralysis", unconfident of what their data is saying, or who it is saying it about.
Tips
Validity for qualitative research is different from quantitative research. Qualitative studies rarely need more than 40 participants, and as few as 8 participants may yield valid results.
In design research, we usually recruit for experience. For example, we may be interested in people who have registered a vehicle in the past 18 months. We are less interested in ensuring all demographics are represented in that group. If a team thinks that language, age or locale might influence that experience, they should aim for a diverse sample for those attributes.
Toolkits and resources
Updated