Maximise Research Impact with Diverse Sampling Strategies: How and Why to Increase Diversity in Samples

What is sampling in research?

Sampling is one of the first stages of a research study. It means deciding the group you will collect data from in your research. Sampling is used to study a smaller portion of the population to make generalisable claims about the larger population.¹ The extent to which the claims are generalisable or “valid” depends on having a good sampling strategy. The specific sampling strategies varies, depending on the aims and type of research (quantitative, qualitative).

Crafting a winning sampling strategy

When designing a sampling strategy, researchers already have a research question in mind and a plan of how the study should be executed. The goal may be to explore a phenomenon (inductive) or to test an existing theory (deductive). This plan may include quantitative or qualitative research methods.

The sampling strategy will be informed by these aims and objectives. Quantitative studies tend to prioritise having a large sample size or use a “random sampling” method to ensure validity and generalisability.¹ Qualitative research tends to have smaller samples and use a more “purposive,” non-probabilistic (not random) approach. This involves selecting specific participants who can provide rich information to address the aims and objectives of the research.¹

Importance and the benefits of encouraging diversity in sampling

Regardless of which sampling method is used, a good sampling strategy encourages diversity to ensure research findings are valid, reliable, and generalisable. For example, a clinical trial to test a drug intended to be used on the general population would need to include a very large and diverse sample to account for all demographics. As certain subgroups of patients may respond differently to interventions, a non-diversified sample could mean that the results of the trial are not valid (drug is not safe/not effective) for the entire population.

Diversity is also important for smaller qualitative studies. “Maximum variation” sampling in qualitative research aims to recruit participants who are widely different from each other to obtain as many diverse perspectives as possible.¹ While diversity in sampling within quantitative studies helps ensure validity and generalisability, diversity in qualitative studies supports researchers to capture a wide range of different perspectives, creating more inclusive and representative research findings. This is particularly important for minimising inequalities in healthcare research, as certain hard-to-reach or underprivileged populations often miss out on opportunities resulting from research outcomes.

Maximising Positive Impact

Beyond conducting “good” research (research that is valid, generalisable, and reliable), a key goal is to produce as much of a positive impact on the world as possible. Ensuring diversity in sampling helps researchers reach and take into consideration the voices of those who are normally marginalised and underprivileged. By actively encouraging a diverse sample that includes minority voices, researchers can produce a better impact on society through equitable, inclusive, and representative research.

References

1. Given, L. M. (Ed.). (2008). The Sage encyclopedia of qualitative research methods. Sage publications.