How can external validity be strengthened?
• Compile detailed descriptions: In qualitative research, data should generate thick description. Generally, the more detailed the description, the more confidence there is in the applicability of the analysis to wider settings. • Use typical cases: If the study focuses on cases, categories, or settings that are agreed to be typical, there is usually more confidence in the analysis. These typical cases can be included in a maximum variation sampling strategy, if necessary. • Use multi-site and multi-category design: Research that is conducted at different sites or with different categories usually results in findings that can be generalized with greater confidence. For a long time, for example, it was assumed that research done with male subjects could be generalized to women. However, theoretical developments and experience have shown how important it is to include both genders, and analyze both separately and comparatively if valid generalizations are to be made about the whole popul
