Other Design Implications

Unlike single method (mono-method) designs where the sampling, sample size, and measurement are designed for a single quantitative or qualitative design, in mixed methods designs often these aspects of data collection must be selected in a way that allows for both qualitative and qualitative approaches.

This is especially true for concurrent mixed methods designs where the quantitative and qualitative data are collected in the same time frame and typically with the same study participants.

Sample Size: Quantitative studies often rely on large samples, whereas qualitative studies have much smaller samples. Thus, in mixed methods studies, these two competing sample size traditions must be reconciled.

As such, mixed methods studies either gather both qualitative and quantitative data on modest samples (perhaps smaller than typical in quantitative studies but larger than typical for qualitative studies) or a subset of the quantitative sample are selected for in-depth qualitative investigation.

Sampling Design: Likewise, with respect to sampling strategies, quantitative research often relies on samples that are randomly drawn from the population, whereas qualitative research purposefully selects the sample based on specific criteria or quotas. Therefore, in concurrent mixed methods designs, the random sampling procedures often must be compromised to allow for qualitative study.

For example, because qualitative research often relies on smaller samples, qualitative and mixed methods designs are often stratified or use quota sampling to ensure that there is a sufficient number of individuals per group for comparisons.

Samples: The method of recruiting participants for both the qualitative and quantitative aspects of a mixed methods study must also be considered, especially when the goal of the study is to triangulate the findings between the qualitative and quantitative data. To help ensure that the two sources of data are comparable, the participants must be recruited from the same or similar sources. To the extent possible, try to minimize the differences in the sample populations across the two methods.

Measurement: Finally, in all mixed methods designs, both the quantitative and qualitative aspects must ensure that the measurement and content of questions asked address the same topics. This ensures that the two types of data can inform one another or be triangulated later.

Therefore, mixed methods research requires forethought and planning prior to data collection to ensure that all aspects of the data collection are compatible and achieve the study goals.