Which research approach includes both qualitative and quantitative data collection methods?

The mixed methods research approach integrates both qualitative and quantitative data collection methods, allowing for a comprehensive analysis of research questions. This approach is particularly valuable because it leverages the strengths of both methodologies. Qualitative data can provide in-depth insights into participants' perspectives and experiences, while quantitative data can offer statistical validation and generalized findings across larger populations. By combining these methods, researchers can gain a richer understanding of complex issues, explore hypotheses in detail, and triangulate results for more robust conclusions.

In contrast, the other options focus exclusively on one type of data. Cross-sectional research often refers to the collection of either quantitative or qualitative data at a single point in time without integrating the two. Quantitative research is strictly concerned with numerical data and statistical analyses, while qualitative research relies on non-numerical data, emphasizing meaning and context. Thus, none of those methods incorporate both qualitative and quantitative approaches, making mixed methods the correct choice for a comprehensive research methodology.