What type of design typically allows the researcher flexibility to use both qualitative and quantitative methods?

The choice of mixed-method research designs is accurate because these designs are specifically structured to incorporate both qualitative and quantitative approaches. This flexibility allows researchers to gather richer, more nuanced data by combining numerical data analysis (quantitative) with detailed narrative insights (qualitative). For instance, a researcher might start with qualitative interviews to explore a phenomenon in depth and then use quantitative measures to assess the overall prevalence or impact of that phenomenon across a larger sample.

This approach is advantageous as it enables triangulation, which can enhance the validity of the research findings by allowing different methods to complement each other. The ability to switch between methods provides a comprehensive view that can lead to more effective conclusions and recommendations.

The other choices, while valuable in their own contexts, do not inherently support the combination of both qualitative and quantitative methodologies in the same integrated manner.