Creswell (2009) provides the explanation of six main, commonly used mixed methods designs, which include as follows:
It appeals to the researcher with strong quantitative inclination. Quantitative data collection and analysis are followed by qualitative data collection and analysis, which build on the results of the initial quantitative results. It is usually used when unexpected results arise from quantitative analyses, and qualitative data collection serves to examine the surprising results in more detail. It is easy to implement because the steps fall into separate stages, and therefore it is easy to describe and report.
First, qualitative data are collected and analysed, followed by a quantitative data collection and analysis that builds on the results of the first, qualitative phase. Quantitative data and results help to interpret qualitative findings, but the aim is to initially explore a phenomenon. It is appropriate when testing elements of an emergent theory resulting from the qualitative phase, as well as to generalize findings to different samples, or when an instrument needs to be developed.
It is a two-phase project, but with a theoretical lens such as gender or race overlaying the sequential procedures. The initial phase can be either qualitative or quantitative, and is followed by the second phase, also either qualitative or quantitative, which builds on the earlier phase. The theoretical lens shapes the research question aimed at exploring a problem, and guides the study.
Sequential designs are visually presented in Figure 2.