Research that incorporates both quantitative and qualitative data is termed "mixed method". Using a mixed method research methodology gives a more complete and synergistic use of data than collection and analysis of quantitative and qualitative data separately (AHRQ, 2013).

Mixed method research methodology gives breadth and depth of understanding while offsetting the weaknesses innate to using quantitative or qualitative approaches individually.

"Triangulation" a term coined in the 1970's to describe mixed methodology, "was identified as a combination of methodologies in the study of the same phenomenon to decrease the bias inherent in using one particular method" (Doorenbos, 2014).

There are various mixed method designs and selection of appropriate design is important prior to implementation of research. When using the convergent design, quantitative and qualitative data is collected at the same time.

It is analyzed separately and compared and displayed side by side. The two types of data validate each other and form a solid basis for drawing conclusions of interventions. The explanatory sequel design involves two phases. The first being a quantitative study followed by a qualitative study that builds on the quantitative. In this way, the qualitative data gives further explanation of the quantitative data.

The embedded design is a quantitative outcomes study, for example a randomized, controlled trial, in which qualitative data collection and analysis is added. Both quantitative and qualitative data are analyzed and the qualitative incorporated at the outset to aid in developing interventions.

The multi-phase design, for example a community-based approach that involves the primary care providers and staff, patients, and other providers and individuals in the community in the research process. Key stakeholders participate as co-researchers in a project, providing input about their needs, ways to address them, and ways to implement changes (AHRQ, 2013).

There are both advantages and disadvantages to using a mixed method research methodology.

Advantages:

Compares quantitative and qualitative data to aid in understanding contradictions between quantitative and qualitative findings.

Reflects participants' point of view by giving a voice to study participants and ensure that study findings are grounded in participants' experiences.

Fosters scholarly interaction by adding breadth to multidisciplinary team research by encouraging the interaction of quantitative, qualitative, and mixed methods scholars.

Provides methodological flexibility and adaptability to many study designs to illuminate more information than can be obtained in quantitative research alone.

Collects rich, comprehensive data by mirroring the way individuals naturally collect information (integrating quantitative and qualitative data).

For example, sports stories frequently integrate quantitative data (scores or number of errors) with qualitative data (descriptions and images of highlights) to provide a more complete story than either method would alone.

Disadvantages:

Increases the complexity of evaluations. Mixed methods studies require careful planning to describe all aspects of research such as: study sample for qualitative and quantitative portions, sequence of quantitative and qualitative portions, and plan for integrating data.

Integrating quantitative and qualitative data is often challenging.

Relies on a multidisciplinary team of researchers using qualitative experts.

Requires increased resources. Mixed methods studies are labor intensive. They require greater resources and time than those needed to conduct a single method study.