Triangulation is a research design that combines both qualitative and quantitative methods to gather data for an overall interpretation that looks at a variety of different factors. The term "triangulation" or "concurrent triangulation" comes from the three concurrent levels of testing in many triangulation studies: first the quantitative level (such as interviewing and observation), then a qualitative level (such as a survey and statistical analysis of outcome data) and then a quantitative analysis that incorporates the findings from the other two tests.

Cross Validation

The primary advantage of triangulation designs in research studies lies in the ability to find agreement and validation of results through a variety of research methods. If different research methods come to the same conclusion, the researcher can be more confident that the results are truly a reflection of what is actually happening and not a reflection of the method of testing used to gather the data.

Balance Between Methods

The qualitative research methodology focuses on stories, exploration, contextualizing, introspection and theory construction. It uses small sample sizes and in-depth study of single occurrences. On the other hand, quantitative research focuses on large groups, trends and patterns. By combining these methods, a researcher can find trends and inconsistencies through quantitative research, then use qualitative methods to dig into those issues, find out why they occur and learn the thoughts of the individuals involved.

Investigator Triangulation

Another way researchers use triangulation involves having two or more researchers gather data. This practice compensates for researcher bias and guards against different assumptions a researcher may have that could influence the results of a study.

Disadvantages of Triangulation

The drawbacks of triangulation include the lack of a uniform methodology for applying triangulation. Those who use triangulation often fail to explain their techniques adequately and use varying methods for combining results. Another problem is that graduate students are often trained in either qualitative or quantitative methods and may not have adequate training in the opposite methods to implement a valid and effective study.