# Triangulation

Susan Machum

Triangulation is a term that refers to the collection and use of multiple data sources, research methods, theories, and/or investigator perspectives to verify and corroborate research findings.

Susan Machum is Dean of Social Science and Professor of Sociology at St. Thomas University in Fredericton, New Brunswick, a small Canadian liberal arts college that focuses on instilling critical thinking and social justice in its students. From 2006 to 2016, she held a Canada Research Chair in Rural Social Justice. Her areas of research include women and work, women’s work in agriculture, environmental sociology, rural development and social justice.

## Corroborating Evidence: The Value of Multiple Viewpoints and Perspectives

When police officers try to reconstruct what happened during a traffic accident, they ask all the passengers who were in the vehicles and witnesses to the accident to tell them the details of what happened. But they don’t just rely on eyewitness accounts, they also measure skid marks, how far the vehicles and debris scattered from the point of collision, and the angles of impact. They take photographs of the scene, check if airbags were deployed, and evaluate the extent of damage to each vehicle, especially when the accident involves a fatality. As Weiss notes, “the collision reconstruction may include pre-impact speed, and change of velocity… The principal direction of force, collision duration, and peak or average vehicle acceleration may also be evaluated” (2007, p. 2). Armed with varying accounts, measurements, photographic evidence, and follow-up research and analysis, the accident reconstructionist will establish who was at fault, and potentially lay charges. This method relies on multiple sources of evidence to draw a reliable and valid conclusion about what transpired.

Using multiple vantage points, data sets, and methods of inquiry is at the heart of triangulation. As the name suggests, triangulation is built on the laws of trigonometry and our measurement of triangles. That is, if we know one side and two angles of a triangle, we can use mathematical formulas to accurately calculate the other angle. Surveyors—and modern-day GPS technology—have long used three or more known points to identify the position of particular locations. By considering multiple vantage points, there is less likelihood of error, meaning that findings are more valid and reliable than if we had used only one or two points.

Triangulation was introduced into social science research in 1959 (Fiske & Campbell), with the agenda of building the most comprehensive and coherent pictures of the social situations under investigation. Since then, many researchers have built research projects that include multiple data sources and methods of data collection; in fact, triangulation is considered the cornerstone of mixed methods research. Denzin was an early adopter and he identified four key types of triangulation (2015):

Data triangulation involves collecting information from multiple sources to establish what occurred from different angles. In the example of an accident reconstruction, investigators interview passengers, witnesses, and car mechanics.

Methodological triangulation refers to using different research methods such as interviews, surveys, participant observation, photography, video, and ethnography, among others, to collect data in a variety of ways and for differing forms of analysis. In a car accident reconstruction, this could mean collecting witness statements, deposition transcripts, photographs, videos, debris, and collision measurements.

Theory triangulation requires researchers to look at the material from different explanatory perspectives and frameworks. Accident reconstructionists would review all the data collected to determine the velocity, acceleration, energy, and momentum of the vehicles at the time of impact, in order to explain the principal direction of force that occurred at the time of the collision.

Investigator triangulation occurs when more than one person takes part in the research, such as when multiple police officers examine a traffic accident or help analyze the data that was collected. When investigators come from different disciplines, the process and results are described as multi- or interdisciplinary.

Even though triangulation can be an imperfect process, taking multiple vantage points, sources of information, and theoretical frameworks to measure and evaluate the social world is a powerful social science strategy. Not only are the findings of triangulated research likely to be more sound, those who conduct their research in this way are considered more credible. Whether the investigation involves human social dynamics or the reconstruction of a traffic accident, triangulation is a tactic and strategy that helps achieve more reliable and valid outcomes.

Discussion Questions

• Have you ever been asked to describe what caused the eruption of a major argument between you and a friend, or what happened during an accident, robbery, or other crime that you witnessed? How confident were you about your recall? Were there aspects of the event that were very clear and easy to recount, and others that were hazier in your memory? If so, what do you think made some details clearer and others vaguer and more distorted?
• Triangulation implies the need for at least three vantage points. Do you think that three data sources are too many? When would one or two sources be enough? And are there instances when we should be looking for even more data points and frameworks than three?
• Do you agree with the idea that there is no single ‘correct’ theoretical framework for understanding a context, and that multiple theories support better findings? Why or why not?

Exercise

Sitting in a circle with your colleagues in a room, identify an item that everyone can see, such as a door (it is best to pick an item that does not exist in multiple versions).

• Have several people describe the physical location of the object in relation to where they are sitting. For example, the door may be located directly in front of one person, but to the left of another.
• After several answers have been collected, discuss who is right.
• Given that all of the answers are correct, in terms of where the individual person is sitting, go on to discuss the different value of the information from each of the vantage points. Does this give you a more precise account of where the door (window, desk, blackboard, screen, etc.) is located in the room?
• With the group, consider the effect using multiple methods (photography, sketches, measurements, participant observation, etc.) in collecting the information about the door (or other object).
• Discuss how our worldviews and experiences affect what we see and report in our descriptions of things (and even our ability to recognize the item we are asked to find and describe).

Campbell, D.T., and D.W. Fiske (1959). Convergent and Discriminant Validation by the Multitrait-multimethod Matrix. Psychological Bulletin, 56(2), 81-105.

Denzin, N.K. (2015). Triangulation. Ritzer, G. (ed.). Blackwell Encyclopedia of Sociology. Hoboken: John Wiley & Sons: 5083-5088.

Flick, U. (2018a). Doing Triangulation and Mixed Methods. 2nd edition. London: Sage Publications.

Flick, U. (2018b). Triangulation in Data Collection. Flick, U. (ed.). Sage Handbook of Qualitative Data Collection. London: Sage Publications: 527-544.

Fusch, P., G.E. Fusch, and L.R. Ness (2018). Denzin’s Paradigm Shift: Revisiting Triangulation in Qualitative Research. Journal of Social Change, 10(1), 19-32.

Matheson, S. (1988). Why Triangulate? Educational Researcher, 17(2), 13-17.

Morgan, D.L. (2019). Commentary—After Triangulation, What Next? Journal of Mixed Methods Research, 13(1), 6-14.

Noble, H. and R. Heale (2019). Triangulation in Research, with Examples. Evidence Based Nursing 22(3), 67-68.

Turner, S.F., L.B. Cardinal, and R.M. Burton (2018). Research Design for Mixed Methods: A Triangulation-based Framework and Roadmap. Organizational Research Methods, 20(2), 243-267.

Weiss. K.D. (2007 November). Auto Accident Reconstruction: The Basics You Must Know: Understanding What the Engineer is Talking About and How Conclusions are Reached. Plaintiff Magazine. URL: https://www.plaintiffmagazine.com/images/issues/2007/11-november/reprints/Weiss_Auto-accident-reconstruction_The-basics-you-must-know_Plaintiff-magazine.pdf