An update on triangulation

Although the concept of triangulation has been used for 50 years, what triangulation means and how it is used by qualitative researchers varies considerably. This blogpost begins by providing a brief history of triangulation that highlights how the meaning of the term “triangulation” has changed over time as it has been taken up by qualitative and mixed methods researchers.

A brief history of “triangulation”

The concept of triangulation is both recognized and well-used among qualitative and mixed methods researchers across disciplines. Norman Denzin outlined an approach to multi-method naturalistic research (first published in 1970, revised by Denzin in1978 and 1987) that contrasted with Campbell and Fiske’s (1959) argument for application of a multi-trait multi-method matrix approach to validating tests measuring traits. Writing from a positivist perspective toward inquiry, Campbell and Fiske called their approach a “methodological triangulation” and “convergent validation” (p. 101, italics in original). The idea that using multiple measures of a phenomenon, or completing “triangulation” of data would lead to more “persuasive evidence” to validate findings was asserted by other social scientists in the 1960s (Webb et al., 1966, p. 3). This approach assumed that by using multiple measures, researchers could eliminate other plausible explanations (Webb et al., 1966, p. 174).

Asserting that “no single method will ever meet the requirements of interaction theory,” Denzin (1978, p. 28) proposed “triangulation” as an approach to study one object. What is sometimes overlooked in Denzin’s initial formulation is that triangulation encompassed four forms:

  • Data triangulation (i.e., examining multiple concrete situations of phenomenon in order to check emerging propositions, e.g., through multiple interviews or observations over time)
  • Methodological triangulation (i.e., using multiple methods, such as various forms of interviews, observations, or demographic methods)
  • Researcher triangulation (i.e., involving multiple observers to examine the object of study)
  • Theoretical triangulation (i.e., employing multiple theoretical perspectives) (pp. 101-102)

Similarly to Webb et al. (1966), by combining methods Denzin (1978) argued that the researcher would be able to “forge valid propositions that carefully consider relevant rival causal factors” (p. 29).

Scholars have pointed out that multiple data sources, methods, researchers and theoretical orientations will not necessarily lead to convergence on a single point or unitary conclusions as conveyed in the metaphorical origins of the term triangulation (Hammersley & Atkinson, 1995; Lincoln & Guba, 1985; Mathison, 1988). Indeed, Hammersley (2008) has troubled the application of the metaphor of triangulation derived from navigation and surveying to social research. Whereas in navigation and surveying the purpose of triangulation is to identify a specific location, applications in social research frequently involve support for the validity of claims.

How is triangulation used by researchers?

In reviewing how triangulation has been applied by researchers in multiple disciplines, I have observed that “methodological triangulation” appears to be one of the most popular ways in which the concept has been used. That is, scholars use more than one method to examine a phenomenon (e.g., individual interviews, focus groups, participant observation, document analysis etc.). As Denzin (1978) himself noted, this is only one form of triangulation. In its original form, these multiple methods were qualitative (Denzin, 2012, p. 82). Researchers who focus on the use of qualitative methods may be surprised to learn that with the rise in popularity of mixed methods research that encompass both qualitative and quantitative methods, triangulation has come to be used as a synonym for mixed methods research. This transformation in how triangulation as a term is used has led to numerous debates in how it is applied in research and whether the concept is still useful. Denzin (2012) has even claimed that “The term [triangulation] has been used, abused, and misinterpreted” (p. 85).

Innovations in triangulation

Scholars have suggested innovations to the original concept of triangulation. For example, Torrance (2012) has suggested that “member validation” be included in the larger idea of triangulation to support democratic practices in mixed methods research. As another example, Flick et al. (2012) have proposed the idea of “systematic triangulation,” and use an example of a study of sleep disorders in nursing homes to illustrate how this can be done. Flick et al. (2012) comment that:

“Instead of seeing investigator, theoretical, methodological, and data triangulation as alternative forms of triangulation, we can conceptualize them in a more comprehensive way as steps that build on each other. If the issue in question requires more than one approach, it may be necessary to include more than one researcher (investigator triangulation) who should bring different conceptual perspectives into the study (theory triangulation). This should provide the background and should lead to the application of different methodological approaches (methodological triangulation) either within one method or using different independent methods (between-methods). The result of this will be data on different levels and with different qualities (data triangulation). This makes sense as long as we ensure that in these approaches, truly different perspectives are pursued.” (p. 102)

This study by Flick et al (2012) provides a useful example of how “systematic triangulation” might unfold in a study.

Nearly a decade ago in 2012, Denzin called on researchers to reconsider triangulation to fit a postmodern epistemology stating, “hopefully, in the next decade there will be renewed efforts to embed all our interpretive methodologies in expanded social justice discourses” (p. 86). Yet the use of triangulation remains pervasive across disciplines and epistemological approaches to research, even though some have taken up Denzin’s call for considering different approaches (e.g., Ellingson, 2009). Let’s look at one alternative.

An alternative to triangulation

Based on an earlier reference to crystallization by sociologist Laurel Richardson (1994, 2000) Laurel Ellingson has elaborated on the idea of crystallization:

“Crystallization combines multiple forms of analysis and multiple genres of representation into a coherent text or series of related texts, building a rich and openly partial account of a phenomenon that problematizes its own construction, highlights researchers’ vulnerabilities and positionality, makes claims about socially constructed meanings, and reveals the indeterminancy of knowledge claims even as it makes them.” (Ellingson, 2009, p. 4)

Ellingson (2009) offered a number of principles for how to apply crystallization in qualitive inquiry. These include:

  • Offer deep, thickly described, complexly rendered interpretation of meanings about a phenomenon or group.
  • Represent ways of producing knowledge across multiple points of the qualitative continuum, generally including at least one middle-ground (constructivist or postpositivist) and one interpretive, artistic, performative, or otherwise creative analytic approach; often crystallized texts reflect several contrasting ways of knowing.
  • Utilize more than one genre of writing (e.g., poetry, narrative, report) and/or other medium (e.g., video, painting, music).
  • Include a significant degree of reflexive consideration of the researcher’s self and roles in the process of research design, data collection, and representation.
  • Eschew positivist claims to objectivity and a singular, discoverable Truth in favor of embracing knowledge as situated, partial, constructed, multiple, embodied, and enmeshed in power relations. (p. 10)

One recent example of an application of crystallization is provided by Barbosa Neves et al. (2021), who examined loneliness among elderly people in care facilities.

Abandoning the concept of triangulation

Some scholars have called for abandoning the concept of triangulation altogether. Referring broadly to terminology used in mixed methods research Fetters and Molina-Azorin (2017) proposed six principles for abandoning terms, which they illustrated using the concept of “triangulation”:

  1. The described qualitative and quantitative processes must be similar.
  2. Newer, appropriate alternative language emerges that provides more clarity and focus specific to the mixed methods paradigm.
  3. The language invites confusion with another paradigm, or procedure.
  4. The language has multiple meanings and lacks sufficient clarity and precision.
  5. The language is contradictory.
  6. The language implies redundancy (p. 7)

Fetters and Molina-Azorin (2017) proceeded to show how triangulation as a concept is problematic for all of these listed reasons. They asserted that “we believe that the language of integration is better language than triangulation when used in a broad sense, and that the more specific integration terms that have emerged should be favored” (p. 8) by mixed methods researchers. Although Morgan (2019) agreed with the problems posed by use of the concept triangulation, he suggested that building on the advances in understanding how findings from qualitative and quantitative methods might be integrated “creates greater clarity about the differences between convergence, complementarity, and divergence” (p. 10).

Given the ways in which the term triangulation has been applied in varying ways by researchers across disciplines using different research design and methods, what questions might qualitative researchers ask if they intend to use this concept? Here are some initial questions:

  1. What form of triangulation do you plan to use for a study?
  2. What do you want to accomplish in using the concept of triangulation?
  3. How will you define triangulation?
  4. What are the limitations and critiques of triangulation in how you intend to apply it?

As in any aspect of qualitative inquiry, exploring how a concept is defined by different scholars and how it has been used is a productive exercise that will lead to more nuanced applications.

Kathy Roulston


Barbosa Neves, B., Wilson, J., Sanders, A., & Kokanović, R. (2021). Using crystallization to understand loneliness in later life: Integrating social science and creative narratives in sensitive qualitative research. Qualitative Research, Advance online publication.

Campbell, D. T., & Fiske, D. W. (1959). Convergent and discriminant validation by the multitrait-multimethod matrix. Psychological Bulletin, 56(2), 81-105.

Denzin, N. K. (1978). The research act: A theoretical introduction to sociological methods (2nd ed.). McGraw-Hill.

Denzin, N. K. (2012). Triangulation 2.0. Journal of Mixed Methods Research, 6(2), 80-88.

Ellingson, L. L. (2009). Engaging crystallization in qualitative research: An introduction. Sage.

Fetters, M. D., & Molina-Azorin, J. F. (2017). The Journal of Mixed Methods Research starts a new decade: Principles for bringing in the new and divesting of the old language of the field. Journal of Mixed Methods Research, 11(1), 3-10.

Flick, U., Garms-Homolová, V., Herrmann, W. J., Kuck, J., & Röhnsch, G. (2012). “I can’t prescribe something just because someone asks for it . . .”: Using mixed methods in the framework of triangulation. Journal of Mixed Methods Research, 6(2), 97-110.

Hammersley, M. (2008). Troubles with triangulation. In M. M. Bergman (Ed.), Advances in mixed methods research (pp. 22–36). Sage.

Hammersley, M., & Atkinson, P. (1995). Ethnography: Principles in practice (2nd ed.). Routledge.

Lincoln, Y. S., & Guba, E. G. (1985). Naturalistic inquiry. Sage

Mathison, 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), 6-11.

Richardson, L. (1994). Writing: A method of inquiry. In N. K. Denzin & Y. S. Lincoln (Eds.), Handbook of qualitative research (pp. 516-529). Sage.

Richardson, L. (2000). Writing: A method of inquiry. In N. K. Denzin & Y. S. Lincoln (Eds.), Handbook of qualitative research (pp. 923-948). Sage.

Torrance, H. (2012). Triangulation, respondent validation, and democratic participation in mixed methods research. Journal of Mixed Methods Research, 6(2), 111-123.

Webb, E. J., Campbell, D. T., Schwartz, R. D., & Sechrest, L. (1966). Unobtrusive measures: Nonreactive research in the social sciences. Rand McNally College Publishing Company.

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