Triangulation 101


“The process of collecting data from several different sources or in different ways in order to provide a fuller understanding of a phenomenon.

Obtaining data from more than one source (e.g. interviews, observations, and documents) is the most commonly used type of triangulation” (Richards, J. & Schmidt, R.W., 2003).

“ Triangulation, a term commonly used in qualitative research in particular, refers to the integration of different kinds and sources of information in investigations of a particular phenomenon, typically as part of the process of validation or establishing credibility of the study” (Duff, 2012)


Triangulation is a method originally used to determine the location of a fixed point based on the laws of trigonometry. These laws state that if one side and two angles of a triangle are known, the other two sides and angle of that triangle can be calculated.

The origins of triangulation are not known, but it was widely used in ancient Egypt and Greece. Over the centuries, triangulation was applied in maritime navigation, where sailors used it to track their position and course. Historically, it has also played an essential role in surveying and civil engineering.

Triangulation is the principle behind the GPS or Global Positioning System technology. A GPS receiver processes radio signals sent from four different satellites to determine longitude, latitude and altitude. The fourth satellite is used to improve the precision of the measurement.

“Triangulation was first applied to research by Campbell and Fiske (1959) and developed by Webb (1966), who argued that researchers should employ more than one instrument to measure variables. The method was first associated with quantitative research but its relevance to qualitative methods was soon explored” (Wilson, 2010).

Denzin (1970) was a major proponent of the use of triangulation by researchers working within the interpretivist paradigm. In the 1970s, triangulation began to be used as a sociological method. In this field, triangulation was defined as a process of combining data from different sources to study a particular social phenomenon. Since then, it has been applied as a way to improve analysis and interpretation of results from different studies (Hales, 2010).


1) “data triangulation”- the use of different sources of information

2) “investigator triangulation” - the use of several different investigators within the same field of study using the same methods or

“epistemological triangulation”- the use of different perspectives of investigators, e.g. “emic” vs “etic” (Duff, 2012)

3) “theory triangulation”- the use of multiple theoretical perspectives to interpret the data

4) “methodological triangulation” - the use of multiple methods

5) “interdisciplinary triangulation”-the use of people from different disciplines with different perspectives

6) “environmental triangulation”-the use of different locations, settings, time, day, or season (Guion, Diehl, & McDonald, 2011)

“time triangulation” and “location triangulation” (Brown & Rogers, 2002)

WHY TRIANGULATE? (Hales, 2010)

“The greater the triangulation, the greater the confidence in the observed findings”

(Norman Denzin, 1970)

  • When seeking to answer complex questions concerning a study.

  • When there are sufficient data but they are dissimilar, triangulation can balance the different perspectives and lead to a valid conclusion or a new hypothesis that can be tested.

  • Triangulation can compensate for the poor quality of some of the data, assuming that the validity and reliability of the other data can be confirmed.

  • When directly applicable data are not available, triangulation may be able to use indirectly applicable data to draw a valid conclusion.

  • When there is a need for a rapid response, triangulation — using readily available data — can provide a valid perspective far more quickly than collecting and analysing new data.


  • It can enhance the validity and reliability of observed findings

  • It can generate new, credible findings about a situation or phenomenon and can create new ways of looking at a situation or phenomenon.

  • It provides a better understanding of a situation or phenomenon.

  • With triangulation, data will be drawn from a diverse set of sources, ensuring a more expansive look at the situation.


  • Time consuming.

  • Requires greater planning and organization. Complexities of dealing with large quantities of data.

  • Disagreement because of investigators' biases, different theoretical frameworks/hypotheses and/or methods.

  • Difficulties of interpretation when data do not agree.

  • Lack of understanding among policy/decision-makers of the purposes of triangulation strategies use (Guion, Diehl, & McDonald, 2011).


Duff, P., Anderson, T., Ilnyckyj, R. (2013). Learning Chinese: Linguistic, sociocultural, and narrative perspectives. De Gruyter.

Objective: to examine linguistic, sociocultural, and meta-natrative aspects of Chinese language learning in a collaborative participatory longitudinal multiple-case (auto-ethnographic) study

Participants and setting: five anglophone team members, learning Chinese as an additional language (CAL, non-beginners) and who undertook the analysis of the process of learning together with a sixth team member, a Chinese applied linguist.

Data collection: 1) narratives generated by participants (N1); 2) reciprocal and collective annotation of narratives; 3) oral proficiency interview 1, transcription; 4) revision and updates of narratives (N2); 5) oral proficiency interview 2, transcription; 6) revision of narratives (N3)

Findings: similarities and differences in oral/written proficiency, trajectories; relationship between proficiency and social constructs


Denzin, N. K. (2012). Triangulation 2.0. Journal of Mixed Methods Research, 6(2), 80-88. This paper proposes a third way of conceptualizing mixed methods research, one that is based on critical interpretive methodologies.

Ellis, N. C., Simpson-Vlach, R. & Maynard, C. (2008). Formulaic language in native and second language speakers: Psycholinguistics, corpus linguistics, and TESOL. TESOL Quarterly, 42(3), 375-396. This research paper triangulates the construct of formula from corpus linguistic, psycholinguistic, and educational perspectives. It summarizes three experiments which show that different aspects of formulaic language affect the accuracy and fluency of processing of these formulas in native speakers and in advanced L2 learners of English.

Gorard, S. & Taylor, C. (2004). Combining methods in educational and social research. Conducting educational research. Open University Press. This book argues the case for combining multiple research methods. It is a practical guide for researchers who want to use this mixed-methods approach. The book outlines and evaluates methods that are currently used, and looks at combining different methods across and within studies, including triangulation.

Hesse-Biber, S. (2012). Feminist approaches to triangulation: Uncovering subjugated knowledge and fostering social change in mixed methods research. Journal of Mixed Methods Research, 6(2), 137-146. This article explores the use of triangulation to uncover subjugated knowledge and promote social change for women and other oppressed groups. An analysis of selected case studies of feminist praxis explores the specific reasons feminist researchers employ triangulation, and the strengths and weaknesses they encountered in the process of implementing a mixed methods design.

Howe, K. R. (2012). Mixed methods, triangulation, and causal explanation. Journal of Mixed Methods Research, 6(2), 89-96. This article distinguishes a disjunctive conception of mixed methods/triangulation from a conjunctive conception. It examines a more inclusive, holistic conception of mixed methods/triangulation that accommodates different findings by bringing them under a more comprehensive framework.

Spolsky, B. (2000). Anniversary article. Language motivation revisited. Applied Linguistics, 21(2), 157-169. This paper challenges Lambert’s hypothesis who claimed that integrative motivation affected advanced levels of phonology and semantics. It says that Lambert himself seemed to have been open to the more discursive methods now favored by scholars not satisfied with using only questionnaires to gather data. It calls therefore for triangulation of methodology, using also hard sociolinguistic data and personal statements of second language learners, and provides some examples taken from studies of Palestinian Arabic and from studies of immigrants to Israel from the former Soviet Union learning Hebrew.

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

This article argues that triangulation is an important component of mixed methods designs. Triangulation has its origins in attempts to validate research findings by generating and comparing different sorts of data, and different respondents’ perspectives, on the topic under investigation. It also claims that attention to respondent validation is a significant issue for methodological debate and that it should be an important aspect of the development of democratic participation in Mixed Methods Research.

Turner, P., & Turner, S. (2009). Triangulation in practice. Virtual Reality, 13(3), 171-181.

This paper presents the concept of triangulation and when it is used. It describes it as the means by which an alternate perspective is used to validate, challenge or extend existing findings. It distinguishes between the use of hard and soft triangulation--the former emphasizing the challenging of findings, the latter being more confirmatory in character.

van Compernolle, R.,A., & Williams, L. (2011). Metalinguistic explanations and self‐reports as triangulation data for interpreting second language sociolinguistic performance. International Journal of Applied Linguistics, 21(1), 26-50.

The study reported here explores the use of learners' metalinguistic explanations and self‐reports of variable language production as triangulation data for interpreting second language (L2) sociolinguistic performance, focusing on the variable retention versus omission of the negative morpheme ne. The results illustrate how multiple data sources can provide a multidimensional view of sociolinguistic performance that is not necessarily revealed when performance data alone are considered as a single source of analysis.

Vedung, E., Larsson, C. G. (2013). A triangulation approach to impact evaluation. Evaluation, 19(1), 56-73.

This article presents a viable method to overcome the challenge of producing reliable cause–effect findings in impact evaluation. Three designs − shadow controls, generic controls, and process tracing − are combined to shed light on causality. When these three approaches are triangulated, cause–effect findings will be more reliable.


Brown, J.D. & Rogers, T.S. (2002). Doing Second Language Research. Oxford University Press.

Duff, P. (2012). Triangulating theories, methods, and Perspectives in SLA research (Abstract). Retrieved from

Gorard, S., & Taylor, C. (2004). What is triangulation? Building Research Capacity, 7-9.

Guion, L., Diehl, D. & McDonald, D. (2011). Triangulation: Establishing the Validity of Qualitative Studies. Retrieved from

Hales, D. (2010). An Introduction to Triangulation. UNAIDS.

Richards, J. & Schmidt, R.W. (Eds.). (2003). Longman Dictionary of Language Teaching and Applied Linguistics. Longman: UK

Wilson, A. (2010). University of Strathclyde. Retrieved from Introduction to Mixed Methods.

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