Triangulation

Types

Norman Denzin identified four types of triangulation. First, data triangulation involves using multiple sources of data in an investigation. In a research study examining hospital staff morale, for example, interviews with medical personnel might be compared and cross-checked with staff surveys and records of focus groups consisting of hospital employees. Second, investigator triangulation involves employing several evaluators to engage in observations or analyze participant responses. Using multiple investigators allows for the auditing of data consistency and reduces the potential bias inherent in employing only one investigator or analyst. For example, a group of researchers analyzing responses to open-ended survey questions might be less likely to draw erroneous conclusions than a single investigator, whose expectations might color interpretations of the data. A related practice known as member checking involves having study participants review transcripts and the findings derived by investigators to verify the accuracy of their recorded responses and comment on the conclusions drawn. Third, in theory triangulation, multiple theoretical perspectives are considered either in conducting the research or in interpreting the data. Employing a multidisci-plinary team is one approach that brings different theoretical perspectives to bear on the research question. Last, methodological triangulation, which is the most commonly used form of triangulation, engages multiple methods to study a single problem. Typically employed to compare data collected through qualitative methods with quantitative data, methodological triangulation can establish the degree of compatibility between information obtained through different strategies. Qualitative and quantitative methods might be employed simultaneously (e.g., distributing a questionnaire and conducting a case study) or might be used in a sequential fashion (e.g., a pilot study serves as the foundation for a randomized controlled trial conducted at a later date). Methodological triangulation might take the form of within-methods triangulation, where multiple [Page 1538]quantitative or qualitative approaches are employed, or between-methods triangulation, where both quantitative and qualitative approaches are used. Within-methods triangulation, on the one hand, has been criticized as a weaker strategy, as it only employs one method (either qualitative or quantitative) and does not compensate for the limitations of the particular paradigm. Between-methods triangulation, on the other hand, offers the possibility that the biases inherent in one approach will be mitigated by the inclusion of other sources of data, methods, and investigators.

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