1. the process of confirming a hypothesis by collecting evidence from multiple sources. There are several different types of triangulation. In data triangulation, various sampling methods are used: The data are collected at different times, from different groups of people, and so forth. Investigator triangulation involves multiple researchers in an investigation; theory triangulation involves using more than one theoretical scheme to interpret a phenomenon; and methodological triangulation involves using a variety of interviews, observations, questionnaires, documents and other data-collection methods. The data from each source support the hypothesis from a somewhat different perspective and therefore increase confidence in its validity.

2. in family therapy, a situation in which two members of a family in conflict each attempt to draw another member to their side. Triangulation can occur, for example, when two parents are in conflict and their child is caught in the middle. —triangulate vb.