Triangulation
Triangulation means using more than one method to study the same thing. By combining a suite of methods and data sources, we can come to a more complete answer to a question. The term is loosely borrowed from geometry, where it refers to calculating the distance to a point by looking at it from two other points.
For example, an evaluator could use interviews, a survey, and document content analysis together to draw better conclusions. By using multiple methods, data types, or evaluators, we can overcome the weaknesses of any one alone.
See also: qualitative data analysis, quantitative data analysis, mixed methods