DEFINITION 1: The use of three or more theories, sources or types of information, or types of analysis to verify and substantiate an assessment.
SOURCE: OECD (2010). Glossary of Key Terms in Evaluation and Results-Based Management, OECD/DAC, Paris.
DEFINITION 2: Sometimes known as 'methodological triangulation', this term is used in a research context to describe the use of a variety of methods to examine specific phenomena either simultaneously or sequentially in order to produce a more accurate and reliable account of the phenomena under investigation; it does not necessarily refer to 'three' approaches.
SOURCE: Hickman, R. (2013). Cambridge Handbook of Educational Abbreviations & Terms ( C.H.E.A.T.),.6th edition, Faculty of Education, University of Cambridge.
DEFINITION 3: Using a mix of approaches (e.g., mixed methods, team members or information sources) to cross-check data for validity and reliability.
SOURCE: Kusters, C.S.L. et al.(2011). Making evaluations matter: A practical guide for evaluators. Centre for Development Innovation, Wageningen University & Research centre, Wageningen, The Netherlands.