Mixed Methods Research has been defined as "a type of research design in which QUAL and QUAN approaches are used in types of questions, research methods, data collection, and analysis procedures, and/or inferences" (Tashakkori & Teddlie, 2003a, p. 711). Another definition appeared in the first issue of the Journal of Mixed Methods Research, in which MM research was defined as "research in which the investigator collects and analyzes data, integrates the findings, and draws inferences using both qualitative and quantitative approaches or methods in a single study or program of inquiry" (Tashakkori & Creswell, 2007b, p. 4)
From: Teddlie, Charles., and Abbas. Tashakkori. Foundations of Mixed Methods Research : Integrating Quantitative and Qualitative Approaches in the Social and Behavioral Sciences. Los Angeles: SAGE, 2020.