This article deals with the topic of mixed mode data collection in quantitative social research. The first part of the article introduces mixed mode data collection in terms of its development, characteristics and terminology. Thereafter, there is a discussion of mixed mode data research design and its usage. In the second part of this paper there is a discussion of important criteria in the effective used of a mixed mode data research design. Here particular attention is devoted to mode effects. The main insights from this overview of mixed mode data research are summarised in a schematic format. The concluding section provides a brief summary of a number of statistical methods for analysing mixed mode data such as Multitrait multimethod (MTMM) approach to studying construct validity. There are also some remarks regarding future developments in mixed mode data collection and analysis in the social sciences.