Purpose - The purpose of this paper is to provide an introduction and overview of the various papers in this special issue. Design/methodology/approach - A short discussion of the main quests of interventionist research and how these are related to the papers in this special issue, is undertaken. Findings - The essence of interventionist research is its methodological location, researching where practice and theory meet. Research limitations/implications - Interventionist research places strong demands on the individual researcher's interpretative, social, and abstracting skills in order to carry observations to ontological and epistemological levels. Practical implications - Interventionist research is rich in research designs and specific intervention types. Selecting the "right" one is strongly related to the connection the researcher makes with the social context she/he will operate in. Changes over time in both design and intervention can be expected, given the dynamic, longitudinal and interactive nature of interventionist research. Originality/value - This special issue provides examples of a varied set of interventionist research situations, including the selection of typical intervention methods and how knowledge contributions were extracted.