Knowledge acquisition in changing realities

Various devices have been identified to support research as a way of improving on observations; those in the social sciences appearing to be less effective than those in the physical sciences. To make the former more effective, it often is tried to "involve" the user - as a participant observer, as a co-researcher, as a commissioner. A clarification of the multiplicity of such attempts seems in order. Formulates a framework to summarize the most important aspects of research. Explores instances of this framework with regard to their ability to include users. One instance is applied in a "practical" situation, the improvement of a social service. This instance distinguishes sharply between two kinds of users, each using a different language to promote transfer and interaction: users inside a collective and users outside that collective.