Usability criteria sum up cognitions and perceptions of professional methods and problem solutions such as quality assurance in health care. They are important for the dissemination and implementation of innovations and the effectivity and efficiency of systems. In order to extract such criteria in an explorative structured review, publications from five fields were examined: (a) quality assurance in health care, (b) health promotion and education, (c) psychological methodology, (d) evaluation studies, and (e) comparative policy assessment. One hundred thirty-eight English and German basic and applied research contributions were selected. Usability criteria and comments on their interference were extracted. The review provided a two-dimensional taxonomy of the concept of usability. The first dimension is defined by five functional aspects of quality assurance instruments: (1) easy and efficient handling, (2) scope of practical functions and options for usage, (3) completeness of information, (4) users’ compliance and motivation, and (5) scientific quality of results and data. Between these usability areas some characteristic antagonisms are perceived. The second dimension is defined by four levels of increasing precision of professional cognitions: The usability area constitutes level 1. Each consists of several main criteria (level 2). Twenty-one main criteria of usability were found that were each specified by alternative sub-criteria (level 3) and their empirical indicators (level 4). This taxonomy offers an approach to the empirical exploration of users’ expectations concerning quality assurance. It may contribute to the transparency of stakeholders’ perspectives, to the preparation of consensus procedures in QA and to systematical comparison of quality assurance systems.