Concepts have often been described as or in analogy with technologies. Expressions such as technical term, term of art, conceptual tools, or, more recently, conceptual engineering suggest that scientists and other professional groups use terminologies and the concepts they express to certain ends and that terms and concepts are subject to improvement with respect to the purposes at hand. Concepts studied from a historical and philosophical perspective in the Practices of Validation in the Biomedical Sciences Research Group, such as validity, specificity, and sensitivity, are examples of technical terms in biomedical research and practice. In this context, my project asks from a philosophical and historiographical-methodological perspective what is implied when terms and concepts are seen as technologies and how this informs the understanding of the histories of concepts and their role in creating and representing knowledge. The analysis of the notion of concepts as technologies will enable me to engage a number of issues that have been addressed in the history of and philosophy of scientific concepts, such as the relation of terms and concepts, the functioning of boundary concepts that are used by members of different professional groups, the different virtues of vague vs. precise concepts, the operationalization of concepts, the place of individual concepts in conceptual systems, the social vs. epistemic goals of using concepts, the thick (i.e. value-laden) vs. thin nature of concepts, as well as the transfer of actors’ concepts into the language of analysts of science.