In the face of ongoing disappointment with some dominant forms of e/valuation and their conceptual repertoires, this workshop wants to explore a version of e/valuation that puts experimentation in the middle of things. Experimentation is in the doing and in the now. It is a continuous arrangement and engagement of valuation practices, ambitions, requirements and actors, both human and less fleshy kinds. It implies neither a closed protocol, nor an open-ended process; it is neither reductive, nor fully exploratory. This is where we locate the experimental in the evaluative: in the continuous tinkering of this gauging engagement.