CONCEPT
Co-Production of Instrument and Fact
Schaffer's principle that scientific instruments and the facts they measure validate each other circularly—the mechanism of all empirical knowledge production.
The co-production thesis holds that instruments and facts do not exist independently but constitute each other through a circular process. Boyle's air pump produced the vacuum as a scientific fact; the vacuum's existence validated the air pump as a reliable instrument. This circularity is not a flaw but the normal mechanism through which experimental knowledge is generated. Before the pump, 'vacuum' was a contested philosophical concept. After the pump and the witnessing community that certified its results, vacuum became an empirical fact that other investigators could build upon. The instrument does not reveal a pre-existing reality; it creates the conditions under which specific phenomena become scientifically knowable. Applied to AI, this framework reveals that productivity metrics do not neutrally measure AI's effects—they co-produce those effects by defining what counts as productivity in terms calibrated to the tool's strengths.
In The You On AI Field Guide
The co-production mechanism operates across every scientific instrument Schaffer has studied. The thermometer defined temperature as the thing thermometers measure, producing a framework