Penultimate draft . 10 . 23 . 2009 ] MODELING AND EXPERIMENTING

Experimental activity is traditionally identified with testing the empirical implications or numerical simulations of models against data. In critical reaction to the ‘tribunal view’ on experiments, this essay will show the constructive contribution of experimental activity to the processes of modeling and simulating. Based on the analysis of a case in fluid mechanics, it will focus specifically on two aspects. The first is the controversial specification of the relevant parameters of phenomenon.. The second is conceptual innovation, with a redefinition of concepts central to the understanding of the phenomenon. In the tribunal function traditionally assigned to experimental activity, experiments are viewed as the place where empirical implications or numerical simulations of theoretical models are confronted with outcomes of measurements, the data. But that supposes that it is clear what the correct theoretical implications, the correct simulation conditions, and the correct data are. By contrast and in reaction to the ‘tribunal view’ on experiments, this essay will show that experimental activity, first of all, plays an essential role in the task of clarification. It will show the elaboration of an experimental system as an interactive, creative, open-ended process, and highlight its constructive contribution to 1 The author wishes to acknowledge helpful discussion and correspondence with Paul Teller , Joseph Rouse, Ronald Giere and James Bogen.