The fixation of (visual) evidence.

This article is concerned with the fixation of "evidence" or of "sense data", which are factors constructing facts from output and hypotheses of experiments and theories. Sense data tell us whether a particular theory is likely to be correct or not. The point is that just as scientific facts are the end product of complex processes of belief fixation, so visual "sense data," just what it is scientists see when they look at the outcome of an experiment, are the end product of socially organized procedures of evidence fixation. The data presented in the article is derived from an ongoing laboratory study of molecular genetics. The process first involves techniques of manual and instrumental enhancement, second, the visual inspection through an "autoradiograph film", and the third set of practices revolves around "evidence" by which the data actually included in the scientific papers. The autoradiograph film study involves a sequential steps as opening sequence, information-gathering, evaluation and finally the performance recommendation.