Making use of a sociological approach we present in this paper an interpretation for difficulties and mistakes shown by students during programmed activities in a laboratory class. The understanding of typical laboratory concepts such as measurement, uncertainty, fluctuation etc., is analyzed from the written material produced by students, their exercises and reports. We consider that errors and difficulties shown by students in laboratory work originate from a common sense conception concerning physics and the reality it describes and represents. Science is defined within a reality sphere that is different from that considered in everyday life and, inside the scientific sphere, measurement concepts should respect adequate criteria that are established scientifically.
measurement conceptions; laboratory class; science and reality