What do we expect from students' physics laboratory experiments?

We want physics specialized high school and college students to think like physicists, and this involves an understanding of the scientific methods of inquiry and the ability to use these methods in their own investigations. In order to do that, students have to be made aware that no experimental result has any physical meaning unless an estimate of the uncertainty or precision is assigned to it. In this paper, we describe two simple experiments in which high school and college students measure physical constants, and make an easy analysis of their experimental data by applying the tools offered by microcomputers.