Do the students check the internal consistency of scientific texts or do they keep the first information they read?

This paper descrie the prepatarion and application of an instrument designed to assess the strategies students use to control comprehension when they read a short scientific text. It was applied to two groups of students from different school levels. A contradiction was introduced in the text generating two versions of it differing in order of appearance of the right information. Research findings are presented and interpreted according to findings of other studies on this subject.