Computers are often seen as an icon of modernity at schools. Nevertheless, the presence of a sophisticated machine does not guarantee that any real changes regarding students autonomy and critical thinking is going on. This research aimed at investigating the use of computers as teaching tools, focusing on the discursive patterns occurring between teacher and students. It was based upon the knowledge of traditionally asymmetric interactions usually encountered in formal teaching/learning situations, contrasting such paradigm with data collected through systematic observation – and later transcription of recordings - of classes taking place in the computer laboratory of a public school in Rio de Janeiro. The investigation searches for moments in which this pattern changes, thus showing that some real difference is on arrival. The conclusions seem to indicate that the computer alone does not determine variations in the pattern and the consequent advance towards greater autonomy in students participation. However, the teacher s attitude appears to be a crucial factor in triggering the desirable changes.