A research project on French high school pupils' information curriculum is held for the development of a media and information culture construction. Researchers have been observing, recording and interviewing 150 pupils in groups and individually during a research activity in 3 different high-schools. The project is based on a qualitative, ethnographic methodology to observe information and pupils' transliterate practices on one hand, and the training practices of teachers-librarians on the other hand. The results show the importance of the teacher librarian's commitment on the transliteracy process.