Students currently have to invest much time doing group assignments, and it is expected that they will have to invest some more with the European credits system (ETCS). As they do not always take enough profit of their time working in group, we tried a new methodology of group work using a fairly new computer tool in teaching and learning environments, called Wiki (Cunningham 1998, Schneider 2004). After two years of use in the auspices of some projects related to innovation in teaching, we collected a list of advantages and disadvantages of the new methodology from the opinions of the teaching staff who had used it. Besides, we collected opinions from surveys to students using traditional methodology of group work and to others using Wiki methodology. Five main conclusions arose from the qualitative results of the experience:

1. Teaching staff appraised in Wiki methodology the easiness and speed of access, version control, registry of who, when and what changed in each document, even if some minor disadvantages were also noted;
2. Students from all subjects using Wiki methodology showed in surveys less negative comments than students with traditional methodology;
3. Letting others to see or modify your work is worth, even when it's not finished and you fear that others read your "work in progress" which may be messy or with important gaps;
4. The role of "Editor in chief" is very important and needed for higher final quality of the work produced, regardless of methodology followed. This task is apparently facilitated by Wiki methodology; and
5. If some "good practice" recommendations are taken into account, there are higher chances that Wiki methodology increases the efficiency of writing documents cooperatively, respect to traditional methodology.