Free and unstructured collaboration tasks do not systematically produce effective learning. One way to enhance the effectiveness of collaborative learning is to structure interactions by engaging students in well-defined, computer-supported pedagogical scripts. A script (some authors use the term scenario) is a "story" that the students and tutors have to "play", as actors would play a movie script. We conducted a study using three different learning units that are currently embedded in regular high school biology curricula, and focused on the students’ learning processes and results. We constructed these collaborative, hypertext-based pedagogical scripts based on the following formula:

1. A first phase where there is the production of a critical mass of information into the system i.e. a hypertext accessible to all members of the learning community.
2. A second step where students are encouraged to link similar concepts.
3. A third phase where students should sustain the important consideration of the work produced by other members of the community.

These strategies lead to a deeper immersion in the treated subject, better subjective perception of efficiency, and a somewhat increased learning progression.
We focused on the performance of two classes exposed to the same educational concepts but in different scenarios. A regular high school class accomplished their tasks in a conventional learning unit, while a vocational high school class utilized a collaborative hypertext (Swiki). The two groups showed a similar increase in factual knowledge, which clearly shows an experimentation effect. Given the elective Swiss school system, regular high school students would be expected to show a better academic performance than the vocational students, in a comparable learning situation. The vocational class produced a longer and more complex hypertext than the regular class. However, the regular class produced summaries about a wider variety of subjects and showed a better confidence in their knowledge about the subjects. We called our scenarios: Action Based, Hypertext-Constructive, Computer Supported Collaborative Learning units (ABAHCOCOSUCOL) and found numerous possibilities for applying the scripting elements combined with the additional tool to all sorts of learning environments. This may include a face to face learning environment, but also blended learning (with adolescent and adult students), and learning that integrates different subjects.