A considerable interest in using Web 2.0 technologies such as wikis in education has been observed recently. Despite the advantages of the wiki technology, a number of questions concerning design of appropriate activities and their learning effectiveness remain open. In this paper, we present the results of three activities involving first-year university students using wikis to learn basic concepts related to information technology. Three activities of different classes were designed and delivered to the students using the framework proposed by West and West (2009). In all studies, a one-group pretest-posttest design was adopted. Results illustrated significant improvement in learning outcomes, particularly for students with low initial performance. The average students' questionnaire score jumped from 39.0/100 to 57.3/100. No significant effect of both students' role in the activity and their school stream on learning gain was observed. Finally, regardless of the activity's class and learning goal, a persistent pattern of high learning gain was observed.