Wikis are one of Web 2.0 tools that can be used in the e-learning process. This article investigates how to engage students to use wiki environment. The study is based on cognitive learning theory and engagement theory. This article evaluates how learner's activity in wiki depends on interaction with teacher. Direct observation, subject teaching, literature and wiki statistical data are used to analyse student activity in a wiki environment. The results of the research indicate that appliance of wiki in informal adult learning is low when teacher do not facilitate learning process. Moreover, the author makes some recommendations for improving learning process in wiki environment to support education for sustainable development.