A wiki is a collaborative authoring environment that can be used to reach certain pedagogical objectives, in particular when the underlying pedagogy is social constructivism. This learning theory asserts that learning occurs by reconstructing knowledge in social activity. Wikis can be used to support group activities, peer and tutor reviewing and knowledge creation and sharing activities. Some people would say that these are the ‘affordances’ of wikis. The learning artefact is usually a collectively authored text. Sukaina Walji provides an excellent overview on wikis in a FAQ format on her blog.
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