Pre-defined Terms in Collaborative Indexing Systems: Why Are They Used and Which Impact Do They Have on the Community's Vocabulary?

Collaborative indexing systems have attracted anincreasing amount of attention over the last threeyears. One fundamental limitation to such a system isthe uncontrolled nature of its vocabulary, as thisconsists of terms users freely choose to indexresources. As a result, the vocabulary can be poorlystructured, making it difficult to identifysignificant clusters of users, resources, or termsimportant for search or exploration features.Pre-defined terms are suggested to reduce thisuncontrolled vocabulary; these consolidate termusage if users adopt them. However, this suggestionhas not yet been proved. This work therefore focuseson an empirical study of the adoption of pre-definedterms. The model of pre-defined term adoption (MPTA)is formulated by applying technology acceptanceand diffusion of innovation theories, as well asconstructs of social network analysis. MPTA is thenvalidated by one lab experiment with 172 Germanstudents, before being cross- validated by twoweb experiments with 254 German and 160English-speaking subjects. Results indicate thatpre-defined terms are appropriate for reducing theuncontrolled nature of the vocabulary.