Social indexing is an approach to manual indexing of web content. The purpose of this master thesis has been to investigate terminological and conceptual consistency in social indexing of web content. Conceptual consistency was investigated/measured focusing on synonyms and (the use of) singular and plural forms of words. In order to measure consistency in social indexing data were obtained from the Delicious website. The data set consists of five indexed objects, 3001 tags and 239 users. Synonym tags and singular and plural forms of words were identified and grouped. The indexing consistency was then calculated on five user groups, each containing twenty users. The users’ sets of tags were represented in vector spaces and each user’s vector was measured against the group’s average vector using the cosine measure. The indexing consistency was found to be low. An average terminological consistency of 15.4 % and an average conceptual consistency of 18.5 % were achieved. Synonym tags and singular and plural forms of words do affect terminological consistency but not to any great extent. The low (terminological) consistency may therefore not solely be attributed to the presence of synonyms and singular and plural forms of words among the users’ tags. / Program: Bibliotekarie

The aim for this master’s thesis is to investigate the indexing consistency in a folksonomy Delicious. This is done by investigating how users construct tags. By applying a semiotic perspective and use analysis of content the occurrences of inflected forms, hyponymy, meronymy and users own tag creations were established. Lancaster’s seven factors is the starting point for the discussion about indexing and the factors that affects it in either a negative or positive way. The indexing consistency is calculated for the first twenty users of the five objects that are investigated. For the calculation Rolling’s method has been used but since it focuses on the indexing consistency between two users, it was adapted for the calculation of the average consistency of the first 20 users. The thesis results show that users prefer to use much the same words which mean that the average consistency for all objects is 28.34 %. Like professional indexers, the users of Delicious prefer to tag the objects with nouns and they often use the singular form. Problems arise when users create their own tags because many of these tags only occur one or two times for every object. This affects the indexing consistency in a negative way.