Comparing the hierarchy of author given tags and repository given tags in a large document archive

TL;DR

This paper compares user-generated folksonomy hierarchies with repository-defined hierarchies in a large document archive, revealing significant differences at lower levels but similarities at higher levels.

Contribution

It applies a novel method to analyze and compare hierarchies derived from independent user tags and centralized repository tags in large datasets.

Findings

Substantial differences in lower hierarchy levels

High similarity at the top of hierarchies

Insights into user vs. system categorization patterns

Abstract

Folksonomies - large databases arising from collaborative tagging of items by independent users - are becoming an increasingly important way of categorizing information. In these systems users can tag items with free words, resulting in a tripartite item-tag-user network. Although there are no prescribed relations between tags, the way users think about the different categories presumably has some built in hierarchy, in which more special concepts are descendants of some more general categories. Several applications would benefit from the knowledge of this hierarchy. Here we apply a recent method to check the differences and similarities of hierarchies resulting from tags given by independent individuals and from tags given by a centrally managed repository system. The results from out method showed substantial differences between the lower part of the hierarchies, and in contrast, a relatively high similarity at the top of the hierarchies.