Can all tags be used for search?

TLDR

Collaborative tagging has become a popular means of sharing and organizing Web resources, yet it remains unclear whether tags or subsets of them can effectively support search. This study is the first to examine tagging behavior across diverse systems—Del.icio.us, Last.fm, and Flickr—and to compare the findings with anchor text characteristics. The authors analyze and classify sample tags from these platforms, provide distribution statistics, assess overlap with content and expert metadata, and evaluate the potential of tags for improving search by comparing them with user queries and a survey. The results are promising, offering insights into how different kinds of tags can enhance search and suggesting extensions to tagging systems that facilitate the creation of search‑relevant tags.

Abstract

Collaborative tagging has become an increasingly popular means for sharing and organizing Web resources, leading to a huge amount of user generated metadata. These tags represent quite a few different aspects of the resources they describe and it is not obvious whether and how these tags or subsets of them can be used for search. This paper is the first to present an in-depth study of tagging behavior for very different kinds of resources and systems - Web pages (Del.icio.us), music (Last.fm), and images (Flickr) - and compares the results with anchor text characteristics. We analyze and classify sample tags from these systems, to get an insight into what kinds of tags are used for different resources, and provide statistics on tag distributions in all three tagging environments. Since even relevant tags may not add new information to the search procedure, we also check overlap of tags with content, with metadata assigned by experts and from other sources. We discuss the potential of different kinds of tags for improving search, comparing them with user queries posted to search engines as well as through a user survey. The results are promising and provide more insight into both the use of different kinds of tags for improving search and possible extensions of tagging systems to support the creation of potentially search-relevant tags.