Folksonomy is the system in which users apply public tags to online items, typically to make those items easier for themselves or others to find later. Over time, this can give rise to a classification system based on those tags and how often they are applied or searched for, in contrast to a taxonomic classification designed by the owners of the content and specified when it is published.[1][2] This practice is also known as collaborative tagging,[3][4] social classification, social indexing, and social tagging. Folksonomy was originally "the result of personal free tagging of information [...] for one's own retrieval",[5] but online sharing and interaction expanded it into collaborative forms. Social tagging is the application of tags in an open online environment where the tags of other users are available to others. Collaborative tagging (also known as group tagging) is tagging performed by a group of users. This type of folksonomy is commonly used in cooperative and collaborative projects such as research, content repositories, and social bookmarking.

The term was coined by Thomas Vander Wal in 2004[5][6][7] as a portmanteau of folk and taxonomy. Folksonomies became popular as part of social software applications such as social bookmarking and photograph annotation that enable users to collectively classify and find information via shared tags. Some websites include tag clouds as a way to visualize tags in a folksonomy.[8]

Folksonomies can be used for K-12 education, business, and higher education. More specifically, folksonomies may be implemented for social bookmarking, teacher resource repositories, e-learning systems, collaborative learning, collaborative research, professional development and teaching.

Benefits and disadvantages

Folksonomies are a trade-off between traditional centralized classification and no classification at all,[9] and have several advantages:[10][11][12]

  • tagging is easy to understand and do, even without training and previous knowledge in classification or indexing
  • the vocabulary in a folksonomy directly reflects the user’s vocabulary
  • folksonomies are flexible, in the sense that the user can add or remove tags
  • tags consist of both popular content and long-tail content, enabling users to browse and discover new content even in narrow topics
  • tags reflect the user’s conceptual model without cultural, social, or political bias
  • enable the creation of communities, in the sense that users who apply the same tag have a common interest
  • folksonomies are multi-dimensional, in the sense that users can assign any number and combination of tags to express a concept

There are several disadvantages with the use of tags and folksonomies as well,[13] and some of the advantages (see above) can lead to problems. For example, the simplicity in tagging can result in poorly applied tags.[14] Further, while controlled vocabularies are exclusionary by nature,[15] tags are often ambiguous and overly personalized.[16] Users apply tags to documents in many different ways and tagging systems also often lack mechanisms for handling synonyms, acronyms and homonyms, and they also often lack mechanisms for handling spelling variations such as misspellings, singular/plural form, conjugated and compound words. Some tagging systems do not support tags consisting of multiple words, resulting in tags like “viewfrommywindow”. Sometimes users choose specialized tags or tags without meaning to others.