Folksonomies: Indexing and Retrieval in Web 2.0

By Isabella PetersPresented by:

Curtis Naphan & Shahid Zia QaisraniCMN 5150Fall 2011

On the Author

• Dr. Isabella Peters, M.A.• Specializes in

Information Science• Researcher and Lecturer

at Heinrich-Heine-Universität in Düsseldorf, Germany

Source: http://www.isi2011.de/programm/vortrag.php?id=9

On the Book

• Published in 2009• Part of the Knowledge &

Information book series• Originally in German• Thorough and “sober” analysis

of folksonomies• Not casual reading but a good

resource for those who need to know

Source: http://www.amazon.com/Folksonomies-Indexing-Retrieval-Knowledge-Information/dp/images/3598251793

How the Book is Structured• Where are folksonomies being used today?• What are the various characteristics?

Overview of Collaborative

Information Services

• What are some relevant concepts in folksonomies?• What are the alternatives?

Overview of Terminology and

Models

• How can folksonomies help capture knowledge?• What are the benefits and drawbacks?

Folksonomies for Knowledge

Representation

• How can folksonomies help retrieve knowledge?• How do they compare with traditional methods?

Folksonomies for Information Retrieval

Overview of Folksonomies

A look at how folksonomies are being used today

What are they?

• The use of tags to index and retrieve content

FOLKSONOMY

dogfunny gun

spot

Why are they used?

• Web 2.0– User-generated content– Little formal curation

• Taxonomies too restrictive– “If hierarchies were a good way to organize links,

Yahoo would be king of the hill and Google an also-ran service.” (Shirky, 2004)

• Full-text search not enough– Non-textual resources– Collaborative browsing

Where are they used?

• Incorporated into many applications

• Some differences:– Tag my stuff vs. tag

everyone’s stuff– Content belongs to

me vs. Content is public

Social Bookmarking

• Users add bookmarks• User can tag bookmarks• Link can be tagged by

multiple users• Tags aid:– Personal retrieval– Collaborative browsing– Search

• Often used for PKM

Examples• Del.icio.us• Diigo• Bibsonomy• CiteULike

Link Tags Recommended Tags

E-Commerce

• Users can tag products• Complements search and professional

directory• Example: Amazon.com

Knowledge Bank

• For researchers and engineers • Tag Widget • Simple and Advance Search • Boolean AND• Multi-user tagging• Example: Engineering Village

Streaming Radio

• Example: last.fm• Songs streamed and played up to 3 times• Remunerated for playback• Collaborative rating system • Taste and listening habits • Tag-based recommender system

Libraries, Museums

• Tagging real-life objects via web• Complements traditional indexing methods

Examples• LibraryThing• Stevemuseum

romancicero marble bust

Photosharing

• Users can tag any photo• Aids search, browsing

Examples• Flickr

• Tagged and rated blogs• Search engine and directory• Tag generator code

Twitter

• Slightly different implementation– Tags extracted from #hashed keywords

• Twitter adds:– Users following users– Messages linked to @users

user

link to other user

hash-tag

Tagging Games

Overall Remarks

• Each application’s implementation of folksonomies is different

• Subject matter is crucial– Altruism is rare (Wikipedia)– Personal gain is important motivation (del.icio.us)

• Implementation is important– Must be easy to use– Often few features

• Usefulness tends to increase when alternative indexing and retrieval methods are insufficient

Knowledge Representation

How folksonomies are used to capture knowledge

Overview of Knowledge Representation

• Types of Data• Broad versus Narrow• Tag Distribution• Tag Gardening• User Behaviour• Advantages• Disadvantages

The Tripartite Hypergraph

• 3 types of data– Users/Identity– Resources/Object– Tags/Metadata

• 3 types of graphs– User-Tag-Resource– User-Tag-User– Resource-Tag-Resource

Source: http://www.preoccupations.org/2007/10/thomas-vander-w.html

User-Tag-Resource Graph

• Answers the question “Which resources relate to which user?”

• Useful for PKM and browsing through interesting users’ resources

User

Tag

Resource

Tag

Tag

Resource

Resource

User Tag

User

User-Tag-User Graph

• Answers the question “Which users are similar?”• Useful for finding users with similar interests• Similarity can be measured by connected edges

User

Tag

User

Tag

Tag

User

User

Tag

Very similar users (e=2)

Resource-Tag-Resource Graph

• Answers the question “Which resources are similar?”• Useful for finding related resources• Similarity can be measured by connected edges

Tag

Resource

Tag

ResourceTag Tag

Resource

Resource

Tag

ResourceResource

Highly related resources! (e=2)

Broad Folksonomies

• A resource can be tagged with the same tag more than once– E.g. del.icio.us, CiteULike, Connotea,

Bibsonomy– Tend to be link-based resources

• Can calculate tag frequency per item

• Can enable tag recommender systems

Source: Thomas vander Wal, 2005

Narrow Folksonomies

• A resource can be tagged with a certain tag only once– E.g. flickr, Amazon, YouTube– Tend to be non-textual resources– Resources are inherently unique– Duplicates cannot be detected easily

• Tag occurrence for a resource is either 0 or 1

Source: Thomas vander Wal, 2005

Tag Distribution

• Tends to follow the “Power Law” (drops off exponentially)• Long Tail tags tend to be either useless (personal, synonyms, general) or high

value discriminators

Tag Gardening

• Is the attempt to address tagging problems, such as:– Synonyms (dog, doggy, dogs)– Multilingualism (dog, chien, Hund, perro)– Homonyms (jaguar[cat], jaguar[car])– “Spagging”– Semantic Enrichment (dog is a mammal, poodle is a type of dog,

london and paris are cities)– Personalisms (toread, willbuy, cmn5150)– Misspellings and orthographic variation (uottawa, u-ottawa, u_ottawa,

uotawa)• Must be either:

– User-guided and personal– Community-wide and automatic but invisible

Summary of Advantages

• Authentic Language• Actuality/Neologisms• Multiple interpretations• Cheap indexing – distributed workload• More taggers, better effect – scales well• Identify communities and “small worlds”• Recommendation systems• Familiarize users with indexing system• Faster than classifying in a taxonomy• Good user recollection

Summary of Disadvantages

• Lack of a controlled vocabulary• The context of indexing is lost• Languages are mixed• Hidden relations are unexploited• Spam tags, user-specific tags, unclear keywords• Resources are indexed as a whole• Social character of tags is mostly invisible• Cold start problem

Information Retrieval

How folksonomies are used to retrieve information

Retrieval with Folksonomies

• Search– Works much like full-text search– Puts more weight on tag hits

• Browse– Filter by tag– Uses tag clouds and other tools– Allows for “serendipitous” discovery

• Visualize– Discover patterns in tags

Tag Filtering

• Tag filtering is the mechanism for filtering a list of resources by tag– Mine, a person’s or the community’s

• Usually assume AND relation between tags• Can be implemented with clicks-only or text• Could support more advanced filtering– e.g. newyork & (cats | dogs)

Searching on del.icio.us

Browsing on Diigo

Visualizing del.icio.us with Delicious Soup

Topigraphy

Source: Fujimara, 2008

Concluding Remarks

With applications to Knowledge Management

Folksonomies and KM

• Familiarization with tags• Recommender systems

• Adding tags to resources

• Information retrieval via tags

• Tag clouds, tag search• Visualization tools

• Tag gardening• Automatic processing

Combination Internalization

SocializationExternalization

Folksonomies and Ba

User Issues • Insight into community

mind via tag clouds, visualizations, recommender systems

• Promotion of “tagiquette”• Leveraging selfishness• Integration into traditional

taxonomies

Technical Issues• Intra- and inter-linguistic

issues• Inter-platform issues• Spam detection• Fair relevance rankings• Integrated visualization

tools

How can the environment (ba) contribute to the management of knowledge?

Conclusion

• Folksonomies are a powerful, and sometimes necessary, way of managing Web 2.0

• Functionality, not an application itself• Can complement traditional techniques, like ontologies,

hierarchies, full-text search, etc…• Success depends on:

– Number of users– Quality of implementation– Suitability of resource for tagging– Automatic tag management algorithms– Unsuitability of alternative classification and retrieval mechanisms

References• Fujimara, K. “Topigraphy: Visualization for Large-Scale Tag Clouds” (2008),

WWW2008.• Nonaka, I. “The Concept of ‘Ba’: Building a Foundation for Knowledge Creation”,

California Management Review, Vol. 40, No. 3, Spring 1998, p. 40-54.• Peters, Isabella. “Folksonomies: Indexing and Retrieval in Web 2.0” (2007), De

Gruyter.• Peters, Isabella. “Folksonomies Indexing Und Retrieval In Bibliotheken” (2010).

Retrieved from http://www.slideshare.net/Isabellapeters/folksonomies-indexing-und-retrieval-in-bibliotheken

• Peters, I. & Weller, K. “Tag Gardening for Folksonomy Enrichment and Maintenance” (2008). Retrieved from http://www.webology.org/2008/v5n3/a58.html

• Smith, G. “Visual Folksonomy Explanation” (2005). Retrieved from http://atomiq.org/archives/2005/01/visual_folksonomy_explanation.html

• Vander Wal, T. “Explaining and Showing Broad and Narrow Folksonomies” (2005). Retrieved from http://personalinfocloud.com/2005/02/explaining_and_.html

Questions?

Source: Larson, 1987