Tagging in Social Networks


Session Outcomes

At the end of the session participants will be able to:

  • Understand the difference between taxonomic and folksonomic classification
  • Understand how tagging can be used to manage, categorise and share online resources
  • Understand social software tools and how tagging is utilised
  • Use 3 web2.0 services which utilise tagging to oragise and share resources
    • Social bookmarking del.icio.us
    • Photo Sharing - Flickr
    • Blog search engine - Technorati
  • Understand the relationship between tagging and RSS feeds

What is Tagging?

Tagging is a method of categorisation whereby key words are assigned to web based resources by users of social software services such as social bookmarking or photosharing sites. Each user "tags" the resources arbitrarily according to their own personal preferences. Items may have multiple tags which may or may not correspond to other users tags. Because users assign their own tags, which may not necessarily correspond to other users, the system is potentially ambiguous and anarchic. For example I may tag “apple” for a resources related to a brand of computer however another person may be assigning it to a type of fruit.

This practice of social groups collaboratively categorising resources is known as folksonomy and differs from the more formal model of a predefined hierarchal model of classification know as taxonomy such as the Dewy Decimal system used in library's.

external image spaceball.gifexternal image spaceball.gifTaxonomy - The science of classification
  • From the greek verb:
    • Taxis = "to classify"
    • Nomos = "law, science, economy"
  • Hierarchical-enumerative top down tree like structure
  • Hierarchies designed and maintained by experts
  • Repositories cataloged by experts eg. libraries
  • Structure imposed on the world of objects
  • Centralised classification

Folksonomy - Social classification
  • Folk + Taxonomy meaning that it emerges from the people
  • Open democatic system
  • Constantly evolving based on user interactions and consensus
  • tags capture the social fabic at that moment in time
  • Structure is an emergent property
  • Well suited to rapidly changing heterogeneous information sources such as the internet and social networks
  • Distributed classification

Emanuele Quintarelli, Folksonomies: power to the people, 2005

Social Software & tagging

external image 4921613_e07c9d03d7_m_d.jpg

Photo by jbum

Tagging or the folksonomic process of assigning keywords to items has become synonymous with what is referred to as social software. Social software are web based services which allow users to form social networks online. Although heterogenous in their service provision they all have some common charateristics.

Social software has some or all of the following characteristics:
  • Easy content creation
  • Collaborative content creation
  • Ability to share content with others (often via RSS feeds)
  • Makes it easy to find other users with similar interests
  • Tools for forming online communities

Examples of Social Software

Three of the best known examples of social software using folksonomies are probably Flickr, Del.icio.us and Technorati.


Flickr is a social software tool which allows users to store and share thier digital photo's online.

Each photo is tagged with one or multiple keywords. Although photo access can be restricted to ones friends and family, the overwhealming number of photos are shared publicy, often under a creative commons licence.


Uses for flickr

Storing and cataloguing you own photos online so they can be accessed over the internet from multiple computers
  • Sharing photos with friends and family
  • Group colloboration, for example a common tag was used by NSW LearnScope teams in 2005 "nswlearnscope2005"
  • Finding and using photos with appropriate creative commons licence for educational purposes
  • Artistic expression and exchange through flickr groups
  • Mashps using flickr API eg. flickrgraph, retrievr, Spell with Flickr
  • Creating slides shows within Flickr
  • Easy and effective way for teachers and students to upload and share visual resources
  • Redistibute rss feeds using rss ie flickr badges on blogs, see example below on this wiki


Initially developed by Joshua Schachter as a simple web page listing bookmarks with annotations, Schachter then decided to make these available on a web server so that friends and others could also view them. From there, it was but a small step to hosting others' lists, and so the social bookmarking tool del.icio.us was born.

del.ico.us is what is commonly referred to as a social bookmarking service. Users to the service intially store bookmarks which they find useful and would have previously stored locally in the browsers favorites.

Uses for Del.icio.us
  • The primary use of del.icio.us is to store your bookmarks online, so you can access them from anywhere.
  • Group colloboration, for example a common and agreed upon tags are used by a group to categorise and share web resources.
  • Ling and Tag rolls via RSS
  • Mashps using Del.icio.us API eg. http://www.digglicious.com/
  • Podcasts using the playtagger tool built into del.ico.us for example the AFLF CoolConnections conference where all the mp3 recordings were tagged "coolconnections05podcast"

RSS feeds for tags

Social software services which utilise tagging TYPICALLY provide rss feeds for each tag facilitating redistribution and mashups. Adding flickr feeds and del.ico.us links rolls is a common way to of fostering community within online social networks. RSS feeds from tags also allows syndication via rss aggregators. ie. Students could subscribe to the class tag to keep track of resources.

Selected Links

Entry on "Tags" in Wikipedia, the free encyclopedia

Entry on "Folksonomy" in Wikipedia, the free encyclopedia

A social analysis of tagging (or how tagging transforms the solitary browsing experience into a social one) - An informative essay by Rashmi Sinha January 18, 2006

Ontology is Overrated: Categories, Links, and Tags - Clay Shirky, spring of 2005

Folksonomies - Cooperative Classification and Communication Through Shared Metadata - Adam Mathes, December 2004

Folksonomies: power to the people - by Emanuele Quintarelli

Knowledge Sharing with Distributed Networking Tools - Sean Fitzgerald & Leigh Blackall, 2005

The latest 10 resources tagged in del.icio.us with "TAA40104"

    The latest 5 photos tagged in nswlearnscope06 with "tagging"