1. The Credibility of Digital Identity Information on the Social Web: A User Study Matthew Rowe Organisations, Information and Knowledge Group University of Sheffield

2. Outline Problem: Increased reliance on digital identity information Motivation: Need for assessing the credibility of digital identity information Digital Identity The tiers of identity information Comparing Digital and Real-World Identities User study of Social Web users Findings from the Study Conclusions

3. Problem The World Wide Web has evolved from a Web of anonymity into an accountable Web Users are able to interact online with Web platforms Publish their thoughts and musings on blogging platforms such as LiveJournal Upload videos onto Youtube Share photos on Flickr Chat with friends on MySpace All of the above allow users to construct bespoke online personas So called “Digital Identities” Shaping how they wish to be perceived by others in an online environment

4. Motivation Digital identity information from Social Web platforms is used by a range of 3rd party applications and services: Dopplr uses social network information from user profiles to share travel arrangements and planned trips Google’s Social Search uses identity information to affect search listings Identity management services have begun using digital identity information Social Web platforms to support automated identity disambiguation techniques Employers use Social Web platforms to perform lateral surveillance of potential and current employees The increased reliance on digital identity information from Social Web platforms requires an assessment to be made of the credibility of this information To what extent is real identity information mirrored in a digital space?

5. Digital Identity The Oxford dictionary defines identity as: “the fact of being who or what a person is” and… “the characteristics of defining this” A person’s identity is comprised of a set of attributes which makes them unique Digital Identity reflects this, however in an online space the these attributes can be customised and tailored by the user The functionalities and feature sets provided by Social Web platforms facilitate this alteration Users can construct profiles containing their biographical information (name, address, email) along with their social network information

6. Digital Identity Digital Identity can be divided into 3 tiers: My Identity: persistent identity information such as name, date of birth and genealogical relations Shared Identity: information which is susceptible to change such as social network information Abstracted Identity: identity information derived from groupings and demographics (Ploderer et al, 2008) states that self-promotion motivates web users to create a profile (Lampe et al, 2006) found Social Web users to search for and interact with those people which they knew offline The social network which a web user maintains is a powerful tool in establishing a unique identification of the person This is used by identity disambiguation techniques to confirm person references on the Web

7. Comparing Digital and Real-World Identities Social network information from the shared identity tier provides a means of quantifying the similarity between digital and real-world identities: To what extent is real identity information mirrored in a digital space? To explore this question a user study was conducted using the Social Web platform Facebook Given that this is the most popular Social Web platform in the UK 22 million users in the UK http://www.clickymedia.co.uk/2009/10/uk-facebook-user-statistics-october-2009/ 50 participants were gathered from the University of Sheffield 25 male and 25 female Age range of 18-45 The experiment was conducted in November 2008

8. Comparing Digital and Real-World Identities The user study consisted of 3 stages: Each participant listed their real-world social network Used a web page form with 20 rows, one for each person of the network, containing their name and the relationship type More rows could be added if needed Contains strong-tied relationships (Donath & Boyd, 2004) Each participant’s digital social network was extracted from Facebook Using an application designed for this study Also analysed the behaviour of the the participant: who they appear in photos with and who they share messages with Each participant compared his/her real-world and digital social network Selected participants which appeared in both networks

9. Comparing Digital and Real-World Identities To measure the extent to which digital identity information mirrors real-world identity information the following evaluation measures were used: Relevance Adapted from the information retrieval metric: precision Measures the ratio of strong-tied to weak-tied relationships in the digital social network Coverage Adapted from the information retrieval metric: recall The proportion of the real-world social network which appears in the digital social network

10. Comparing Digital and Real-World Identities Relevance Average relevance measure of 0.23, indicating that 23% of a digital social network contains strong-tied relationships Coverage Ranges between 0.5 and 1, with an average coverage of 0.77 This indicates that, on average, 77% of a participant’s real-world social network appears online Different from findings by (Subrahmanyam et al, 2008) which found only 49% for coverage (they define it as overlap) Possibly due to differing dates when the studies were conducted and the differing countries

11. Comparing Digital and Real-World Identities

12. Comparing Digital and Real-World Identities The covered portion of the real-world social network in the digital network was also analysed, and showed the following: Majority of relationships were with friends (62%) 24% were with family 14% were with coworkers For the different relationship types in the real-world social network 89% of friends were replicated online 73% of family were replicated online 68% of coworkers were replicated online The largest age group in the social network that was covered online was <21 Indicative of the sample used by the study

13. Comparing Digital and Real-World Identities Behaviour of each participant was analysed Assessing who they appeared in images with and interacted with on the platform Results demonstrate a tendency to interact with only a few people frequently And a large number of people rarely The graph forms a power law curve Denoted as the Social Longtail (>15) The longtail contains 92% of strong-tied relationships which appeared in the real-world network listed by participants Suggests that offline interactions and communications are continued online Demonstrated by the number of messages sent and photos in which both people appear

14. Conclusions Credibility of digital identity information is important to many application which rely on such information Findings from the study quantify the significant extent to which web users replicate their real-world identities in an online space Characterised by the large coverage of real-world social networks on an example Social Web platform An insight is provided into the credibility of digital identity information found on the Social Web Behavioural trends demonstrate the continuation of interaction offline in a digital environment The Social Longtail is mainly comprised of strong-tied relationships found offline, driven by frequent interactions The results also provide findings in contrast to (Subrahmanyam et al, 2008) Due to the different domains in which the studies were conducted

15. Twitter: @mattroweshow Web: http://www.dcs.shef.ac.uk/~mrowe Email: m.rowe@dcs.shef.ac.uk Questions? (Donath & Boyd, 2004) - J. Donath and D. Boyd. Public displays of connection. BT Technology Journal, 22(4):71–82, October 2004. (Lampe et al, 2006) - C. Lampe, N. Ellison, and C. Steinfield. A face(book) in the crowd: social searching vs. social browsing. In CSCW ’06: Proceedings of the 2006 20th anniversary conference on Computer supported cooperative work, pages 167–170, New York, NY, USA, 2006. ACM. (Ploderer et al, 2008) - B. Ploderer, S. Howard, and P. Thomas. Being online, living offline: the influence of social ties over the appropriation of social network sites. In CSCW ’08: Proceedings of the ACM 2008 conference on Computer supported cooperative work, pages 333–342, New York, NY, USA, 2008. ACM. (Subrahmanyam et al, 2008) - K. Subrahmanyam, S. Reich, N. Waechter, and G. Espinoza. Online and offline social networks: Use of social networking sites by emerging adults. Journal of Applied Developmental Psychology, 29(6):420–433, November 2008.