Trust and Semantic Web Technologies
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Transcript of Trust and Semantic Web Technologies
Trust and Semantic Web Technologies
Chris McConnell
April 4, 2006
Two Ways to think about Trust
• Trust in terms of Web Services
• Trust (or reputation) on the read/write Web.
Trust and Web Services
• Trust sits atop Web Services stack
• Web Services technologies
• Needed to protect against malicious users, fraud, flaky business partners.
• Currently, no standard exists for trust in Web Services, so research is speculative.
How could trust be implemented?
• Most articles suggest PKI implementations for authentication.
• As Daconta suggests, current authentication strategies are designed for 1:1 relationships.
• Web Services rely on complex relationships between services (UDDI, WSDL, APIs) more complex than 1:1
Additional Barriers to Trust
• As several authors point out, keys are keys and not users.
• Technological solutions do not guarantee that users are who they say they are.
• Perhaps the most difficult social construct to implement in software.
An RDF approach to Trust
• Uses FOAF and PKI to establish relationships for trusted interactions online.
• Used to sign RDF documents and establish
• Uses a third party to authenticate keys.
Trust and Web 2.0
• Issues of trust in a more explicitly social sphere.
• The “read/write Web” requires trust - or at least reputation” in order to maintain integrity of information or discussion.
• In these cases, it’s not a matter of keeping things private, but instead getting assurance about the quality of public information.
Reputation
• Reputation is based on feedback from other users.
• In offline world, reputation is generally informal
• Online, reputation can be informal or formal.
A formal “Web 1.5” reputation system
• Slashdot uses a “karma” system to rate the reputation of users.
• When users leave comments on entries, these comments can be numerically rated by moderators.
• The sum of these moderation scores determines “karma.”
• Users must reach a particular karma threshold before they can get moderation privileges.
Why was this system developed?
• Slashdot discussions rapidly grew out-of-hand, filled with junk posts, spam, and flamebait.
• Comment ratings allow readers to filter out only the best comments.
• Moderation privileges first went to users known by administrators, then randomly chosen users, until finally settling on current karma system.
Problems with this System
• Initially karma was represented as a numerical value.
• Some users became obsessed with karma: “karma whores”
• New commenters are often ignored, alienated in the moderation system.
• Replicates existing Slashdot attitudes, a self-reinforcing system.
Reputation on Wikipedia• Wikipedia does not have a formal
reputation system like Slashdot.
• Leaders of the project want to encourage as much participation as possible.
• Relies on informal reputation. Contributions to individual articles, participation in Wikiproject, talk pages.
• Vandals can be banned, have their user accounts frozen
Issues for Wikipedia
• Information quality: How can we know this is good information if we don’t know the users?
• Allows anonymous edits, can encourage vandals.
• “Given enough eyeball…”• Reputation is an ancillary issue if many
people are checking pages.
Seigenthaler Incident
• Article on journalist John Seigenthaler accused him of participating in the JFK assassination.
• Posted by an anonymous user.• Article went unnoticed until Seigenthaler
publicized the story in the mainstream media.• Wikipedia response: barring anonymous
users from creating new articles.
Other Ongoing Issues
• Political staffers editing the boss’ article to remove unflattering information.
• Adam Curry editing “Podcast” article to make it more favorable to him.
• Articles that receive little attention can have errors that go unnoticed for long periods.
Future of Trust on Wikipedia
• Jimmy Wales has said publicly that he does not believe the project needs a Slashdot-style
• To improve trust, he says review processes will be expanded.
• Create “gold” and “dev” versions of Wikipedia.
Other Issues of Trust on Web 2.0
• del.icio.us: what happens when spam hits a critical mass on social bookmarking systems?
• Astroturf/FUD blogs. How can blogs be trusted beyond informal social reputation?
• Gaming Digg, etc.
Discussion