Kaliya started the day with a call for anyone else who wanted to create new sessions and then did a "spectrogram." She put a long piece of tape on the floor and asked questions where people arrayed themselves along the spectrum represented by the tape. She interviewed people at spots on the tape. A good way to get a feel for how the group is thinking about some things.
I did my session on reputation and showed off the reputation system we built in my 601 class last semester. Generally well received and good comments.
Chris Allen led a session on the notions of reputation and collective choice.
In collective choice, there are three primary actions: selection, opinion, and comparison. Selection happens by voting, deliberation (Robert's Rules), and consensus. Opinion systems mainly rely on polling. Comparison happens by ranking, rating, markets, and reputation.
Which bring us to reputation. Reputation can be used for collaborative filtering, collaborative sanctioning, and threshold maintenance. Negative reputation can be problematic. Altruistic punishment is a way of getting around that.
Reputation changes over time. Reputation accumulates. Timestamps on transaction are important. Disassociating from past choices is important. Who's not my friend any more?
Chris has been looking at attack categories for reputation.
- Shilling attacks (using a shill) can add to a reputation with no substance, yielding high positive ratings. Called "astroturf" in some circles--fake grassroots.
- Spamming attacks can lead to excess bad results. Also called "griefing."
- Whoring (as in "karma whoring" on Slashdot). You do things right right for a time in order to build up a reputation which you exploit later. Sell a bunch of cheap books on Amazon and then use the good reputation to rip someone off on a single large transaction. A better word for this might be "Stinging."
- Collusion (Chris called this "faking") is people working together to build a false reputation.
- Coercion & retaliation
- ID attacks
- Flooding attacks
There were some great sessions and the workshop seemed to have given most people some new things to talk about. We're contemplating what to do for the next workshop in the Fall. We'll be doing a short event just before DIDW on September 11. THat will be a 6 hour event and attendees will get a break on DIDW entrance fees.
We also want to do a longer event later in the fall. We've contemplated doing an event on the East coast in November, but I'm inclined to stick with the West Coast because of the energy that's being generated in the events that we've had so far. If you have ideas, contact me or Kaliya and let us know.