1. Computer-Mediated Communication
Reputation (Part I)

2. Assignment 1: Group Projects
Grades on Assn 1 were all “A” – we were looking for effort and good discussion with each group.
Assn 2 will be graded in a more traditional way, and we will provide guidelines at least 2 weeks in advance.
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Computer-Mediated Communication

3. From Trust to Reputation: The CMC Trust Paradox:
Online “Certainty”
Interpersonal
Trust
Credit here to Nissenbaum
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Computer-Mediated Communication

4. What are the Solutions to Uncertainty in CMC Environments? (revisited)
Proxies and ‘inferred trustworthiness’
Institutional backing
Closed Systems versus Open Systems
Experiential, often negative-only reputations (not explicit)
3rd party (explicit) reputation
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Computer-Mediated Communication

5. Computer-Mediated Communication
Oh no, lemons!
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Computer-Mediated Communication

6. Information asymmetry: Used cars
After the sale.
Before the sale…
Buyer
Seller
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Computer-Mediated Communication
Images from khulsey.com

7. Computer-Mediated Communication
Avner Grief : Studied Maghribi traders in the 11th century; example of a closed system of trade/exchange.
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Computer-Mediated Communication

8. Open versus Closed Systems
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Computer-Mediated Communication

9. Computer-Mediated Communication
Fear of “exclusion” was key for Maghribi trade coalitions (according to Grief’s work)
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Computer-Mediated Communication

10. Computer-Mediated Communication
Closed System Examples in CMC:
Open Source System
(kernel vs. GUI)
Wikipedia
(You cannot change anything you want? For real??)
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Computer-Mediated Communication

11. Computer-Mediated Communication
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Computer-Mediated Communication

12. Computer-Mediated Communication
“Reputation” systems
Explicit
Implicit
Experience
Ratings by others
Derived from behavior
“Scare quotes” because not all of these are really “reputation.”
Behavior — direct, remembered experience by one user of another. Requires persistent identity; the other two do not as long as reputation score persists.
Implicit — e.g., reply-to-post ratio. Aggregations of behavioral data.
Explicit — users specifically asked to rate the worth or performance of others.
Join Date: Mar 2004
Posts: 22
Direct experience of Behavior
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Computer-Mediated Communication

13. Computer-Mediated Communication+ –
Explicit reputation systems /
Useful when: – Open system – Identity transient – Exclusion impossible
Useful when: – Closed system – Identity persistent – Coalitions, no alternatives
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Computer-Mediated Communication

14. Computer-Mediated Communication
How might different types of reputation systems solve the lemons problem?
11/30/2018
Computer-Mediated Communication