• Search, reputation/trust networks, and PageRank

    • Scholarly peer review: earliest practice 1665 in Royal Society; developed in 18th and 19th centuries; commonplace starting in 20th

    • Submitting scholarly papers:

      • Ideal goal: Want information to be as freely as possible

      • Journals

      • Conferences

      • Preprints

        • “Anyone” can post their scientific paper (even more fast paced); however, these papers are not peer reviewed.

    • Peer Review Process:

      • Single Blind

      • Double Blind

      • Conflict of Interest

    • Evaluating scientists: But how to identify/measure/rank scientific achievement, excellence?

      • Number of “published” papers.  Limitations?

      • Number of citations.  Advantages and limitations?

      • h-index by Jorge E. Hirsch in 2005.  Advantages and limitations?

    • Search engines: AltaVista search engine (1995), Google takeover, Yahoo purchase (2003) and shutdown (2013)

      • Concept: pages “vote on” each other

        • But how much “voting power” does each page wield?

        • What’s wrong with 1 page 1 vote?

      • Page’s voting power weighted by reputation

        • But reputation depends on voting power … circular!

      • Solution: iterate with decay or resistance factor

        • Illustration: random surfer (Markov chain) model

      • PageRank as optimization-based linear programming

    • Twitter as an emergent influence network

      • Influence metrics: Indegree, Retweet, Mention influence

        • Briefly-mentioned alternate PageRank-like metric

      • “We limited the study duration because popular keywords were typically hijacked by spammers after certain time”

      • “most influential users hold significant influence over a variety of topics.”

      • “it is substantially more effective to target the top influentials than to employ a massive number of non-popular users in order to kick start a viral campaign”

      • “influence is not gained spontaneously or accidentally, but through concerted effort”


Post-lecture blackboard snapshot 2019:



Last modified: Thursday, 8 October 2020, 16:17