Wednesday, February 19, 2014

Facebook Meets Florence Nightingale and Enrico Fermi

Highlighting Facebook's mistakes and weaknesses is a popular sport. When you're the 800 lb gorilla of social networking, it's inevitable. The most recent rendition of FB bashing appeared in a serious study entitled, Epidemiological Modeling of Online Social Network Dynamics, authored by a couple of academics in the Department of Mechanical and Aerospace Engineering (???) at Princeton University.

They use epidemiological models to explain adoption and abandonment of social networks, where user adoption is analogous to infection and user abandonment is analogous to recovery from disease, e.g., the precipitous attrition witnessed by MySpace. To this end, they employ variants of an SIR (Susceptible Infected Removed) model to predict a precipitous decline in Facebook activity in the next few years.

Channeling Mark Twain, FB engineers lampooned this conclusion by pointing out that Princeton would suffer a similar demise under the same assumptions.

Irrespective of the merits of the Princeton paper, I was impressed that they used an SIR model. It's the same one I used, in R, last year to reinterpret Florence Nightingale's zymotic disease data during the Crimean War as resulting from epidemic spreading.

Another way in which FB was inadvertently dinged by incorrect interpretation of information—this time it was the math—occurred in the 2010 movie, "The Social Network" that tells the story of how FB (then called Facemash) came into being. While watching the movie, I noticed that the ranking metric that gets written on a dorm window (only in Hollywood) is wrong! The correct ranking formula is analogous to the Fermi-Dirac distribution, which is key to understanding how electrons "rank" themselves in atoms and semiconductors.

"The reports of my death have been greatly exaggerated."

Tuesday, February 18, 2014

Guerrilla Classes in March 2014

The upcoming GBoot and GCaP training classes are your fast track to enterprise performance and capacity management. You can now register entirely online using either your corporate or personal credit card.

New topics include:

  • The effect of think-time settings in load tests
  • Closed vs. open workloads in load testing

Classic topics include:

  • There are only 3 performance metrics
  • How performance metrics are related to each another
  • How to quantify scalability with the Universal Scalability Law (USL)
  • IT Infrastructure Library (ITIL) for Guerrillas
  • The Virtualization Spectrum from hyperthreads to hyperservices

Entrance Larkspur Landing hotel Pleasanton California

As usual, all classes are held at our lovely Larkspur Landing Pleasanton location in California. Attendees should bring their laptops to the class as course materials are provided on a flash drive. Larkspur Landing also provides free wi-fi Internet in their residence-style rooms as well as the training room.