Four short links: 30 November 2011
Crypography Illustrated, Hollywood Futures, Machine Learning Mastery, and Analytics Assumptions
- An Illustrated Guide to Crypographic Hashes — exactly what it says: learn how hashing works and how you’d use it for passwords, digital signatures, etc.
- The Age of Fanfiction — We live in a time where copyright means very little to younger people, and it’s not just because they want free movies or free music. More than that, they want to be able to play with the amazing toys that they’ve been given by filmmakers and comic book writers and TV creators, and they want to do so without the constraints that copyright creates. Eloquent and thoughtful piece on what this means for Hollywood and how “the Age of Fanfiction is reflected in what Hollywood’s making. (via Sacha Judd)
- How Khan Academy is Using Machine Learning to Assess Student Mastery — it is bloody hard to know when a student has mastered a subject, both for real live teachers and for roboteachers like Khan Academy. This is a detailed discussion of a change in assessment within Khan Academy. if we define proficiency as your chance of getting the next problem correct being above a certain threshold, then the streak becomes a poor binary classifier. Experiments conducted on our data showed a significant difference between students who take, say, 30 problems to get a streak vs. 10 problems right off the bat — the former group was much more likely to miss the next problem after a break than the latter.
- In Which I Declare Four Things My Probability Class is Not About — a reminder of the assumptions we make when we use numerical analysis to understand a problem.