Researching my health statistics class, and found this great walk-through of the issues of sensitivity and specificity in medical test design and interpretation. Clear, easy to read, and suitable for everyone.

Everyone that gets medical tests done or will get medical tests done (which, let’s face it, is everyone) should be familiar with this stuff, but it’s often hard to visualize. The author’s technique for representing this makes it wonderfully simple. Click through!


If you are interested in these issues, Kaiser Fung’s Numbers Rule Your World has a great discussion of how they relate to the sham that is steroids testing in sports.

The best book on health statistics I have read is Know Your Chances. For some reason there is a free PDF of it here. It’s short, you can read it in an afternoon, and it’s one of the most useful things you could spend your time on, honest.

I’ve been playing around with cognitive disfluency in slide design for my class lately, trying to solve a conundrum.

The problem is this — we know from research that reading materials that introduce “desirable difficulties” (such as presenting information in a difficult to read font) are recalled better than reading materials with a cleaner, more fluent presentation. This has been referred to as the “Comic Sans Effect”, after the notoriously hard to read font that is also apparently one of the more memorable. But the research shows that anything which disturbs fluency can have positive effects on recall — printing pages with a low toner cartridge, or producing deliberately bad photocopies.

(There’s a lot of caveats to this research, which I’ll deal with later — particularly around the issue of whether we are testing “difficulty” or “novelty”, but also it is a relatively new finding and it’s unclear how it transfers to something like slide design…) 

The problem is there’s a natural tension between your need as a presenter to have your slides represent you as a professional, and your desire to introduce desirable difficulties into slide-reading. The slidesets linked below represent my attempt to strike that balance. They are heavily influenced by mid-90s graphic design and perhaps also by Leigh Blackall’s presentation style from five or six years ago (Leigh’s slides in that 2006 Networked Learning presentation seared themselves into my brain forever, a perfect example of this working well). 

Anyway, here’s some attempts by me to do this. Viva disfluency!

Association & Causation

Observable/Unobservable, Inference, and Claims



I don’t think you can call it remediation anymore when 1/3 of your students require it. At some point the problem is not the students or the high schools, but that we’ve built a higher education system based on false assumptions about who our students are and what they have when they get here.

Our failure isn’t that the students need to be remediated. Our failure is our misaligned priorities require that we call it “remediation”.