Ratings, so you know... Answered
I spent a bit of time today looking again at the Instructables rating system, here's what I found:
A single rating lands an Instructable around the 3 mark, there is a huge spike just on the upper side of 3.0. Mean average rating (rather close to Pi) is 3.14
Most ratings seem to be positive, the overall distribution has 68.7% of rated Instructables "above average" (60.5% of all Instructables if you include unrated submissions)
There is a "wave" of ratings heading up towards 4, and a smaller ripple going down towards 2. I see this as some kind of fluid-motion effect like waves on water, but I'd be interested in opinions.
50% of rated Instructables sit between 2.9 & 3.4
Instructables rated above 3.4 are in the top 25%
Instructables rated below 2.9 are in the lower 25%
Note: Rating is essentially a measure of popularity, it is not a linear indicator of quality / value.
Only 31 Instructables are rated above 4.5 (0.1%)
Only 19 Instructables are rated below 1.5, 1 of which is the lowest at 0.99
Only 12% of Instructables are unrated
The rating algorithm is in Rachel's FAQ if you're interested (I probably should have put this in earlier)