[zootboy]

I wish this had a "I can't tell" option. A few of the really hard ones I got right, but I'd say it was more of a lucky guess than a genuine ability to discriminate the difference.

[Freak_NL]

Quite. With the odds being 1 to 3 you'll pick the right one when you have to click one at random to proceed, the results get skewed.

[Retr0id]

If you repeat the test a few times, it'll average out.