This week's definition of Occam's Razor is that the simplest explanation is usually the correct one. As I've been taught, though, that's actually an oversimplification of the rule - and one that actually renders it useless, since 10 people will give you 11 opinions about what the simplest explanation is.

I was taught the rule is "The explanation that requires the fewest assumptions of facts-not-in-evidence is usually the correct one."