Sandman
Which would be statistically worthless even if we were only talking about one store, which we weren't.

Eric Stevens
Why would it be statistically worthless even for the one store at which the data was gathered?

Sandman
Because it is only one data point. It's like I would ask you if you're feeling good and you complain about a headache and then I use this to conclude that you suffer from headaches 100% of the time.

Eric Stevens
Poor analogy. Actually it's like you visiting me 24 times and one time finding me with a headache. You could then conclude 'Eric Stevens has headaches'.

Sandman
Nope. Out of the 24 body parts I asked you about on the one visit, you reported a headache, so my statistics show that for Eric Stevens, out of 24 body parts, one is always malfunctioning.

Eric Stevens
You haven't studied statistics or probability have you?

That one body part had a headache at the time of your one visit does not mean that it always has has a headache (or 'malfunctioning' as you describe it).