
Unrepresentative Sample
Definition:
The sample used in an inductive inference is relevantly
different from the population as a whole.
Examples:
 To see how Canadians will vote in the next election we
polled a hundred people in Calgary. This shows conclusively
that the Reform Party will sweep the polls. (People in
Calgary tend to be more conservative, and hence more likely
to vote Reform, than people in the rest of the country.)
 The apples on the top of the box look good. The entire
box of apples must be good. (Of course, the rotten apples are
hidden beneath the surface.)
Proof:
Show how the sample is relevantly different from the
population as a whole, then show that because the sample is
different, the conclusion is probably different.
References:
Barker: 188, Cedarblom and Paulsen: 226, Davis: 106
26 May 1995
