What does "unrepresentative sample" mean

Krysoraa

I came across this issue when I was doing June 2020 Section 2 Question 25. I thought unrepresentative sample applied because the sample was on [test subjects before experiments] and the conclusion was on [test subjects after experiments]. But a few people have told me that the "unrepresentative sample" answer choice is only for statistically unrepresentative things, like only interviewing 10 people when the population is 100,000.

offy0c-1-1

Yes, I think you have it right. The unrepresentative sample (US) is when they use some sort of bias to test their results. The idea is not just limited to a limit of individuals that they use as the US can also be used when they have gotten a biased group or bias survey results; i.e. selecting individuals from a certain region that have a particular preference (voting proclivity or food preference) in order to say that individuals share this element. You should also be weary bc there are instances in which the flaw questions may appear that this sort of error is present when it is not, because the lsat authors have protected themselves against this sort of bias when they say they gathered their results "from a representative group sample". So, there will be an indication when they get rid of the possibility of having this error when phrases (like the one mentioned) are present.

Hope this helps!

troysch1

Typically, if the question is meant to test for this, the stimulus will go out of its way to flag something about the sample to you (ie 'a sample of 5 individuals' 'a sample of people ages 5-15' etc). If the question just says they ran an experiment/study, but is silent as to what the population was, overwhelming odds are the flaw is not related to the sample being unrepresentative.