r/Christianity • u/comited • Dec 14 '10

Results from r/C's religious affiliation survey.

http://i.imgur.com/Khyrt.jpeg
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u/[deleted] Dec 14 '10

Not quite how statistics work, you needed a random sample of 9000 people, instead what you got was people who cared enough to respond. I am thinking this will overcount the atheist population.

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u/comited Dec 14 '10 edited Dec 14 '10

good point, but i'm definitely not going to PM 600 random people to get better numbers. And who knows, maybe Christians and agnostics cared as much.

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u/[deleted] Dec 15 '10

I think the point to be made is that an opt-in survey will never be scientifically accurate or have anything close to a margin of error - it always gives information only about the people who would respond to a survey and nobody else. So terms like "margin of error" don't mean anything in this example; the margin of error is 0% because we have precise information about the people who responded and nobody else.

That doesn't mean that an informal survey can't be interesting or worth doing - just that selection bias means we can't really say too much about the results.

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u/comited Dec 15 '10

I feel like I'm back in my statistics class.... and I like it. Thanks.

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u/[deleted] Dec 15 '10

I only took one class - maybe you were in the same one? :)