when you conduct a survey, how do you know how many people is enough?

Question

when you conduct a survey, how do you know how many people is enough?

In: Other

Answer 1

The first part is statistical significance and margin of error. There is a formula that will help you find the sample size needed given a population size, based on what margin of error you want.

There’s also convenient lookup tables.

For lots of surveys, that’s enough. But if you want to be more accurate given demographics, you would use stratified sampling.

This involves dividing the population into distinct subgroups (strata) that share similar characteristics, and then randomly sampling from each stratum proportionally to their subset of the population.

So let’s say one stratum is “people who agree Die Hard is a Christmas movie” and it’s 78% of all people. When we figure out our sample size for significance, we’ll need to make sure 78% of those people are the Die Hard folks.