Sample Size Matters

The technical bit…

In making use of statistical probability principles in our direct marketing, we are trying to infer from one performance the likelihood of future performance.

But predictions based on test results are conditional on all other factors remaining the same, which is plainly not possible.

So any conclusions arrived at by using our Sample Size Matters ready-reckoner must be treated with a degree of caution and subjective judgement.

“Size matters” because the smaller the sample group from which we are trying to predict behavour, the less certain our conclusions are going to be.

Click on the question on the right that you want help with.. click on the Sample Size Matters button to return to this page at any time.

Our ready-reckoner uses a common statistical probability formula based on a 95 percent confidence level * to answer the three FAQ’s to the right.

[* 95% confidence level = “95 times out of a hundred this will be the case, all other factors being equal”]