Margin of Error

Definition:

The margin of error indicates the level of random sampling error generated by drawing a sample as opposed to conducting a census. It is expressed as + or – of the statistic and falls as the sample size rises (it’s highest at 50%)..

It can be calculated by multiplying the critical value by either the standard deviation or the standard error of the statistic. P is the percentage that the sample is seeking to measure (e.g. conversion rate of 6%).

Image of Margin of Error formulas

Resources:

 

Conversion marketing – Glossary of Conversion Marketing.

Over 300 tools reviewed – Digital Marketing Toolbox.

A/B testing solutions – Which A/B testing tool should you choose?

Types of A/B tests – How to optimise your website’s performance using A/B testing.