The ultimate goal of testing and optimization should not be to simply achieve a lift in revenue or an increase in email addresses acquired. Instead, the goal of an experiment should be to achieve a learning; to gain an insight into the mind of the donor.
Before we can analyze the results of an experiment, we first need to determine that the results are both valid and that a large enough sample size has been met. This page will help you ensure your experiments meet both of these qualifications.
Validating your experiment is done in two simple steps.