Define the Objective: Clearly outline what you aim to learn or achieve from the email campaign or experiment. Determine Effect Size: Identify the minimum effect size that is considered practically significant for your objectives. Set Alpha Level: Choose the significance level (commonly 0.05) to control the probability of a Type I error. Determine Power Level: Typically set at 0.80 or 80%, this determines the probability of correctly rejecting a false null hypothesis, thus controlling for a Type II error. Calculate Sample Size: Use statistical software or power analysis calculators to determine the required sample size based on the inputs above.