Your client feels like her emails arent getting a high enough open rate. Currently, 7% of emails are opened. Youve suggested changing the subject heading of the email, and shes asked you to describe, in detail, how you would test whether the new subject is effective.

1. Describe the key concepts behind hypothesis testing and A/B testing
2. Describe how you would structure the test in this case
3. Describe what business action may be taken depending on the result of the test