Understanding the following Verdict concepts can help you implement experiments and discuss them with peers.
Experiments are defined in app/experiments and encapsulate the details of the test including metadata such as the name, description or owners, as well as any qualifiers or the groups available in the test.
Qualifiers are methods that take two parameters, subject and context. They return true if the subject can take this experiment, or false if the subject is not eligible. Experiments can have multiple qualifiers which are evaluated in succession. If a qualifier returns false, no further qualifiers are checked.
Examples of qualifiers might be subjects that:
- Originate from certain browsers or devices
- Have a specific
Accept-Languageheader - Have added items to their cart.
A subject is the thing that will be qualified, and if successfull, assigned to a particular group. For example, a subject might represent a user.
Each experiment will have two or more groups, usually a control group and a test group. Qualified subjects are assigned to one of the groups in the experiment.
An assignment occurs when a qualified subject is placed into a group. Assignments are persisted so repeat visits by the subject skip qualification and re-assignment and simply returns the existing assignment.