We Could Even Tools use a small number of session cookies to pass data to/from the form the user can see at the end of a quiz.
If the user has come via another page with a form before the quiz, you can add a couple of lines of code we provide there, and it will store key fields (name and email address) in order to autofill the corresponding quiz form fields if you wish, making it quicker and easier for users to complete the quiz if you already have some of their data in advance. (You can also choose to hide autofilled form fields if you like.)
The quiz tool also stores key details the user has submitted during a quiz (such as their name, email address, and quiz results) so these can be shown on a subsequent page on your website, if you wish. This allows you to pre-fill form fields on petition, donation, or other action pages that follow the quiz, creating a seamless experience for your supporters.
We have also produced some detailed guidance.
Here is some suggested wording for your cookie policy which you may wish to use or adapt:
Quiz functionality cookies
When you take part in an interactive quiz on our website, we use session cookies to carry the information you have entered (such as your name, email address, and quiz results) to the next page in your journey. This means you do not need to re-enter information you have already provided. These cookies are set on our domain only, expire when you close your browser, and are not used for any other purpose. They are classified as strictly necessary for the service you have requested.