Partial answers are designed for checkboxes where respondents can select more correct answers for the same question. You can add two different types of partial answers on your online quiz: with deduction or without deduction.
You’ll find them in the Settings → Advanced section of your form. By ticking the option Enable partial answers, you’ll need to select one of them to use for your online quiz.
Both of these options calculate the success rate in percentage of each question after submission. Given that an unchecked incorrect answer is considered a correct choice, it will receive the same amount of percentage as a correct answer. This means if correct answer A is checked and incorrect answer B is not, both of them are worth the same.