Use Additional validation to perform additional or more specific validation beyond making a piece of content required or by using question display logic. When its logic is met, Additional validation displays a validation error message, and survey takers are not allowed to navigate past the page until complying with the validation requirements.

For example, you can use Additional validation to present a custom error message, like instructions to the survey takers when they omit to enter their first name.

Additional validation needs a rule to for the validation and the message to be displayed. In the following example, survey takers must answer Yes to the question Is customer follow-up required? and left Customer First Name blank to trigger the Additional validation.

For more information, see Survey content.