Text Only allows you to add a screen or slide with only text (and a media file) in your survey/quiz. It will add interaction and personality to your survey/quiz because instead of only asking information Text Only allows you to also give information in return. You can use this screen for all kind of purposes, some examples:
Giving extra information about the subject
Give extra information about a question, about the answer they indicated in the last question (use Skip logic) or about the subject of the survey/quiz in general.
Showing whether or not the quiz question was answered correctly
You can make a screen in case the respondent selected the right answer and one in case he/she selected the wrong answer. By using Skip logic you can show the appropriate screen after the quiz question. This way the respondent doesn't have to wait until he/she completes the quiz to see the correct answers and explanations. (Be sure to remove the previous-button to make sure respondents don't change their answers. You can deselect this feature in tab 2 Design.)
Dividing your survey/quiz in several subjects or chapters
When your survey/quiz contains multiple subjects or chapters you can use a Text Only screen to announce a new chapter/subject.
Creating a conversation in your survey/quiz
Via Skip logic and Piping you can use the answers the respondent already gave immediately in your next questions or screens, this way you can hold a conversation with your respondent. When a respondent already gave you some personal details, introduce yourself as well. Address the respondent by name and add some Text Only screens to tell something about yourself, the company or the research.