In web surveys, no interviewer is present to clarify question comprehension problems, which can be particularly prevalent among respondents with low literacy skills. Although plain language is used in various contexts to improve text comprehensibility, its use in social science questionnaires has not been investigated to date. Using a…

Probes are follow-ups to survey questions used to gain insights on respondents' understanding of and responses to these questions. They are usually administered as open-ended questions, primarily in the context of questionnaire pretesting. Due to the decreased cost of data collection for open-ended questions in web surveys, researchers have argued…