What does a screener survey help determine in a research study?

A screener survey is primarily used to identify whether potential participants match the specific criteria that researchers have set for a study. This is crucial because having the right participants who fit the desired demographics, behaviors, or experiences is essential for obtaining valid and reliable data. By using a screener survey, researchers can filter out individuals who do not meet these characteristics, ensuring that the study sample is appropriate for the research goals.

The other options, while they touch on important aspects of participant selection, do not directly capture the primary goal of a screener survey. For instance, assessing willingness to participate is more about recruiting participants, rather than fitting the study's criteria. Understanding the questions pertains more to clarity and comprehension, which isn’t the primary focus of a screener survey. Knowledge about the topic may be relevant, but it is not the main objective of determining the suitability of participants for the study. Therefore, matching participants to desired characteristics is the central function of a screener survey.