When these techniques involve people, researchers use questionnaires administered in written form or person - to - person, either by personal or telephone interview, or increasingly online. (inc.com)
The study used a survey design with an anonymous self - report questionnaire administered to students (grades 3 — 8) in 11 public schools. (pediatrics.aappublications.org)
A second limitation is that the study relied exclusively on student self - reports to measure substance use outcomes, obtained through a confidential written questionnaire administered in the classroom. (toptierevidence.org)