Improving Comprehension of Consent Forms in Online Research: An Empirical Test of Four Interventions

Informed consent is a guiding ethical principle when conducting research involving human participants. Yet, consent forms are often skimmed or ignored, jeopardizing informed consent. In two experiments, we test four interventions designed to encourage participants to read online consent forms more carefully. Experiment 1 employed a 2 (length: short or long) by 2 (timing: fixed or free) by 2 (quiz: present or absent) between-participants design. We measured instruction-following and comprehension of the consent form. Results showed that fixed timing and a quiz led to greater instruction-following, but consent form length had no effect. Experiment 2 employed a 2 (length: short or long) by 3 (delivery format: live, audiovisual, standard written) between-participants design. Once again, length had no effect, but both live and audiovisual formats increased instruction-following and comprehension. We recommend that researchers consider using fixed timing, adding a quiz, and/or using alternative delivery formats to help participants make an informed decision.