Open-ended questions, in which participants write or type their responses, are used in many areas of the behavioral sciences. Although effective in the lab, they are relatively untested in online experiments, and the quality of responses is largely unexplored. Closed-ended questions are easier to use online because they generally require only single key- or mouse-press responses and are less cognitively demanding, but they can bias the responses. We compared the data quality obtained using open and closed response formats using the continued-influence effect (CIE), in which participants read a series of statements about an unfolding event, one of which is unambiguously corrected later. Participants typically continue to refer to the corrected misinformation when making inferential statements about the event. We implemented this basic procedure online (Exp. 1A, n = 78), comparing standard open-ended responses to an alternative procedure using closed-ended responses (Exp. 1B, n = 75). Finally, we replicated these findings in a larger preregistered study (Exps. 2A and 2B, n = 323). We observed the CIE in all conditions: Participants continued to refer to the misinformation following a correction, and their references to the target misinformation were broadly similar in number across open- and closed-ended questions. We found that participants' open-ended responses were relatively detailed (including an average of 75 characters for inference questions), and almost all responses attempted to address the question. The responses were faster, however, for closed-ended questions. Overall, we suggest that with caution it may be possible to use either method for gathering CIE data.
Keywords: Closed-ended; Continued influence effect; Misinformation; Open-ended; Response formats; Web-based.