Respondent Conditioning in Online Panel Surveys: Results of Two Field Experiments

In this article, we investigate changes in survey reporting due to prior interviewing. Two field experiments were implemented in a probability-based online panel in which the order of the questionnaires was switched. Although experimental methods for studying panel conditioning are favorable, experiments in longitudinal studies are rare. Studies on conditioning demand additional resources and might influence respondents’ answers. Panel conditioning is mostly associated with measurement errors. However, the discussion that sees it exclusively as a negative phenomenon is not comprehensive. Learning the rules of the interview may lead to increases or decreases in data quality (advantageous vs. disadvantageous conditioning). Overall, little evidence of advantageous conditioning and no disadvantageous conditioning is found. Apart from this reassuring finding, this aricle advances the field by using propensity score weighting to account for attrition and other confounding factors and by using paradata to evaluate the plausibility of alternative explanations of panel conditioning.