An Experimental Study on the Impact of Survey Stakes on Response Inconsistency in Mixed-Worded Scales

Respondent behavior in questionnaires may vary in terms of attention, effort, and consistency depending on the survey administration context and motivational conditions. This pre-registered experimental study examined whether motivational context influences response inconsistency, response times, and the role of conscientiousness in survey responding. A sample of 66 university students in Cyprus completed five psychological scales under both low-stakes and high-stakes instructions in a counterbalanced within-subjects design. To identify inconsistent respondents, two index-based methods were used: the mean absolute difference (MAD) index and Mahalanobis distance. Results showed that inconsistent responding was somewhat more frequent under low-stakes conditions, although differences were generally small and significant only for selected scales when using a lenient MAD threshold. By contrast, internal consistency reliability was slightly higher, and response times were significantly longer under high-stakes instructions, indicating greater deliberation. Conscientiousness predicted lower inconsistency only in the low-stakes condition. Overall, high-stakes instructions did not substantially reduce inconsistent responding but fostered longer response times and modest gains in reliability, suggesting enhanced behavioral engagement. Implications for survey design and data quality in psychological and educational research are discussed.