Slider bars in multi-device web surveys

This study explores some features of slider bars in the context of a multi-device web survey. Using data collected among the students of the University of Trento in 2015 and 2016 by means of two web surveys (N = 6,343 and 4,124) including two experiments, we investigated the effect of the initial position of the handle and the presence of numeric labels on answers provided using slider bars. It emerged that the initial position of the handle affected answers and that the number of rounded scores increased with numeric feedback. Smartphone respondents appeared more sensitive to the initial position of the handle but also less affected by the presence of numeric labels resulting in a lower tendency to rounding. Yet, outcomes on anchoring were inconclusive. Overall, no relevant differences have been detected between tablet and PC respondents. Understanding to what extent interactive and engaging tools such as slider bars can be successfully employed in multi-device surveys without affecting data quality is a key challenge for those who want to exploit the potential of web-based and multi-device data collection without undermining the quality of measurement.