Kuhlmann, T., Reips, U.-D., Wienert, J., & Lippke, S. (2014, November). Using Visual Analogue Scales to increase response rates and compliance: Results from an eHealth intervention study. Präsentation auf dem 44th Annual Meeting der Society for Computers in Psychology, Long Beach, CA, US.

Visual Analogue Scales (VAS) have been shown to be a valid measurement instrument and better alternative to Likert-type scales in online research, both empirically and theoretically (Reips & Funke, 2008; Funke & Reips, 2012). Upsides include more differentiated responses, better measurement level and less error. The present study examined VAS in the context of an online lifestyle intervention for patients in cardiac rehabilitation and others interested in lifestyle change. A sample of 637 German participants with a mean age of 52.1 years (SD = 12.5) took part in the study. The intervention aimed at supporting participants over eight weeks with additional follow-up measurements. The participants were randomly assigned to either a Likert-type or VAS version of the measures, which differed only in the answer scale formats presented. Results showed that neither means nor standard deviations of items or scales differed across the versions. However, participants in the VAS condition produced fewer missing values, on average about 10% less. Furthermore, the VAS condition exhibited significantly less dropout during the eight-week intervention period. As a consequence, the VAS may lead to better health effects in the long run and improved maintenance of lifestyle changes. These results provide further support for the use of VAS in online research, extending the scope to senior samples in the health context. As this is an ongoing intervention, we will be able to report further results during the conference.