Does the use of mobile devices (tablets and smartphones) affect survey quality and choice behaviour in web surveys?

Web surveys are becoming increasingly popular in survey research including stated preference surveys. Compared with face-to-face, telephone and mail surveys, web surveys may contain a different and new source of measurement error and bias: the type of device that respondents use to answer the survey questions. This is the first study that tests whether the use of mobile devices, tablets or smartphones, affects survey characteristics and stated preferences in a web-based choice experiment. The web survey on expanding renewable energy production in Germany was carried out with 3182 respondents, of which 12% used a mobile device. Propensity score matching is used to account for selection bias in the use of mobile devices for survey completion. We find that mobile device users spent more time than desktop/laptop users to answer the survey. Yet, desktop/laptop users and mobile device users do not differ in acquiescence tendency as an indicator of extreme response patterns. For mobile device users only, we find a negative correlation between screen size and interview length and a positive correlation between screen size and acquiescence tendency. In the choice experiment data, we do not find significant differences in the tendency to choose the status quo option and scale between both subsamples. However, some of the estimates of implicit prices differ, albeit not in a unidirectional fashion. Model results for mobile device users indicate a U-shaped relationship between error variance and screen size. Together, the results suggest that using mobile devices is not detrimental to survey quality.

A sorrow shared is a sorrow halved? Internet-based group therapy versus individual therapy for social anxiety disorder: A randomized controlled trial

Purpose: Social anxiety disorder is one of the most researched conditions in the field of Internet-based self-help. Various studies have shown that cognitive-behavioral treatments can be efficacious to reduce social phobic symptoms. Most of the interventions tested include some form of support, whereas the efficacy of a web-based group format has yet to be investigated. The present study aims at investigating the possible added value of therapist-guided group support in an Internet-based guided self-help treatment for SAD. Methods: A total of 150 adults with a diagnosis of SAD are randomly assigned to either a wait-list control group or one of two active treatment conditions. Participants in the two active conditions use the same Internet-based self-help program, either with individual guidance by a therapist or with the support of a therapist-guided group of 6 individuals. In the group condition, participants communicate with each other via an integrated, protected discussion forum. The primary outcome variables are symptoms of SAD and diagnostic status immediately after the intervention (12 weeks) and at 6-month follow-up. Secondary endpoints are general symptomatology, depression, quality of life and adherence to treatment. Furthermore, process variables such as group processes and the working alliance are studied. Results: Results are currently being analyzed. Results at post-treatment will be presented and discussed. Potential moderating and mediating variables of treatment success will be addressed. Conclusion: The results of this study should indicate whether therapist-guided group support could enhance the efficacy of an internet based self-help treatment for SAD. This novel treatment format, if shown efficacious, could represent a cost-effective option and could be further modified to treat other conditions.