An Online Large-group One-session Treatment for Public Speaking Anxiety

Comprising both groups, the investigators expect a reduction in public speaking anxiety. This effect should be present comparing pre-treatment anxiety to the anxiety reported at the assessment points directly after treatment, one month after treatment and six months after treatment. The change in reported anxiety between the two assessment time points before treatment is used as a control condition as there is no waitlist control group that is assessed but not treated. The reduction in public speaking anxiety is expected to be larger when comparing the assessments before and after treatment than in the control period before treatment. Furthermore, the investigators hypothesize participants to benefit from the intervention in terms of other constructs, namely socially phobic cognitions and fear of negative evaluation. Besides the hypotheses regarding general efficacy of the intervention, the investigators expect the reduction in public speaking anxiety in the EV group to be larger than in the BASIC group. This superiority of the EV condition should be present at the assessment points directly after treatment, one month after treatment and six months after treatment. The sample under investigation will be a sample of anxious individuals recruited from the community. All participants can attain the intervention for free and there is no payment for participation. On a website created for the project, interested parties can receive information on the project and can self-screen their public speaking anxiety and generalized social anxiety. Participation is recommended if public speaking anxiety is high and if general social phobia is low. After registration for the study, participants are asked to fill out a survey through a link sent to them via e-mail. This survey comprises all outcome measures. The same procedure is carried out two days before, one day after, one month after and six months after treatment. The target sample size is 100 participants. The decision for that number is not based on power calculations as there was no study before that conducted an online large-group one-session intervention for the treatment of public speaking anxiety and therefore effect size estimates would be random. Instead, the target sample size can be ascribed to organizational purposes. In terms of the general efficacy hypothesis, the primary outcome measure will be analyzed with a repeated measures ANOVA covering the assessment time points after registration, two days before and one month after treatment. For all other outcome measures, the investigators will use a rmANOVA comprising all five assessment time points, i.e. after registration, two days before the intervention, one day after the intervention, one month after the intervention and six months after the intervention. Furthermore, there will be paired comparisons between the public speaking anxiety scores at each of the assessment time points. These analyses will be conducted not only for public speaking anxiety but also for social phobic cognitions, fear of negative evaluation and other psychological constructs such as positive mental health. Regarding the expectancy violation hypothesis, the primary outcome measure will be analyzed with a 2x3 repeated measures ANOVA. For all other outcome measures, the investigators will use 2x5 between-within repeated measures ANOVAs (rmANOVA) to analyze the results. The first factor is a between-subjects factor that comprises the two groups BASIC and EV. The second factor is a within-subjects factor reflecting the five assessment time points after registration for the study, two days before the intervention, one day after the intervention, one month after the intervention and six months after the intervention. This analysis will be conducted for public speaking anxiety, social phobic cognitions and fear of negative evaluation. Moreover, there will be paired comparisons between the two groups for each of the assessment time points.