Effect Size of Testimonials on Treatment Choice in PTSD

4.8%, respectively, which indicate only a minor difference from zero. For those participants who have received prior psychoor pharmaco-therapy, the average effect size was even lower, at 3.3 and 1.9%. Overall, the effect of the testimonials for both groups combined was 5.3%, which is neither clinically significant nor statistically significant (p = 0.179). Therefore, the conclusion from the study that positive video testimonials on available PTSD treatments affect the opinion of treatment naïve individuals is not supported by the data in this study. Second, there were 40 statistical tests in the results section of the above study related to testimonials. Two out of the 40 would be expected to be significant by chance alone due to Type II error. That is, no correction was made for the number of tests conducted. After applying the Bonferroni correction to the data in the study, the alpha level was 0.00125 and none of the testimonial related findings were statistically significant. This indicates that the responses from the video testimonials were likely from chance associations, not meaningful responses to the study. Therefore, the conclusion that the video testimonials positively affect views on treatment is contradicted by the lack of statistical significance for any of the tested groups in the study. Effect size of testimonials on treatment choice in PTSD