Here is the design of a clinical trial:

Official Title: Developing and Evaluating a Social Skills Group Training for Adolescents on the Autism Spectrum

Included conditions:
- Autism Spectrum Disorder

Study Armgroups:
- {'label': 'KONTAKT Australia', 'type': 'EXPERIMENTAL', 'description': 'A social skills group training', 'interventionNames': ['Behavioral: KONTAKT Australia']}
- {'label': 'Super Chef', 'type': 'ACTIVE_COMPARATOR', 'description': 'A social cooking group', 'interventionNames': ['Other: Super Chef']}

Interventions:
- {'type': 'BEHAVIORAL', 'name': 'KONTAKT Australia', 'description': 'KONTAKT is a manualized Social skills group training program designed for children and adolescents on the Autism Spectrum aimed at improving communication, social interaction skills, the severity of ASD symptoms, and the ability to empathise and adapt in a group setting. The KONTAKT participants (4-8 participants) meet face to face weekly for 16 weeks for an hour and a half in a group facilitated by two trainers.', 'armGroupLabels': ['KONTAKT Australia'], 'otherNames': ['KONTAKT']}
- {'type': 'OTHER', 'name': 'Super Chef', 'description': 'The Super Chef is a cooking group designed for this study for adolescents on the Autism Spectrum, aimed at teaching basic cooking skills in a social environment. The Super Chef participants (4-8 participants) meet face to face weekly for 16 weeks for an hour and a half in a group facilitated by two trainers.', 'armGroupLabels': ['Super Chef'], 'otherNames': ['Social cooking group']}

Primary Outcomes:
- {'measure': 'Change in the Goal Attainment Scale (GAS)', 'description': "The GOAL Attainment Scale will be used as the adolescents' primary outcome. Using the scale the participants personally meaningful social goals will be specified, and a behavioural expectation that ranges from the worst to the best possible outcome will be listed for each goal. This allows qualitative data to be quantified in relation to the success of the participant in achieving expectations of change.", 'timeFrame': 'Baseline (week 0), Post-test (week 20), follow up (week 36), and long follow up (week 74)'}

Please estimate the sample size based on the assumption: 
Power of 0.95, significance level (α) of 5%, and an attrition rate of 37%.
Sample size calculations
        The KONTAKTÂ© study in Sweden (both 12-week and 24-week versions) employed the Social Responsive Scale - second edition (SRS-2) as the primary outcome measure. Based on an effect size of 0.54, derived from roughly averaging the effect size (ES) as measured by the SRS-2 from trials examining the efficacy of the long 24-session (ES = 0.76) and the short 12-session (ES = 0.32) versions of KONTAKTÂ© at post-test, and applying multivariate analysis of variance (MANOVA) for repeated measures (within-between interactions) at the three time points (using the intent-to-treat approach), a minimum of 57 participants are required (as calculated by G*Power [53] with power of 0.95 at a conventional error probability (Î± = 5%)). However, unlike the Swedish study, the present study will employ the Goal Attainment Scaling (GAS) as the primary outcome. It has been argued that GAS has good reliability when used as an outcome measure with interventions for adolescents with ASD [54â56]. Further, unlike previous investigation of KONTAKTÂ© [17, 32], the current study will compare this SSGT efficacy against an active control group, to control for exposure to a social context with peers with ASD. It is likely that both these factors will have a limiting impact on the power of the study, and as such we will aim to recruit a sample of at least 90 participants into this study, increasing the likelihood of detecting possible effects [19]. This sample size will also account for an attrition rate of 37%, which is larger than what is expected based on the previous KONTAKTÂ© studies.