Including vulnerable groups of students such as students with learning disabilities in mainstream school research, require ethical considerations and questionnaire adaptation. These students are often excluded, due to low understanding or methodologies generating inadequate data. Students with disability need be studied as a separate group and provided accessible questionnaires. This pilot study aims at developing and evaluating student self-reported measures, rating aspects of student experiences of school-based Physical Education (PE). Instrument design, reliability and validity were examined in Swedish secondary school students (n = 47) including students, aged 13, with intellectual disability (n = 5) and without impairment and test–retested on 28 of these students. Psychometric results from the small pilot-study sample were confirmed in analyses based on replies from the first wave of data collection in the main study (n = 450). Results show adequate internal consistency, factor structure and relations between measures. In conclusion, reliability and validity were satisfactory in scales to measure self-efficacy in general, in PE, and aptitude to participate. Adapting proxy ratings for functioning into self-reports indicated problems. Adequacy of adjustments made were confirmed and a dichotomous scale for typical/atypical function is suggested for further analyses.