Background and Purpose: This study aimed to investigate the validity of picture symbols included in a questionnaire developed for the survey of needs and satisfaction at the G Lifelong Education Center for People with Disabilities in 2021, considering the characteristics of disabilities. Methods: A survey on the iconicity and comprehensibility of picture symbols included in the questionnaire was conducted on 38 adults with developmental disabilities, 32 adults with language-hearing impairments, and 27 professionals working in related institutions. Two experts were consulted to assess the suitability of the questionnaire based on the Easy-to-read guidelines. Results: For individuals with developmental disabilities, overall accuracy in tasks related to iconicity was low, while comprehension of symbolic representation was high. In contrast, individuals with language-hearing impairments generally showed low comprehension of symbols, and symbols that exhibited low average accuracy in iconicity testing also showed low average scores in comprehension tests. The analysis of symbol comprehension in professionals working in related institutions was similar to that of individuals with language-hearing impairments but differed from those with developmental disabilities. Conclusion: The results of this study indicate differences in the ability to infer the meaning of symbols included in the questionnaire based on the type of disability. Furthermore, it was anticipated that by incorporating feedback from experts based on Easy-to-read guidelines to modify and improve the questionnaire, a more tailored questionnaire for different types of disabilities could be developed to better serve its intended purpose.