Adult Sensory Processing Scale (ASPS) Version of Turkish

The current study comprises three parts: cross-cultural adaptation, piloting, and examination of psychometric properties of the ASPS-T. The researcher contacted the developers of the original ASPS and received written permission from the authors to translate it into Turkish. This study was conducted by the Helsinki Declaration and Uskudar University. Clinical Research Ethical Board approved the study. After receiving both written and oral information about the project, all the study participants provided a signed consent form.

Phase 1: The cross-cultural adaptation process Translating the Turkish version of ASPS and the cross-cultural adaptation procedure was carried out under the guidance of Beaton et al. Translation from English to Turkish was performed by two therapists whose mother tongue is Turkish, also have fluent in English. Each of the translations was reviewed by three therapists, after the consensus on the final version, it was turned down by two native English-speaking translators. The final version was compared with the original version to reveal any inconsistencies; no discrepancies were observed. During the translation phase, minimal adjust were made to address linguistic.

Phase 2: Piloting process A pre-assessment was made with a pilot study to explore ASPS-Turkish's cultural harmony. The translated questionnaire was completed by 20 participants to identify any items that were not coherent. Four participants stated that they could not understand the meaning of avoid-kaçınmak, so investigators suggested yaşamamak, and this was accepted by participants. Three participants could not respond to the first item on factor 10, because participants had not traveled by boat or rides before, so that, investigators added the phrase "all types of vehicles" was added to the sentence. All the authors meet to compare the ASPS-T with the original version and assess its suitability after the minimal change, concluding that the current correction did not cause any loss of the meaning of the word. After the changes, pilot study participants evaluated the intelligibility of the scale with a 1 to 5 Likert scale, and confirm the clearness unanimously of them. Therefore, the final version of the ASPS-T which has minor changes was the best representation of the original, and each item was found to be suitable for Turkish patients. The pilot study participants were not included in the sample. After cultural equivalence had been achieved, 405 healthy individuals aged 18 and over were asked to complete the ASPS questionnaire.

Phase 3: Analysis of psychometric properties Exploratory and Confirmatory Factor Analysis (EFA and CFA) were used to measure the construct validity of the instrument, and test-retest analysis (interclass correlation coefficient) and Cronbach's alpha were used to evaluate the reliability of the instrument.

Inclusion criteria

• being aged 18-64 years, able to read and write, and being healthy

Exclusion criteria

• Who has a diagnosis of any disorders that preventing from completing the survey such as cancer or cognitive problems.