بررسی روایی و پایایی نسخه فارسی پرسشنامه ارزیابی ویژگیهای شناختی علائم تصویری با کاربری علائم ترافیکی

Background and aims: The Symbolic signs are important tools, designed to convey a message and can transmit a lot of information to the viewer at a glance. Understanding of symptoms is very important especially when they transmit safety information. Signs and symbols have characteristics which affect understanding of them. McDougall et all) 1996(introduced the five key cognitive features of symbolic signs including: concreteness, complexity, meaningfulness, familiarity and semantic distance. This study aimed to assess the validity and reliability of the Persian version of McDougall questionnaire for assessing cognitive features of traffic signs. Methods: The original questionnaire was translated from English to Persian by method of Backward-Forward. 8 experts helped to determine the face validity of the questionnaire .For Content Validity Ratio and Content Validity Index, Lavshy and waltz-Basel methods were considered and also Scale-level Content Validity Index was determined. The questionnaire was designed for 25 signs and 80 subjects participated in this study. The participants subjectively rated five features of each sign from 0 to 100. The reliability and internal consistency of questionnaire were defined by Cronbach's alpha coefficient. Finally, using test–retest and intra-cluster correlation index, stability of questionnaire was reached. Results: All questions of cognitive characteristics questionnaire had score higher than the acceptable content validity ratio and completely accepted. Content validity index of questionnaire for all the questions were above 0.79 or acceptable score. Scale-level Content Validity Index was 0.928. Inter-cluster correlation index was 0.995 and Cronbach's alpha coefficient was equal to 0.922. Conclusion: This study showed that the Persian version of cognitive sign features is a reliable tool for evaluating of cognitive features which has high reliability and validity and can be used in the evaluation of cognitive features of traffic signs and the other symbolic signs.