(1) Background: Adolescents spend a considerable amount of their time in the school environment. Most adolescents are also subjected to compulsory school attendance, implying that they have to deal with the environment on a daily basis. In health research adolescent perceptions about the school environment are often linked to mental and psychosomatic health. However, measurements seems to be focused on psychosocial or psychological aspects of the school environment more often than physical.
(2) Aims: The purpose of the present study is to examine the psychometric properties of a scale of Adolescent Perceptions of the Physical School Environment by means of the Rasch model for ordered response categories.
(3) Sample: The analysis is based on the survey Young in Värmland which is a paper-and-pencil based survey, conducted recurrently since 1988 targeting all adolescent in school year 9 residing the county of Värmland, Sweden. So far, more than 20,000 individuals have participated in the survey. In the analysis presented here, five items based on adolescents’ perceptions of the physical school environment were subjected to analysis using RUMM2030, in total about 22,000 individuals.
(4) Methods: A scale consisting of five polytomous items is analysed by means of the polytomous Rasch model. General fit statistics as well as their graphical representations (ICC) are used to evaluate if the scale fit the Rasch model. A particular focus is also directed towards possible Differential Item Functioning (DIF) across sex.
(5) Results: At a general level of analysis the scale subjected to analysis seems to fit the Rasch model fairly well, with good separation of the individuals, and showing no reversed item thresholds, i.e. the response categories work properly and as expected. Also, at a finer level of analysis focusing on DIF, the scale works fairly well, but with exceptions important in order to understand differences between boys and girls.
(6) Conclusions: Although the scale fits the Rasch model fairly well, there is room for improvements. In particular the precision of measurement may be increased by improving the targeting through inclusion of additional items of appropriate severity.
Pacific-Rim Objective Measurement Symposium (PROMS 2014) 4-6 Aug Guangzhou, China