Marmara Sibling Jeaolusy Scale Short Form: Validity and Reliability Study

This study aims to perform the validity and reliability studies for a short form based on the 31-item marmara sibling jealousy scale developed by kurt (2017) for measuring middle-school students’ jealousy levels toward their siblings (the original scale measures mothers’ perceptions of jealousy among their children). the study group of the research is comprised of 860 middle schools for the exploratory factor analysis and 700 students selected from middle schools in pendik, istanbul in the 2015-2016 and 2017-2018 academic years for the confirmatory factor analysis. as a result of the multistep exploratory factor analysis, the validity studies have determined the scale to have 31 items and four factors that explain 65.14% of the total variance with eigenvalues greater than 1. however, the scale has been evaluated as having a single factor, because the difference the first factor has with the other factors is very large (46.77%). ten more items were eliminated in the evaluation stage. thus, the final version of the scale has been reached with 21 items. in the second study group (n = 700), confirmatory factor analysis of the test-retest has determined the goodness-of-fit values (x^2/df = 1.58; p < .001) for model 2 to show good fit and the other indicators of fit to have appropriate ranges (rmsea between .03 and .08; rmr between .05 and .15; and nfi between .69 and .8. the reliability study shows cronbach’s alpha to have a value of α = .96; test-retest correlations of r = .80; and split-half reliability r1-2 = .81. the results reveal the marmara sibling jealousy scale short form to have sufficient reliability and validity levels.