A DEVELOPMENT OF GOODNESS SCALE BY USING ANCHORING VIGNETTES FOR SCORE ADJUSTMENT การพัฒนามาตรวัดคุณค่าความดีโดยใช้แองเคอร์ริง วินเยตต์ ปรับแก้ค่าคะแนน

Abstract

Anchoring vignettes is an instrument that can be used to reduce the problem of validate individual scores in different self-assessment. The purpose of this research was to develop and test psychometric properties of Goodness Scale using anchoring vignettes for score adjustment. Research were students in Grade 9 from schools in Bangkok, 57 students by simple random sampling for analyze the sequence of vignettes items and reliability and 250 students by stratified random sampling for analyze confirmatory factor analysis. Instrument was goodness scale. For the data analysis, reliability were analyzed by using SPSS, Confirmatory factor models were validated by LISREL, whereas the anchoring vignettes’ order validation were done by using R. Findings were as follows; 1) content validity of goodness scale in sets of anchoring vignettes ranged between 0.71 to 1.00 and sets of rating scale items ranged between 0.57 to 1.00, 2) score adjustment of goodness scale with R showed decimal which the position of the response compared to the other respondents, 3) there was no reversal sequence of goodness scale in sets of anchoring vignettes, and 4) goodness scale in sets of rating scale items had reliability after score adjustment of whole scale was 0.914 and for its subscale ranged between 0.717 to 0.878. Construct validity analyzed by confirmatory factor analysis revealed that the model of Goodness was fitted to the empirical data (Chi-square = 1.78, df = 2, p = 0.411, GFI = 0.997, AGFI = 0.979, RMR = 0.03, RMSEA = 0.000).