Determine the Psychometric Properties of Green et al. Paranoid Thoughts Scale (GPTS)

Document Type : Research Paper

Authors

1 Graduate of Personality Psychology, Department of Psychology, Karaj Branch, Islamic Azad University, Karaj, Iran.

2 Assistant Professor, Department of Psychology, Karaj Branch, Islamic Azad University, Karaj, Iran.

Abstract

The aim of the present respectively study was to investigate the validity and reliability of Paranoid Thought Scales in Iranian sample.
For estimating the psychometric properties of the scale, 491 university students in KARAJ were selected and scales executed for them.
To check the construct validity of EFA with principal components and CFA were used. Sampling adequacy (KMO=0.897) and Bartlett's test of sphericity indicate favorable conditions for factor analysis was performed. Based on these findings, GPTS is saturated two factors of the total 41.46% of the total variance. Also significant fitness indices in confirmatory factor analysis of the two-factor model derived from the exploratory factor analysis was confirmed. Also a significant correlation between scale scores and subscale scores of the paranoid thought and paranoid scale’s scores in MCMI represents the criterion validity of the scale. Analysis of the data indicated that the internal consistency of the scale based on Cronbach's alpha coefficient of 0.908 and the split-half of the 0.912. Test-retest stability coefficient for the total scale and its subscales were statistically significant.
This questionnaire is reliable and valid scale to measure Iranian sample’s paranoid thought.

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Main Subjects


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