DIFSIB: A SIBTEST Package

The R package DIFSIB provides a direct translated version of the SIBTEST, Crossing- SIBTEST, and POLYSIBTEST procedures that were last updated and released in 2005. Having these functions directly written from Fortran into R code will allow researchers and practitioners to easily access the most recent versions of these procedures when they are conducting differential item functioning analysis and continue to improve the software more easily.

Development of the Paranormal and Supernatural Beliefs Scale using classical and modern test theory

Background This study describes the construction and validation of a new scale for measuring belief in paranormal phenomena. The work aims to address psychometric and conceptual shortcomings associated with existing measures of paranormal belief. The study also compares the use of classic test theory and modern test theory as methods for scale development. Method We combined novel items and amended items taken from existing scales, to produce an initial corpus of 29 items. Two hundred and thirty-one adult participants rated their level of agreement with each item using a seven-point Likert scale. Results Classical test theory methods (including exploratory factor analysis and principal components analysis) reduced the scale to 14 items and one overarching factor: Supernatural Beliefs. The factor demonstrated high internal reliability, with an excellent test–retest reliability for the total scale. Modern test theory methods (Rasch analysis using a rating scale model) reduced the scale to 13 items with a four-point response format. The Rasch scale was found to be most effective at differentiating between individuals with moderate-high levels of paranormal beliefs, and differential item functioning analysis indicated that the Rasch scale represents a valid measure of belief in paranormal phenomena. Conclusions The scale developed using modern test theory is identified as the final scale as this model allowed for in-depth analyses and refinement of the scale that was not possible using classical test theory. Results support the psychometric reliability of this new scale for assessing belief in paranormal phenomena, particularly when differentiating between individuals with higher levels of belief.

Validation of the Revised Olweus Bully/Victim Questionnaire (OBVQ-R) Among Adolescents in Chile

Bullying is a phenomenon that affects children and adolescents worldwide, and it has major consequences for all participants involved in these situations. In Chile, researchers have validated several instruments used to investigate aggression between peers and school violence, but there is a lack of validation of instruments to investigate bullying. The purpose of this study was to provide evidence of the validity and reliability of the Olweus Bully/Victim Questionnaire—Revised version (OBVQ-R) in the Chilean context. The participants were 2,775 students from schools of low, medium, and high socioeconomic status. OBVQ-R is a self-report questionnaire with 42 items, which has been used in different countries, and has adequate psychometric properties to assess the prevalence of victimization and aggression and various forms of bullying worldwide. Results confirmed the two-factor structure of the OBVQ-R (victimization and perpetration subscales) and good reliability (ω = 0.81 and ω = 0.75, respectively). These dimensions seem to be correlated. Comparison between OBVQ-R with the School Violence between Peers Questionnaire and the Internet Experiences Questionnaire showed some degree of agreement. The Item Response Theory analysis showed that the item about verbal bullying, in both subscales, had the lowest-severity parameters, meaning that these forms of bullying were the most prevalent. The higher-severity parameter in the victimization scale was the cyberbullying item, and the sexual bullying item showed higher severity in the perpetration subscale. The differential item functioning analysis by gender showed a trend in which boys responded with lower-severity parameters than girls. In the victimization scale, the exception was the item about spreading rumors, and in the perpetration subscale, it was the item about racial bullying. We have provided evidence of the validation of OBVQ-R among school-age children and adolescents in Chile. This study is part of a trial registered at ClinicalTrials.gov, number NCT02898324.