CONFIRMATORY VALIDATION OF AN INTERNATIONAL SCALE ( I -PANAS - SF ) AMONG UNIVERSITY UNDERGRADUATES USING ITEM RESPONSE THEORY

Abstract

 The study confirmed the factor structure of affect scale among undergraduate students of ObafemiAwolowo University, Ile-Ife and it determined the model fit of each of the positive and negative affect among the undergraduates. The study also ascertains the average scale and item discriminating power of the scale among ObafemiAwolowo University, Ile-Ife undergraduates and established the reliability of the affect scale in recent time among the University undergraduates. These were with the view of providing information on the psychometric properties and usability of the scale among university undergraduates. The study adopted the descriptive survey research design. The study population consisted of all the 29,514 male and female undergraduates of ObafemiAwolowo University, Ile-Ife for the 2018/2019 academic session. The sample comprised 1280 undergraduates that were selected using multistage sampling procedure. From the 13 faculties in the University, eight faculties were selected using simple random sampling technique and from each of the selected faculty a total of 160 undergraduates were selected using convenient sampling technique to make a total of 1280 undergraduates. An instrument titled “Positive and Negative Affect Schedule (PANAS-SF)” was adopted for collecting relevant data for the study. The scale is a self-report questionnaire that consists of two independent factors: positive and negative affect. Data collected were analysed using Model Fit Statistics {Root Mean Square Error of Approximation (RMSEA), Tucker-Lewis Fit Index (TLI) and Comparative Fit Index (CFI}, Item Response Parameter Model and Cronbach's Alpha Test. The results showed that the factor structure of the affect scale among ObafemiAwolowo University undergraduates was not consistent (RMSEA = 0.086, TLI = 0.697 CFI =0.746). The results also showed that while the positive affect fit the model and consistently measure the theoretical sub-construct (RMSEA = 0.039, TLI = 0.947 CFI =0.983) among the undergraduates, the negative affect did not fit the model and does not consistently measure the construct (RMSEA = 0.066, TLI = 0.808 CFI =0.424) among the undergraduates. The results further showed that on the average, positive and negative sub-factors of the scale moderately discriminates (x=0.997 and x= 0.823) respectively. In addition, the results showed that 90% of the items have high discrimination index. Finally, the results showed that the affect scale is reliable (r = 0.80). The study concluded that the Positive and Negative Affect Schedule (PANAS-SF) possessed good psychometric properties and usable among ObafemiAwolowo University undergraduates.It is also interesting to examine correlations between the PANAS scales and measures of related constructs, such as anxiety, depression, and general psychological distress. PANAS scales in conjunction with a number of other commonly used measures and report. This will help to gather information regarding the development of brief scales to measure the two primary dimensions of mood— Positive and Negative Affect. There is need for further studies to resolve the conceptual and empirical controversy