Reliability Generalization as a Seal of Quality of Substantive Meta-Analyses: The Case of the VIA Inventory of Strengths (VIA-IS) and Their Relationships to Life Satisfaction

Reliable test scores are essential to interpret the results obtained in statistical analyses correctly. In this study, we used the Values in Action Inventory of Strengths (VIA-IS) as an example of a widely applied assessment instrument to analyze its metric quality in what is known as reliability generalization (RG). In addition, we conducted a meta-analysis of the correlations between character strengths and life satisfaction to examine the potential relationship between the reliability of test scores and the intensity of these correlations. The overall variability of alpha coefficients supports the argument that reliability is sample dependent. Indeed, there were statistically significant mean reliability differences for scores across the 24 scales, with the highest level of reliability observed for Creativity and the lowest for scores on Self-regulation. Significant moderators such as the standard deviation of the scores and the sample type contribute to understand the high variability observed in the reliability estimation. The second meta-analysis showed that Zest, Hope, Gratitude, Curiosity, and Love were the character strengths that were highly related to life satisfaction, while Modesty and Prudence were less related to life satisfaction. Furthermore, the high heterogeneity between samples might be an indicator of the relationship between the variability of reliability of character strengths' scores and the intensity of their correlations with life satisfaction. Those character strengths with high-potential RG are related or unrelated to life satisfaction, whereas character strengths with less-potential RG showed unstable correlation patterns. The results of both studies point out the role of the relationship between the reliability of test scores and substantive studies, such as Pearson's correlations meta-analysis.