Validation of The Purpose in Life Scale-Short Form in an Ecuadorian sample: factor analysis, reliability and graded response model

Introduction: The purpose in life is analyzed within psychological well-being, it deals with the meaning of life that people have, which has implications in areas such as mental health. Currently, precise instrumentation is required for its assessment of the Ecuadorian population, which at the moment is limited. Objective: To corroborate the unidimensional structure of the Purpose in Life Scale-Short version (PIL-SF), the equivalence of measurement according to gender, the reliability and the parameters of discrimination and difficulty in a sample of Ecuadorian adults. Methods: Instrumental study of the PIL-SF under the precepts of Classical Test Theory and Item Response Theory. Participants: 743 Ecuadorian adults (64.2% women and 45.8% men) aged 18 to 73 years (M = 24.7, SD = 7.9). Results: The unifactorial structure of the PIL-SF with adequate adjustment was confirmed. In addition, the PIL-SF is invariant at the strong level based on gender and no differences are presented at the level of latent means. The internal consistency reliability is acceptable per group and the discrimination and item difficulty parameters are adequate. Conclusion: The PIL-SF is a valid, reliable, and accurate tool to measure the Purpose in Life construct in Ecuadorian adults.