In this paper, we evaluate the factorial validity of the Spanish short version of the Utrecht Work Engagement Scale (UWES-9) and assess its predictive validity with respect to self-assessed work performance. A total of 229 employees from educational institutions in Ecuador participated. Using a model comparison analysis, the unidimensional model exhibited an excellent goodness of fit, χ2 = 26.176 (24), p = .344; CFI =1.000; TLI = 1.000; RMSEA = .020; SRMR = .034; it was not improved by more complex models, Three-factor model: χ2 = 22.148 (21), p = .391; CFI =1.000; TLI = 1.000; RMSEA = .016; SRMR = .033. Two-factor model: χ2 = 26.080 (23), p = .297; CFI = 1.000; TLI = 1.000; RMSEA = .025; SRMR = .034). Therefore, it is justified as a unidimensional instrument of work engagement. However, upon analyzing the correlation patterns of the overall score and the work engagement dimensions in relation to the task performance, contextual performance, and counterproductive behaviors, we conclude that, while the unidimensional model exhibits a good fit, the three-factor theoretical approach is substantively superior in that it maintains differential predictive validity for each theoretical dimension.
Keywords: UWES–9; Utrecht Work Engagement Scale; construct validity; work engagement.