Barbaranelli, ClaudioLee, Christopher SVellone, ErcoleRiegel, Barbara2023-05-232023-05-232015-03-012018-08-06https://repository.upenn.edu/handle/20.500.14332/41591Knowledge of a scale's dimensionality is an essential preliminary step to the application of any measure of reliability derived from classical test theory--an approach commonly used is nursing research. The focus of this article is on the applied aspects of reliability and dimensionality testing. Throughout the article, the Self-Care of Heart Failure Index is used to exemplify real-world data challenges of quantifying reliability and to provide insight into how to overcome such challenges.This is a non-final version of an article published in final form in Barbaranelli, C. et al. (2015). The Problem with Cronbach's Alpha: Comment on Sijtsma and van der Ark (2015). Nursing Research 64, no. 2: 140-145. doi: 10.1097/NNR.0000000000000079HumansModels, StatisticalNursing ResearchReproducibility of ResultsHumansModelsStatisticalNursing ResearchReproducibility of ResultsAnalytical, Diagnostic and Therapeutic Techniques and EquipmentCardiologyCardiovascular DiseasesCirculatory and Respiratory PhysiologyHealth and Medical AdministrationHealth Services AdministrationHealth Services ResearchMedical HumanitiesMedicine and Health SciencesNursingPreventive MedicineArticle