Unidimensional item response theory (IRT) models are useful when each item is designed to measure some facet of a unified latent trait. In practical applications. items are not necessarily measuring the same underlying trait. and hence the more general multi-unidimensional model should be considered. https://www.bekindtopets.com/limited-deal-Neutral-Checkered-Galaxy-Note-10-Pro-Case-p51042-best-super/