the difficulty of interpreting unrotated principal components, and the mathematical trade-offs that happen when you try to fix it by rotating the axes

measure the strength and direction of the relationship between each original variable and a principal component

a statistical method used to reduce a large number of observed variables into a smaller, unobserved set of underlying dimensions called latent factors

a category, variable, or theoretical construct represents a single, uniform set of properties or meanings rather than a mix of diverse or overlapping phenomena