Writing about style in architecture, the nineteenth-century theorist Viollet-le-Duc asserted that "style consists in distinction of form," and complained that animals expressed this better than the human species. He felt that his contemporaries had "become strangers to those elemental and simple ideas of truth which lead architects to give style to their designs," and he found it "necessary to define the constituent elements of style, and, in doing so, to carefully avoid those equivocations, those high-sounding but senseless phrases, which have been repeated with all that profound respect which most people profess for that which they do not understand."
During the sixteenth and seventeenth centuries architects not only paid attention to internal arrangements, but subordinated the designs for the exterior to them. The usages of life dictated the arrangement and the arrangement suggested the form of the building. This was the dominant principle in times of Classical Antiquity and the Middle Ages.
Perceptual: "They couldn't figure out what to do next", "they couldn't find the feature", "they didn't know they could click that button..." etc.
Domain-specific: "We need a way to jump back here because in their workflow this happens..."
In general, usability testing only catches type 1 perceptual problems. Because in those tests you take people out of the real world and assign them tasks. Usability testing doesn't catch domain-specific problems because they only come up in real life use.