High Quality Content by WIKIPEDIA articles! Descriptive knowledge, also declarative knowledge or propositional knowledge, is the species of knowledge that is, by its very nature, expressed in declarative sentences or indicative propositions. This distinguishes descriptive knowledge from what is commonly known as "know-how", or procedural knowledge (the knowledge of how, and especially how best, to perform some task), and "knowing of", or knowledge by acquaintance (the knowledge of something`s existence).