Knowledge can be defined as the condition of knowing based on experience. But that simple definition masks a long-running philosophical debate about the nature of knowledge. Epistemology is a branch of philosophy that concerns itself with the nature of knowledge. It explores what it means to really know something and questions if knowledge is even possible. Philosophers have a long tradition of disagreeing about the definition of knowledge that dates back to the ancient greeks. The crux of the problem of defining knowledge is differentiating it from belief. Knowledge relates to facts or things that are deemed to be true. Some philosophers have argued that knowledge must be justified, making them reasonable judgments based on evidence. Skeptics have argued that knowledge is impossible because there is always a reason to doubt something is true. They ask whether it is possible to prove that we are not dreaming or living inside a computer simulation. For practical purposes, we’ll leave this debate to the philosophers and assume that it is possible to know things while recognizing that there is no absolute truth. What we consider knowledge one day may be proven wrong the next.
If we assume that there is such a thing as knowledge, which many pragmatically inclined people do, then it becomes clear that there are many different kinds of knowledge and that different fields use different terms to label them. In the context of learning a common classification of knowledge has the following types:
- Factual: Knowledge of valuable but isolated bits of information like facts and terminology
- Conceptual: More complex and organized knowledge such as categories, classifications, schemas, mental models, principles or theories.
- Procedural: Knowledge of how to do something, often by following a sequence of steps. Examples include skills, algorithms, techniques, and methods.
Metacognitive: knowledge about cognition in general and of one’s own thinking.