Originally answered Jun 15, 2017
Here are three useful definitions of knowledge.
1. Attributed to Peter F. Drucker:
The knowledge that we consider knowledge proves itself in action. What we now mean by knowledge is information in action, information focused on results.
2. Bruce Karney:
Knowledge is the mental capacity for effective performance. Knowledge as defined here can be ascertained by paper-and-pencil testing. The pure unit of measure of knowledge is accurate answers, but in many situations we judge knowledge based on both speed and accuracy.
The emphasis in all these cases is on knowledge being “actionable” because of the business context, and on knowledge being a refinement of information because that’s how we extracted value from data. That may be a useful way of thinking about the value of information, but it’s pretty far from what knowledge has been during its 2,500 year history. Throughout that period, Plato’s definition has basically held: Knowledge is the set of beliefs that are true and that we are justified in believing. Indeed, we’ve thought that knowledge is not a mere agglomeration of true beliefs but that it reflects the systematic and even organic nature of the universe. The pieces go together and make something true and beautiful. More, knowledge has been the distinctly human project, the exercise of the highest and defining capabilities of humans, a fulfillment of our nature, a transgenerational treasure that it is each person’s duty and honor to enhance.