Data is not information, information is not knowledge, knowledge is not understanding, understanding is not wisdom.

The line draws a deliberate hierarchy among ways of “having” something in the mind. Raw data are discrete measurements or symbols; information is data organized to answer basic questions; knowledge is information integrated into a person’s mental model and experience. Stoll then insists that even knowledge can fall short of understanding—grasping causes, relationships, and implications—and that understanding still differs from wisdom, which adds judgment about values, consequences, and what ought to be done. The quote is often invoked as a caution against technological or statistical overconfidence: accumulating more data does not automatically yield insight, and insight does not guarantee prudent action.