Unweaving the Definitions of Complexity

The definition of complexity is contentious. The lack of a univocal definition for complexity is leading to a cacophony of different views and lexicons, limiting the collective ability to handle complexity effectively. This article aims to resolve this impasse by identifying or developing a useful and acceptable definition of complexity by focusing on how this term is used in practice, and hence determine which definition resonates with the broadest possible community. To understand how the term is being used, several popular complexity-definitions have been identified and de-constructed into component definitional elements. These elements are then compared to the descriptions of complexity in a range of key community documents to infer which definitions most align with the document authors usage of the complex term. The results indicate that new emergent definitions are far more popular than the established dictionary and complexity theory definitions, supporting previous surveys. These usage insights are then analyzed to develop a definition that can unify, as much as possible, the different complexity perspectives. The proposed definition establishes that complex(ity) is when relationships between elements are weaved together such that they are not fully comprehended, leading to insufficient certainty between cause and effect. This definition was tested at a series of international workshops and accepted as the most useful definition.