Open World Assumption
The Open World Assumption (OWA) is the assumption that that what is not known to be true or false might be true, or absence of information is interpreted as unknown information, not as negative information. It assumes incomplete information about a given state of affairs, i.e., there may be more relevant information than what is provided. This is useful for describing knowledge in a way that is extensible and most commonly used in Artificial Intelligence and throughout the life sciences. This is contrasted with the Closed World Assumption.