Editing Influence diagram (section)

==Related concepts==

Influence diagrams are hierarchical and can be defined either in terms of their structure or in greater detail in terms of the functional and numerical relation between diagram elements.  An ID that is consistently defined at all levels&mdash;structure, function, and number&mdash;is a well-defined mathematical representation and is referred to as a ''well-formed influence diagram'' (WFID).  WFIDs can be evaluated using [[Node reversal|reversal]] and [[Node removal|removal]] operations to yield answers to a large class of probabilistic, inferential, and decision questions.  More recent techniques have been developed by [[artificial intelligence]] researchers concerning [[Bayesian inference|Bayesian network inference]] ([[belief propagation]]).

An influence diagram having only uncertainty nodes (i.e., a Bayesian network) is also called a '''relevance diagram'''.  An arc connecting node ''A'' to ''B'' implies not only that "''A'' is relevant to ''B''", but also that "''B'' is relevant to ''A''" (i.e., [[relevance]] is a [[symmetric]] relationship).