Deterministic Node

In a relevance diagram, a deterministic node or calculation node is a degenerate chance node representing a deterministic variable. The deterministic variable associated with a deterministic node can be viewed as an uncertain variable having a probability distribution, conditional on its direct predecessors, totally concentrated on a single outcome.

A deterministic node is drawn as a double bordered oval or circle. Typically, the deterministic node is internally represented by a table, function or spreadsheet. Recognising a node’s determinism can greatly simplify and speed its formulation and assessment. Relevance diagram evaluation algorithms can also be very efficient when they recognise deterministic nodes.

See also: asymmetric decision basis and coalescence.