A model of knowledge representation and information processing according to which items of knowledge are represented by patterns of connections of varying strengths between locations within a network model, information processing taking the form of parallel processing of collections of activated connections. The term is almost synonymous with connectionism (1). See also back-propagation algorithm, cascade processing, content-addressable memory, delta rule, distributed network model, gradient descent, Hebbian rule, hill climbing, neural network, teacher unit. Compare distributed cognition. PDP abbrev.