 The main example of network approaches is perhaps Collins and Quillian’s (1969) hierarchical network model, in which words are represented as entries in a network of nodes, each comprising a set of conceptual features defining the conventional meaning of the word in question, and connected to other nodes in the network through semantic relations (more in Lehman 1992). Subsequent developments of the hierarchical network model include the Semantic Feature Model (Smith, Shoben &amp; Rips 1974), the Spreading Activation Model (Collins &amp; Loftus 1975; Bock &amp; Levelt 1994), the WordNet database (Fellbaum 1998), as well as the connectionist models of Seidenberg &amp; McClelland (1989), Hinton &amp; Shallice (1991), and Plaut &amp; Shallice (1993). More on this in the entry on  connectionism.