The following is a report I wrote for my Artificial Intelligence course in November 2006. It discusses Franklin Chang's article entitled "Symbolically speaking: A connectionist model of sentence production."
F. Chang developed neural networks to produce proper sentences from basic messages. His networks were implemented on LENS neural network software. This research was performed around the year 2000 and a paper detailing his research and findings was published as an article in Cognitive Science in 2002. In this paper, I will explain, summarize, and analyze his article.
Background
Because Chang's models are neural networks mimicking human linguistic abilities, comprehension of his work relies on familiarity with linguistics and connectionist models. Linguistics will be addressed as necessary throughout this paper. A neural network is a computing model comprised of nodes (also called units) grouped into layers. The nodes between two layers are connected by weights. As nodes are activated, the activations of each layer are passed forward to the next layer by the connecting weights. Layers are connected in a forward-feeding fashion so that there are no loops. The value of a weight determines how much of the activation from the sending node is transferred to the receiving node. The total of all the activations received by a node determines its activation value. The result is a network of nodes that pass activations forward through the network. Activations originate from the input layers, which serve as the input for the network. These activations feed-forward to the output layers, whose activations serve as the output of the network. Learning occurs as weights are adjusted to correct the actual output values to match the desired output values.