Number of Hidden Nodes

Researchers have found that having a NN with too many nodes allows the network to memorize the patterns being presented, thus eliminating the need to extract dominant patterns and features from the training samples. Although this causes very good outputs when the training samples are presented during the testing phase, performance decreases (usually below acceptable levels) when novel patterns are shown to the network ( see, for example, Caudill (1990) ). At the same time, since it is the hidden nodes that act as memory, not having enough nodes can deprive the network of the ability to remember factors that might be important for the task at hand. Deciding how many hidden nodes for a problem like sentence parsing is still an open question.

Back to the Table of Content

Back to the previous subject

To the next subject