The jittered density plots of hidden units may contain areas which are distinctly separated from other areas in the output range. These areas are called bands, and can be used in interpreting the pattern classification functionality of the hidden unit [Berkeley95] (see Section 4.2.3). The jittered density plot seen in Figure 5 apparently contains roughly 5 bands.
This type of analysis is done by manually choosing the bands from the density plots. Each band will contain certain inputs that result in activations that fall into the band. The tool used for analysis is Jitter.m (described in Section 4.2.2) of which a snapshot is seen in Figure 5.
Separators are used for limiting bands. The range of the plot displayed can be partitioned by placing separators at the desired boundary positions. A separator can be moved by clicking with the mouse button and dragging accross the display. When clicking the mouse on the display will highlight the nearest separator. Also, whenever a separator is manipulated it will be highlighted to become the current one.
The three buttons on the top of the window help select bands from the plot and then start analysis. The functionality of the buttons is described as follows: