Databases Reference
In-Depth Information
Figure 5.5
Option Panel
As you move to the left, you see the surface plot move upwards,
indicating that as SepalLength decreases, the likelihood of the Setosa variety
increases.
Drag the SepalLength slider to the right.
As you drag, the likelihood drops - iris flowers with long sepals are very
unlikely to be of the Setosa variety.
Drag the SepalLength slider back to 6.1.
Drag the SepalWidth slider to the left and to the right.
The contribution of SepalWidth to the likelihood of being Setosa is opposite
that of SepalLength. That is, as SepalWidth increases the likelihood of being
Setosa increases.
In addition to the up and down movement of the plot surface, as you changed
the values of SepalLength and SepalWidth, did you notice a change in shape of
the plot surface? When you see a change in shape, it is indicative of
interaction
between the axis attributes and the attribute being changed. Interaction means
that the nature of the contribution of one attribute changes depending on the
level of a second attribute. That is, it does not make the same contribution
independent of the other input values. When you see the plot surface rise or fall
without a dramatic change in shape, the contributions of each are said to be
independent
.
