Interaction Graph

Graph of interactions between attributes

Signals

Inputs:

• Examples (ExampleTable)

  A table of examples

Outputs:

• Selected Examples

  ???

• Attribute Pair

  ???

• Selected Attributes

  ???

The widget computes interactions between attributes as defined by Aleks Jakulin in his work on attribute interactions. The interaction is defined as the difference between the sum of individual attribute information gains and the information gain of their cartesian product. The interaction can be negative (e.g. when the attributes are correlated), or positive (e.g. when the class is related to the xor of the two attributes).

The widget uses an external application for drawing graphs, GraphViz. It does not come with Orange, so you will need to install separately for the entire widget to work.

The widget will be completely redesigned in the nearest future, so we here only give its most basic description.

The widget is comprised of three parts. In the leftmost the user can select the attributes among which she or he wants to compute the interactions. The middle part contains all pairs of attributes - or all interesting pairs, if Show only important interactions is checked. For attributes which are in positive interaction, the blue parts at the left and the right end of the bar represent the individual information gains and the green part in the middle represents the interaction. For those in negative interaction, the red part is the interaction, which can be interpreted as the amount of information conveyed by both attributes, while the blue parts to the left and right are each attribute’s individual contribution.

The right part of the widget shows a graph of interactions.