Add Interaction Effect Fields
If it has been identified that Interaction Effects exist in the data, the user may want to create new fields in their Training Data to represent those Interaction Effects. These new fields can be created within the Interaction Effects window.
There are three different ways to create new fields within the Training Data in SQL from the Interaction Effects window:
To create this type of field, double click on either the row or column label. For all records where the bin equals that of the double clicked bin, a field will be created that equals the bin of the other characteristic being compared in the matrix. For all remaining records (those that do not contain the value/bin that was double clicked) a value of 'NULL' is assigned.
In the grid above, double clicking on the 'A' will create a new field that is set to the value of Char2 ('X' or 'Y') for all the records where Char1 is equal to 'A' and 'NULL' for all the records where Char1 is not equal to 'A'. A window will pop up asking the user to choose a name for the new field, with an intelligent default.
To create this type of field, double click on the number in the cell of the desired intersection. A field will be created that equals TRUE for all records that fall into both of the bins of the selected intersection and FALSE for all other records.
In the grid above, double clicking on the '0.0146' will create a new field that equals TRUE for all records where Char1 is equal to 'A' and Char2 is equal to 'X', and FALSE for all other records.
To create this type of field, double click on the blank box in the upper left hand corner of the matrix. A field will be created that concatenates the values of the two intersected bins for all records.
In the grid above, a new field will be created containing the values 'A_X', 'A_Y', 'B_X', or 'B_Y' depending on the values of Char1 and Char2 for each record (because there are no NULL values in this example, there is no NULL_NULL, NULL_X, etc. field created).
After creating a new field as the result of discovering an interaction effect, the new field may be used in the next analysis run. Also, it is possible to create new fields that cross more than two characteristics by creating one new field via the Interaction Effects window, running an analysis with it, and then viewing the Interaction Effects a second time to cross the new field with yet another characteristic.