Processing Order for Rules

When text link analysis is performed during extraction, a "sentence" (clause, word, phrase) will be matched against each rule in turn until a match is found or all rules have been exhausted. Position in the tree dictates the order in which rules are tried. Best practice states that you should order your rules from most specific to most generic. The most specific ones should be at the top of the tree. To change the order of a specific rule or rule set, select Move up or Move down from the Rules and Macro Tree context menu or the up and down arrows in the toolbar.

If you are in the source view, you cannot change the order of the rules by moving them around in the editor. The higher up the rule appears in the source view, the sooner it is processed. We strongly recommend reordering rules only in the tree to avoid copy/paste issues.

Important! In previous versions of IBM® SPSS® Modeler Text Analytics, you were required to have a unique, numeric rule ID. Starting in version 18.6.0, you can only indicate processing order by moving a rule up or down in the tree, or by their position in the source view.

For example, suppose your text contains the following two sentences:

I love anchovies

I love anchovies and green peppers

In addition, suppose that two text link analysis rules exist with the following values:

Figure 1. 2 Example Rules
2 Example Rules

In the source view, the rule values might look like the following:

A: value = $Positive $mDet? $mTopic

B: value = $Positive $mDet? $mTopic ($SEP|and|or){1,2} $mDet? $mTopic

If rule A is higher up in the tree (closer to the top) than rule B, then rule A will be processed first and the sentence I love anchovies and green peppers will be first matched by $Positive $mDet? $mTopic, and it will produce an incomplete pattern output (anchovies + like) since it was matched by a rule that wasn't looking for 2 $mTopic matches.

Therefore, to capture the true essence of the text, the most specific rule, in this case B must be placed higher in the tree than the more generic one, in this case rule A.