V i s i R e x S c r e e n s
VisiRex Rule Extraction
This is the final screen of the three screen rule extraction wizard.
The Back<< button moves you backward to row selection.>
The Finish>> button runs the extracted rules for all of your test data, then delivers you to reports.
The Confidence and Tree size are shown for the current tree.
Rule Extraction... Extraction Settings
- Experiment with the Prune Rate and Min Items while trying to obtain the simplest tree with the highest confidence.
This is an interactive, visual process.
- You must subjectively decide how simple a tree you desire and how confident a prediction you require, depending on the specific purpose of this project.
- Remember to press Extract Rules Now button to refresh the tree to your latest settings.
- When you are satisfied with the extracted rules, press Finish>> to complete the process.
- If your tree becomes too wide (200-300 nodes) the flow chart view is not available and you must work in tree chart view.
- The Prune Rate is the most intelligent way to prune, as it goes to the heart of the entropy calculations.
- The Min Items is a crude way of pruning, as it simply ignores cases that occur less frequently than this minimum setting.
The use of Min Items works best on large or noisy databases, where you wish to discourage the extraction of trivial rules to explain small amounts of data.
- In practice, the optimal tree occurs at some combination of Prune Rate and Min Items.
Rule Extraction... Chart Control
- The Chart Control allows you to color the flow chart according to data quantity, prediction confidence or predicted class.
- The Chart Control also reports the data quantity and prediction confidence for the total tree and for any local node.
- The local node is the node currently beneath you mouse cursor.
A Complete System for Inductive Rule Extraction
CorMac Technologies Inc.
34 North Cumberland Street ~ Thunder Bay ON P7A 4L3 ~ Canada
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