Slimming a model
Consider the table model shown here (it is provided in the file 'Vehicles table' in the Examples folder).
How will InterModeller use this model to identify an unknown vehicle? Because it investigates tables in column order, InterModeller will first question for the No of wheels and then question for Fuel. However, a strategy which always asks these two questions is inefficient. Ideally, the attribute that should be elicited first is Fuel. This is because its value may turn out to be Diesel or Leg-power, in which cases the vehicle can be identified immediately, without having to ask about No of wheels.
Here is a version of the vehicles model that InterModeller will run using the more efficient strategy.
The columns have been re-sequenced and some information (the No of wheels values for Van and Bicycle) has been discarded. This 'slimmer' model is capable of classifying a Van and a Bicycle each in only a single question. The model could of course be obtained manually by editing the original model. However, InterModeller is capable of generating it automatically. This can be done by using the 'Slim to essentials' option of the Transform dialogue (Build menu).
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This suggests the general idea of slimming. The aim is to create a version of the model which runs more efficiently as a classification procedure - one that gives the same answers on the same data, but with fewer questions. Models often contain more information than is strictly necessary to distinguish between the classes of things that they describe. Slimming a model eliminates this surplus information and re-sequences the remaining information so that a class can be recognised with the minimum of questioning.