Preferences

The PyXAI library offers the possibility to process user preferences. Different kinds of preferences are handled:

• The user may prefer some explanations to others.
• The user may exclude some features from explanations.

More information about preferences can be found in the paper On Preferred Abductive Explanations for Decision Trees and Random Forests .

Preferred reasons

In this case, the user has to provide a weight for each feature, representing its disutility (or cost). The PyXAI library offers different options:

• PreferredReasonMethod.SHAPLEY: Only available with Scikit-learn. It uses Shapley values to discriminate features. See this paper for more information.
• PreferredReasonMethod.FEATURE_IMPORTANCE: Only available with Scikit-learn. It uses the f-importance of features to discriminate them. See this paper for more information.
• PreferredReasonMethod.WORD_FREQUENCY: It uses the wordfreq package to discriminate features. The more frequent is a word in a feature name, the more likely it is to be understood by users.
• PreferredReasonMethod.WEIGHTS: The user defines the the weights to be used.
• PreferredReasonMethod.INCLUSION_PREFERRED: The user has to define a partition over all features
• (a list of list). The first elements of the partition are preferred to the second ones which are preferred to the third ones and so on.

Excluded features

Eecluding some features from explanations can be achieved using the function set_excluded_features. The function unset_excluded_features allows to restore the initial state (where default there is no excluded features).

It may happen that excluded features prevent from computing explanations. In this case, the method that computes the explanation will return [].