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= Selection and Reduction = 
Selectors are HeuristicLab 3.3 operators that implement the `ISelector` interface. Likewise, Reducers implement the `IReducer` interface.

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[=#Selection]
== 1. Selection Operators == 

'''Common Operator Parameters:'''
||= Parameter         =||= Description =||
|| !CopySelected || True if the selected sub-scopes should be copied, otherwise false. ||
|| !CurrentScope || The current scope from which sub-scopes should be selected. ||
|| Maximization || True if the current problem is a maximization problem, otherwise false. ||
|| !NumberOfSelectedSubScopes || The number of sub-scopes which should be selected. ||
|| Quality || The quality value contained in each sub-scope which is used for selection. ||

=== 1.1 !BestSelector ===
A selection operator which considers a single double quality value and selects the best.

=== 1.2 !GenderSpecificSelector ===
Brings two parents together by sampling each with a different selection scheme (Wagner and Affenzeller 2005).

=== 1.3 !LinearRankSelector ===
A linear rank selection operator which considers the rank based on a single double quality value for selection.

=== 1.4 !ProportionalSelector ===
A quality proportional selection operator which considers a single double quality value for selection.

=== 1.5 !RandomSelector ===
A random selection operator.

=== 1.6 !TournamentSelector ===
A tournament selection operator which considers a single double quality value for selection.

=== 1.7 !WorstSelector ===
A selection operator which considers a single double quality value and selects the worst.

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[=#Reduction]
== 2. Reduction Operators == 

'''Common Operator Parameters:'''
||= Parameter         =||= Description =||
|| !CurrentScope || The current scope from which sub-scopes should be selected. ||

=== 2.1 !LeftReducer ===
An operator which reduces to the sub-scopes of the leftmost sub-scope of the current scope.

=== 2.2 !MergingReducer ===
An operator which reduces to the sub-scopes of all sub-scopes of the current scope.

=== 2.3 !RightChildReducer ===
Merges all sub-scopes generated by successively selecting sub-scopes of the remaining part.

=== 2.4 !RightReducer ===
An operator which reduces to the sub-scopes of the rightmost sub-scope of the current scope.

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== References ==
 * Wagner, S. and Affenzeller, M. 2005. SexualGA: Gender-Specific Selection for Genetic Algorithms. Proceedings of the 9th World Multi-Conference on Systemics, Cybernetics and Informatics (WMSCI), pp. 76-81.