WHAT IS C4.5?

• C4.5 is developed by J. Ross Quinlan in 1992

  
  

• Evolved from ID3, an earlier decision tree software package developed by Quinlan

  
  

• Splitting rule:

  
  

  • A combination of information gain and gain ratio criteria

    
    

  • Select the maximum gain ratio split while maintaining a higher than average information gain

    
    

• Stopping rule:

  
  

  • Stop when node is pure

    
    

  • Stop when no more splits can be found

    
    

• Pruning rule

  
  

  • Pessimistic pruning

    
    

  • Default confidence limit is 25%