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How to scale up underrepresented classes from Dataset?

Fred12Fred12 Member Posts: 344   Unicorn
edited November 2018 in Help

hi,

I have 5000 data exemplars with 3 classes... but distribution of the classes (1 , 2, 3) are about 50/30/20 ... classification of 2 and 3 is rather poor compared to 1.. to achieve better classification results for them I used MetaCost for weighting class 2 and 3 in the testing / prediction process.... 

but I would also like to do weighting of the classes 2 or 3 in the learning process of the model... before testing, how can I do that? is there a way to scale up my underrepresented classes with an operator? or what are good weighting functions for learning models? 

Answers

  • Thomas_OttThomas_Ott RapidMiner Certified Analyst, RapidMiner Certified Expert, Member Posts: 1,761   Unicorn

    There a few ways to do that. One is the use the Sample operator and toggle on "Balance Data." From there you can set the class size you want. Of course, you can use the Sample by Bootstrapping operator as well.  

     

    If you weight your classes, you can use the Select By Weights operator as well. Many different ways to do this in Studio. Good luck. 

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