Comment by 1024core
2 years ago
True. You want to always use an odd number so there are no ties.
I'm guessing they were trying a parameter sweep, and found that (thanks to the bug) they got the best results for K=2.
This too is problematic in its own sense.
Yes, agreed. One small point: for the multi-class case (more than just two classes), which include all the datasets here, you can still get ties for odd k. e.g. k=3, you can get 1 vote each for 3 different classes, etc.
Multi-class is trickier. Maybe we can break down an N-class problem into N binary-classification problems?