Weka RemoveMisclassfied filter basics
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I am trying to find outliers and so I am trying to use RemoveMisclassfied filter in Weka. 
It is asking for a classification algorithm to base up on. say ZeroR Or R48.

Why is it asking for this to find misclassified items?  

When I look into the data , I can see that all the data is classified correctly (say 0/1 in resultant output variable). When I executed the filter, some of my dataset rows disappeared.

Basically, what is the logic behind this filtering?

Couldn't find an example. Please explain or direct me to a suitable source.

Thanks.