I have a training set and a testing set which I want to classify with Weka. and because my attribute is a text .. I understand that I have to apply first the stringtoword filter first. As has been described here, I have to do the following: 1- load the train and test sets and apply the filter. 2- Train the classifier using the training set and save the model. 3- Load the model to apply it on the testing set.
I my experiment I have to use the trained classifier to test multiple test sets .. so, do I have to repeat 1,2 and 3 or I can repeat the third step only ?
and do I have to replace the class in testing set with a question mark (?) or I can leave the class their and the classifier will try to predict the class anyway?