naive bayes probleam

haviv

hello,
i have probleam using naive bayes. i train database with naivebayes, and after it i apply the model on a test data base. i the results, not all instances was classified. the unclassified instances get "?" in the prediction and confidnce at the result. what could be the probleam?

thank you, haviv

ForestG

this is really similar to my problem (few threads up). If you look at the test data, does it contain "?" values?

MariusHelf

Does the test data contain nominal values that do not occur in the training data? Or do you have missing values in your test data? In that case Naive Bayes can't deliver proper predictions.

Best regards,
Marius