Suggestions

Thanks for your comments.

1. Sure.

2. I will try to add some explanation.

3. I guess the reason is that spam ratio in Ling-Spam is much lower, therefore the performance of NB is much worse. Also, since the size of data is small, the variance of classification results can be high.

4. I think it should precision, because it measure false positive (incorrectly rejecting legitimate email), which is a big problem for email users.

Yan