Descending from the family of simple probabilistic classifiers, Naive Bayes is a
popular method for text classification i.e. it judges the belonging of documents in their
respective categories (such as sports or politics, healthy or sick etc.) on the basis of word
frequencies as the features [48]. Based on the Bayesian theorem, this classifier assumes
the presence (or absence) of a particular feature of a class is unrelated to the presence (or
absence) of any other feature. For example, an orange is a fruit with distinctive features
of orange in color, round and about 4’ in diameter. Now irrespective of other features
present or the fact that these features may be dependent on each other, a Naive Bayes
classifier would consider all of these properties to independently contribute to the
probability that the given fruit is an orange. This type of classifier is henceforth useful in
medical diagnosis, since it would work very well with diseases showing similar
symptoms. Further, it is also capable of working well with a small amount of training
data to estimate the parameters (means and variances of the variables) necessary for
classification. Other advantages of using Naive Bayes classifier include its non-
sensitivity to irrelevant features, its capability to handle real, discrete and streaming data