-Bharath
Thursday, November 3, 2011
11/01/2011
Naive Byes classification makes lots of assumption and still works well. Though the probability estimates is of low quality, relative ordering of the class probabilities are correct i.e its classification decisions are good.
11/03/2011
To accomplish Diversity in Feature Selection
apply Mutual Information process twice.
As normal, calculate Mutual Information of word
and class. Do sort. Then determine next ranked
by computing the mutual Information from next highly
ranked word and the previous word.
--
10/1/11
To emphasize a point,
NBC with feature selection does
reduce the over-fitting problem with respect to f-measure.
Reason: No longer fixated on irrelevant features
as in case of taking almost every feature
Also:Fewer features has, of course ,faster calculation time.
M.
11/01/2011
NBC will compute probability highly erroneously, what matters is not the exact probability but the relative order. There are more cases where probabilities are wrong and relative order is correct.
-- Dinu
-- Dinu
10/27/2010
In NBC we learn probabilities from the data and it computes posterior probability distribution on the class. Here the assumption is classes directly cause attributes and there is no intermediary.
-- Dinu
-- Dinu
11/01/2011
Feedback detection can be intrusive and non-intrusive.
Intrusive detection is in a way explicitly asking the user to rate the items.
On the other hand, in non-intrusive detection, we follow the user actions.
-Sandeep Gautham
Intrusive detection is in a way explicitly asking the user to rate the items.
On the other hand, in non-intrusive detection, we follow the user actions.
-Sandeep Gautham
11/1/2011
NBC makes an assumption that all the attributes are independent of each other.
This reduces the computation of probabilities from n*d^k to n*d*k.
This reduces the computation of probabilities from n*d^k to n*d*k.
Where n is the number of classes, k is the number of attributes and d is the different values each of these attributes can take.
-Sandeep Gautham
-Sandeep Gautham
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