UGC NET 1996

[Sangeeta Dubey]

Q.1 :- There are a total of 50 relevant document in a collection. In response to a query,only 30 document are retrieved, of these ,only 10 were relevant.What is the recall percentage.
Ans:-
A} 20%
B} 33%
C} 40%
D} 60%

Ans :- B} 33%

Dear lis professionals,
Can anyone tell me how to get this answer?
Is their any method?

[Langmuanjohn Tonsing]

hello Sangeeta,

Let me give a try

Formula is Recall = Number of relevant result retrieve / Number of non-retrieve document + Number of relevant result retrieve

so, Number of relevant result retrieve=10,

     Number of non-retrieve documents=20 (50-30=20)

Recall=10/20+10

         =10/30

         = 0.33

         =0.33*100=33% (i.e. 33/100=0.33)

This is wat i think according to the formula, if it is wrong let me know.

[Langmuanjohn Tonsing]

Sori, the last line " =0.33*100=33% (i.e. 33/100=0.33)" should be =0.33 =33% (i.e. 33/100=0.33).

[Vishal Sharma]

10*100/30=33.33%

[Langmuanjohn Tonsing]

Dear Vishal Sharma 

Can you please explain in details?

[Dr.Harmanpreet Singh Sandhu]

Very Good Question asked, with regards to upcoming pattern of the UGC NET June 2012.   Recall percentage is the percentage of documents retrieved which were of actually requested or relevant documents with reference to the query.

To find out the Recall % = Total no. of relevant documents delivered / Total no. of documents deliverd * 100

  i:e   10/30*100 = 33.33 %

When searching in google we don't know the total relevant documents uploaded on the net ..... so the recall % is found out by this formula only.

[Langmuanjohn Tonsing]

Dear Harmanpreet,

Can you also please give the formula for precision?

[Sangeeta Dubey]

Lot of thanks for your opinion.

[Vishal Sharma]

welcome ma'am

[K. Nagaraja Rao]

According to me: Recall is intersection of relevant documents and retrieved documents divided by relevant documents in the system:

thus the intersection gives only 10 out of 50 relevant documents. 1/5*100

Which is 20%. To get 33%, the question should say 30 relevant documents from a total collection.

formula taken from wikipedia.

[Sangeeta Dubey]

Thank you for your efforts sir.

I ll check it. n inform you.

[rawish]

mam if u got the recall value for your questions plz tell me the correct answer and also the method.thanks