RE: precision/recall

[Subbarao Kambhampati <rao@asu.edu>]

At 09:36 PM 1/27/2004, you wrote:

> So further using your
> example...
>
> So if I wanted to build a model from the example below I have three
> points
> where the recall is 2/7 and two points where the recall is 1/7; however,
> the
> precision varies.  So if I was to graph it would I plot the
> precision at 1,
> 1/2, or 3/4 (the average) when the recall is 2/7?  I'm sorry, maybe
> I'm not
> completely understanding you.  Thanks.


you have basically three (r,p) points--(1,1/7); (1/2,1/7); (2/3,2/7) (as
per the discussion below)--
each ith point corresponding to the r/p values for top i results seen.
You plot these points and draw a curve through them
you get precision/recall curve

> if you look at first
> document alone
>
>  precision is 1 and recall is 1/7
>
> after D1,D2
>  precision is 1/2   and recall is 1/7 
>
> after D1,D2,D3
>
> precision is 2/3   and recall is
> 2/7