Hi, hope someone can comment on my reasoning (due to lack of
confidence in statistics) on this probability problem:
I want to find the joint probability of a hierarchical classifier
system. It consists of 4 individual classifiers C1, C2, C3 and C4:

    C1
    |
---------
|   |   |
C2  C3  C4

C1 classifies between groups {a,b},{c,d,e} and {f,g}
C2 classifies between a and b
C3 classifies between c, d and e
C4 classifies between f and g

So, in order to classify an item (e.g. f) correctly it is required
that C1 classifies correcly such that the next classifier to be
invoked is C4 (that classifies between f and g).

I have the individual classification rates and the confusion matrices
for each classifier - but I am not sure how to compute the "joint"
probability..

The individual classification rates are as follows:

C1: classification rate: 99.36%
Confusion matrix: 
 400  0    0
 0    596  4
 0    5    395
(as you see there are 400 of type {a,b}, 600 of {c,d,e} and 400 of
{f,g}.)

C2: classification rate: 100%
C3: classification rate: 99.33%
C4: classification rate: 86.0%

Can I simply calculate the joint probability as:

P = (400*0.9936*1.0 + 596*0.9936*0.9933 + 395*0.9936*0.86 ) /
(400+596+395)
P = 95.12

???
I would appreciate any comments on the correctness of this :)

Many Thanks

McIlfar
.
.
=================================================================
Instructions for joining and leaving this list, remarks about the
problem of INAPPROPRIATE MESSAGES, and archives are available at:
.                  http://jse.stat.ncsu.edu/                    .
=================================================================

Reply via email to