Gad Abraham wrote:
Frank E Harrell Jr wrote:
Gad Abraham wrote:
This approach leaves much to be desired. I hope that its
practitioners start gauging it by the mean squared error of
predicted probabilities.
Is the logic here is that low MSE of predicted probabilities equals a
better
Gad Abraham wrote:
This approach leaves much to be desired. I hope that its
practitioners start gauging it by the mean squared error of predicted
probabilities.
Is the logic here is that low MSE of predicted probabilities equals a
better calibrated model? What about discrimination? Perfect
This approach leaves much to be desired. I hope that its practitioners
start gauging it by the mean squared error of predicted probabilities.
Is the logic here is that low MSE of predicted probabilities equals a
better calibrated model? What about discrimination? Perfect calibration
implies
Frank E Harrell Jr wrote:
Gad Abraham wrote:
This approach leaves much to be desired. I hope that its
practitioners start gauging it by the mean squared error of predicted
probabilities.
Is the logic here is that low MSE of predicted probabilities equals a
better calibrated model? What
Gabor Grothendieck wrote:
On Mon, Oct 13, 2008 at 11:47 PM, Frank E Harrell Jr
[EMAIL PROTECTED] wrote:
Gabor Grothendieck wrote:
On Mon, Oct 13, 2008 at 11:21 PM, Frank E Harrell Jr
[EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
I recall a concept of Snout: sensitivity that is high
Dear Mr Peter Dalgaard and Mr Dieter Menne,
I sincerely thank you for helping me out with my problem. The thing is taht I
already have calculated SENS = Gg / (Gg + Bg) = 89.97%
and SPEC = Bb / (Bb + Gb) = 74.38%.
Now I have values of SENS and SPEC, which are absolute in nature. My question
.
Kind Regards,
Pedro
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
On Behalf Of Maithili Shiva
Sent: Monday, October 13, 2008 3:28 AM
To: r-help@r-project.org
Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: [R] Fw: Logistic regresion - Interpreting (SENS) and (SPEC
Pedro.Rodriguez at sungard.com writes:
There are two good papers that illustrate how to compare classifiers
using Sensitivity and Specificity and their extensions (e.g., likelihood
ratios, young index, KL distance, etc).
See:
1) Biggerstaff, Brad, 2000, Comparing diagnostic tests: a
Maithili Shiva wrote:
Dear Mr Peter Dalgaard and Mr Dieter Menne,
I sincerely thank you for helping me out with my problem. The thing is taht I
already have calculated SENS = Gg / (Gg + Bg) = 89.97%
and SPEC = Bb / (Bb + Gb) = 74.38%.
Now I have values of SENS and SPEC, which are absolute in
Jumping into a thread can be like jumping into a den of lions but here goes . .
.
Sensitivity and specificity are not designed to determine the quality of a fit
(i.e. if your model is good), but rather are characteristics of a test. A test
that has high sensitivity will properly identify a
John Sorkin wrote:
Jumping into a thread can be like jumping into a den of lions but here goes . .
.
Sensitivity and specificity are not designed to determine the quality of a fit (i.e. if your model is good), but rather are characteristics of a test. A test that has high sensitivity will
Frank,
Perhaps I was not clear in my previous Email message. Sensitivity and
specificity do tell us about the quality of a test in that given two tests the
one with higher sensitivity will be better at identifying subjects who have a
disease in a pool who have a disease, and the more sensitive
John Sorkin wrote:
Frank,
Perhaps I was not clear in my previous Email message. Sensitivity and specificity do tell us about the quality of a test in that given two tests the one with higher sensitivity will be better at identifying subjects who have a disease in a pool who have a disease, and
- Original Message -
From: Frank E Harrell Jr [EMAIL PROTECTED]
To: John Sorkin [EMAIL PROTECTED]
Cc: r-help@r-project.org; [EMAIL PROTECTED];
[EMAIL PROTECTED]
Sent: Monday, October 13, 2008 2:09 PM
Subject: Re: [R] Fw: Logistic regresion - Interpreting (SENS) and (SPEC)
John
PROTECTED]
To: John Sorkin [EMAIL PROTECTED]
Cc: r-help@r-project.org; [EMAIL PROTECTED];
[EMAIL PROTECTED]
Sent: Monday, October 13, 2008 2:09 PM
Subject: Re: [R] Fw: Logistic regresion - Interpreting (SENS) and (SPEC)
John Sorkin wrote:
Frank,
Perhaps I was not clear in my previous Email message
John Sorkin wrote:
Of course Prof Baer is correct the positive predictive value (PPV)
and the negative predictive values (NPV) serve the function of
providing conditional post-test probabilities PPV: Post-test
probability of disease given a positive test NPV: Post-test
probability of no disease
Indeed, however as I stated in my prior Email, the cases of a 0 or 1
prevalence are degenerative and are of little practical importance. And
as noted in my EMail message, I was talking about values of PPV and NPV
as a function of sensitivity and specificity when the prevalence is
fixed.
John
? And the higher the specificity, the greater the PPV?
http://www.musc.edu/dc/icrebm/diagnostictests.html
--Chris Ryan
Original message
Date: Mon, 13 Oct 2008 18:14:39 -0400
From: John Sorkin [EMAIL PROTECTED]
Subject: Re: [R] Fw: Logistic regresion - Interpreting(SENS
: Monday, October 13, 2008 4:14 PM
To: Ph.D. Robert W. Baer; Frank E Harrell Jr
Cc: r-help@r-project.org; [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: [R] Fw: Logistic regresion - Interpreting (SENS) and (SPEC)
Of course Prof Baer is correct the positive predictive value (PPV) and the
negative
/diagnostictests.html
--Chris Ryan
Original message
Date: Mon, 13 Oct 2008 18:14:39 -0400
From: John Sorkin [EMAIL PROTECTED]
Subject: Re: [R] Fw: Logistic regresion - Interpreting (SENS) and (SPEC)
To: Ph.D. Robert W. Baer [EMAIL PROTECTED], Frank E Harrell Jr [EMAIL PROTECTED]
Cc: r-help@r
PM
- Original Message -
From: Frank E Harrell Jr [EMAIL PROTECTED]
To: John Sorkin [EMAIL PROTECTED]
Cc: r-help@r-project.org; [EMAIL PROTECTED];
[EMAIL PROTECTED]
Sent: Monday, October 13, 2008 2:09 PM
Subject: Re: [R] Fw: Logistic regresion - Interpreting (SENS) and (SPEC)
John
PROTECTED]
To: John Sorkin [EMAIL PROTECTED]
Cc: r-help@r-project.org; [EMAIL PROTECTED];
[EMAIL PROTECTED]
Sent: Monday, October 13, 2008 2:09 PM
Subject: Re: [R] Fw: Logistic regresion - Interpreting (SENS) and (SPEC)
John Sorkin wrote:
Frank,
Perhaps I was not clear in my previous Email
Gabor Grothendieck wrote:
On Mon, Oct 13, 2008 at 11:21 PM, Frank E Harrell Jr
[EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
I recall a concept of Snout: sensitivity that is high enough to
essentially rule out the presence of disease. And Spin: specificity that
is high enough to
On Mon, Oct 13, 2008 at 11:47 PM, Frank E Harrell Jr
[EMAIL PROTECTED] wrote:
Gabor Grothendieck wrote:
On Mon, Oct 13, 2008 at 11:21 PM, Frank E Harrell Jr
[EMAIL PROTECTED] wrote:
[EMAIL PROTECTED] wrote:
I recall a concept of Snout: sensitivity that is high enough to
essentially rule
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