Displaying 20 results from an estimated 2000 matches similar to: "cohen's kappa"
2006 Dec 11
1
cohen kappa for two-way table
Greetings,
I am a bit confused by the results returned by the functions:
cohen.kappa {concord}
classAgreement {e1071}
when using a two-way table.
for example, if I have an matrix A, and a similar matrix B (same
dimensions), then:
matrix A and B can be found:
http://casoilresource.lawr.ucdavis.edu/drupal/files/a_40.txt
http://casoilresource.lawr.ucdavis.edu/drupal/files/b_40.txt
A <-
2007 Mar 22
3
Cohen's Kappa
Hi,
im little bit confused about Cohen's Kappa and i should be look into the
Kappa function code. Is the easy formula really wrong?
kappa=agreement-chance/(1-chance)
many thanks
christian
###############################################################################
true-negativ:7445
false-positive:3410
false-negativ:347
true-positiv:772
classification-aggrement:68,6%
2006 Apr 28
1
Where do I find Cohen´s kappa???
Hello,
I?m looking for a way to measure the goodness of fit of my model with Cohen?s Kappa (scaling between 0 and 1).
The kappa function does not give the results I?m looking for. Heres the code:
z<-glm(x~y,binomial)
kappa(z, exact = T)
Does anyone know more?
many thanks
Christian
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Search for businesses by name, location, or phone number.
2010 May 25
1
Cohen's Kappa for beginners
Hi,
I've got two vectors with ratings from two coders, like this:
x<-c("red", "yellow", "blue", "red") #coder number 1
y<-c("red", "blue", "blue", "red") #coder number 2
I want to find Cohen's Kappa using the wkappa function in the psych
package. The only example in the docs is using a matrix, which
2009 Dec 22
1
Cohen's kappa, unequal score ranges
Hi,
I am having problems getting cohen's kappa to work. I have been using the function:
><-ckappa(x,y)
from the psy package.
I am trying to test for inter-observer reliability, I have 2 observers and 26 categories, however, the two observers might not necessarily have the same range of categories (I have unequal score ranges). However, I thought R could cope with this.
Each time I
2006 Oct 02
2
R function to compute kappa statistics for two vector
Dear R-user,
Did anybody know how to calculate the kappa statistics of two vectors for
the agreement? for example:
a<-c(0,1,0,0,1,0)
b<-c(0,1,1,0,0,1)
I know the percent of agreement is 3/6, but how to get the kappa?
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2002 Feb 05
2
Measures of agreement
Greetings.
I've been experimenting with some algorithms for document classification
(specifically, a Naive Bayes classifier and a kNN classifier) and I would
now like to calculate some inter-rater reliability scores. I have the data
in a PostgreSQL database, such that for each document, each measure (there
are 9) has three variables: ap_(measure), nb_(measure), and
knn_(measure). ap is me
2008 Oct 31
1
stratified kappa (measure agreement or interrater reliability)?
Hi All:
Could anyone point me to a package that can calculate stratified kappa? My
design is like this, 4 raters, 30 types of diagnosis scores, 20 patients.
Each rater will rate each patient for each type of diagnosis score. The
rater's value is nominal.
I know I can measure the agreement between raters for each type of diagnosis
score, e.g., calculate out 30 kappa values. My problem is I
2007 Jun 26
3
inter-rater agreement index kappa
Is there a function that calculates the inter-rater agreement index
(kappa) in R?
Thanks ../Murli
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2005 Jun 05
5
A long digression on packages
Hello again,
First, thanks for the help that got the latest plotrix package finished.
I had been planning to write something about packages since Scott
Waichler offered the gantt.chart function. Then Ben Bolker (who helped
me to write the axis.break function) asked if I would be willing to
include some of his plotting functions and almost immediately after that
Sander Oom kindly donated the
2005 Jun 05
5
A long digression on packages
Hello again,
First, thanks for the help that got the latest plotrix package finished.
I had been planning to write something about packages since Scott
Waichler offered the gantt.chart function. Then Ben Bolker (who helped
me to write the axis.break function) asked if I would be willing to
include some of his plotting functions and almost immediately after that
Sander Oom kindly donated the
2011 Jun 22
1
caret's Kappa for categorical resampling
Hello,
When evaluating different learning methods for a categorization problem with
the (really useful!) caret package, I'm getting confusing results from the
Kappa computation. The data is about 20,000 rows and a few dozen columns,
and the categories are quite asymmetrical, 4.1% in one category and 95.9% in
the other. When I train a ctree model as:
model <- train(dat.dts,
2007 Apr 24
5
intersect more than two sets
Hi,
I searched the archives and did not find a good solution to that.
assume I have 10 sets and I want to have the common character elements of them.
how could i do that?
--
Weiwei Shi, Ph.D
Research Scientist
GeneGO, Inc.
"Did you always know?"
"No, I did not. But I believed..."
---Matrix III
2009 Jul 13
3
Help With Fleiss Kappa
Hi All,
I am using fleiss kappa for inter rater agreement. Are there any know
issues with Fleiss kappa calculation in R? Even when I supply mock data
with total agreement among the raters I do not get a kappa value of 1.
instead I am getting negative values.
I am using the irr package version 0.70
Any help is much appreciated.
Thanks and Regards
M
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2007 Apr 11
5
how to reverse a list
Hi, there:
I am wondering if there is a quick way to "reverse" a list like this:
t0 <- list(a=1, b=1, c=2, d=1)
reverst t0 to t1
> t1
$`1`
[1] "a" "b" "d"
$`2`
[1] "c"
thanks.
--
Weiwei Shi, Ph.D
Research Scientist
GeneGO, Inc.
"Did you always know?"
"No, I did not. But I believed..."
---Matrix III
2007 Jun 25
3
a string to enviroment or function
Hi,
I am wondering how to make a function Fun to make the following work:
t0 <- (paste("hgu133a", "ENTREZID", sep=""))
xx <- as.list(Fun(t0)) # make it work like xx<-as.list(hgu133aENTREZID)
thanks,
--
Weiwei Shi, Ph.D
Research Scientist
GeneGO, Inc.
"Did you always know?"
"No, I did not. But I believed..."
---Matrix III
2005 Aug 05
1
kappa-accuracy and test for signifcance
Dear list,
I calculated the kappa-accuracy for two differnt classifications.
How can I test now the two kappa-value for significance?
thanks, Mark
.....................................................................
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Wissenschaftliche Mitarbeiterin
Eidg. Forschungsanstalt WSL
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Z??rcherstrasse 111
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Fax
2010 Nov 17
2
statistical test for comparison of two classifications (nominal)
Dear all,
I am having a hard time to figure out a suitable test for the match
between two nominal classifications of the same set of data.
I have used hierarchical clustering with multiple methods (ward,
k-means,...) to classify my dat into a set number of classesa, and I
would like to compare the resulting automated classification with the
actual - objective benchmark one.
So in principle I
2008 Aug 24
2
similarity between two gene lists with varied length
Dear listers,
a little off-topic:
I am looking for and compare algorithms which can calculate "distance" or
"similarity" between two gene lists with different lengths.
Any paper, any implementation in R and any suggestion is welcome!
Thanks,
--
Weiwei Shi, Ph.D
Research Scientist
GeneGO, Inc.
"Did you always know?"
"No, I did not. But I believed..."
2006 Oct 17
4
cluster in R
hi,
is there some good summary on clustering methods in R? It seems there
are many packages involving it.
And I have two questions on clustering here:
1. Is there a way of evaluate the effecitives (or seperation) of
clustering (rather than by visualization)?
2. Is there a search method (like genetic search) which can help find
the best subset of attributes which gives best seperation?
Thanks,