search for: fleiss

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 appre...

Win7, R2.11.0 I am working on a report together with several co-authors. The data concern several performance measures on a set of groups. These measures are scored by external judges. We report findings on several datasets, including several of the 6 ICC's discussed by Shrout & Fleiss (1979). We determine these using the icc function from the irr package. We have also used the ICC function from the psych package. However, one of the datasets has varying numbers of judges for each group. One group may be rated by 2 judges, whereas others may even have ratings by up to 5 judges....

Dear R-colleagues, I am quite a newbie to R fighting my stupidity to solve a probably quite simple problem of generating artificial data with defined features. I am conducting a study of inter-observer-agreement in child-bronchoscopy. One of the most important measures is Kappa according to Fleiss, which is very comfortable available in R through the irr-package. Unfortunately medical doctors like me don't really understand much of statistics. Therefore I'd like to give the reader an easy understandable example of Fleiss-Kappa in the Methods part. To achieve this, I obtained a table...

Hello Everyone I am calculating Fleiss Kappa, I have 28 raters, 5 Subjects and 5 ratings. The problem is that there are 2 missing values in the data. Would it better to replace those with "0" or should those be omitted? By omission I will be left wit only 3 subjects. and my second problem is that overall agreement comes to...

...survey) as columns, each case (identified by the two columns "number of medical doctor" and "number of video") in a row. In addition there is a medical doctor number 21 who is assumed to be a gold-standard. As measure of inter-observer-agreement I calculated kappa according to Fleiss and simple agreement in percent using the routines "kappam.fleiss" and "agree" from the irr-package. Everything worked fine so far. Now I'd like to calculate specificity, sensitivity and accuracy for each item (compared to the gold-standard), as these are well-known and eas...

...latex example finn text html latex example icc text html latex example iota text html latex example kappa2 text html latex example kappam.fleiss text html latex example kappam.light text html latex example kendall text html latex example maxwell text html latex example meancor text...

...2.67081 12 6 2 2.63919 13 7 1 0.09050 14 7 2 0.03950 15 8 1 0.44019 16 8 2 0.30981 17 9 1 0.59000 18 9 2 0.57000 19 10 1 4.03000 20 10 2 3.77000 Variable i is for patient, j is for occasion, and x is measured on each occasion. These data have the same mean and variance listed on page 9 of Fleiss's book, Design and Analysis of Clinical Experiments, given below: > lapply(split(iccdata$x,iccdata$i),function(x){c(mean(x),var(x))}) $"1" [1] 0.23500000 0.02650062 $"2" [1] 0.1150000000 0.0004999122 $"3" [1] 0.1400 0.0008 $"4" [1] 0 0 $"5&qu...

R Experts: I am conducting a meta-analysis where the effect measures to be pooled are simple proportions. For example, consider this data from Fleiss/Levin/Paik's Statistical methods for rates and proportions (2003, p189) on smokers: Study N Event P(Event) 1 86 83 0.965 2 93 90 0.968 3 136 129 0.949 4 82 70 0.854 Total 397 372 A test of heterogeneity for a ta...

A new package, ridittools, is available on CRAN Description: Functions to compute ridit scores of vectors, compute mean ridits and their standard errors for vectors compared to a reference vector,as described in Fleiss (1981, ISBN:0-471-06428-9), and compute means/SEs for multiple groups in matrices. Data can be either counts or proportions. Emphasis is on ridit analysis of ordered categorical data such as Likert items and pain-rating scales. _______________________________________________ R-packages mailing lis...

...ifferences between malignant and benign more than differences between malignant and probably malignant. I only found the weighted option in the 2-rater functions (kappa2, wkappa, cohen.kappa). The functions I found for multiple raters do not include a weighted option for categorical data (kappam.fleiss, kappam.light, lkappa). Anyone know a function that allows the calculation of weighted kappa for m raters? Thanks in advance! ~Marwa [[alternative HTML version deleted]]

A new package, ridittools, is available on CRAN Description: Functions to compute ridit scores of vectors, compute mean ridits and their standard errors for vectors compared to a reference vector,as described in Fleiss (1981, ISBN:0-471-06428-9), and compute means/SEs for multiple groups in matrices. Data can be either counts or proportions. Emphasis is on ridit analysis of ordered categorical data such as Likert items and pain-rating scales. _______________________________________________ R-packages mailing lis...

Dear R-help, I'm using prop.test() to compute a confidence interval for a proportion under R version 2.4.1, as in: prop.test(x = 340, n = 400)$conf [1] 0.8103309 0.8827749 I have two questions: 1) from the source code my understanding is that the confidence interval is computed according to Wilson, E.B. (1927) Probable inference, the law of succession, and statistical inference. J. Am.

Dear R-colleagues, another question from a newbie: I am creating a lot of simple pivot-charts from my raw data using the reshape-package. In these charts we have medical doctors judging videos in the columns and the videos they judge in the rows. Simple example of chart/data.frame "input" with two categories 1/0: video 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 1 1 0 0