The Intra-class Correlation Coefficient measures the degree to which a categorical variable accounts for variability in a continuous variable. It is often used to index the degree of clustering in a dataset.

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Metaanalysis - how big should be the ICC (Intracluster correlation coefficient)?

The background is a metaanalysis of cluster randomised clinical studies. The included studies report no ICC for final values, the chosen ICC for the calculations was 0,02. Similar studies in the same ...
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10 views

Intraclass correlation (ICC) single vs average measure?

I think I need help understanding single-measurement ICC and its difference to average-measurement ICC. Assume I have the following situation: I have a specific rater I am interested in. I want to ...
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17 views

Analysis and Processing of Time Series Data

My project requires me to accurately analyze several (15) financial time series data - Indicators. The data consist mostly of several variants of moving average and stochastic information (ie ...
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15 views

Can I use ICC and bland altman plot to study agreement of small data?

I have data set with small sample size, like 10 pairs of continuous data. I checked out kappa and percentage agreement, both seems not appropriate for agreement analysis. Can I stick to use ICC and ...
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38 views

Calculate p-value for difference between ICC values

I cannot seem to find an answer to the following problem: I am doing interreader correlation studies where I calculate ICC values. It is quite easy to do this in R, but how do I calculate a p-value to ...
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19 views

Find general correlation between function with itself and other input data

I've collected data for a function F = f(g(x)), for different function shapes g(x). The goal is to predict values of ...
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43 views

How do I calculate the confidence interval of an ICC?

Here's the output from my the summary of lmer function which I used to calculate the ICC. ...
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11 views

Active Arm vs Control Arm during ICC

I have 25 factors in my active arm and 15 factors in my control arm. While calculating the ICC should I split the dataset into two, 1) those containing only active arm and 2) containing only control ...
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19 views

statistical analysis of cell culture data

I would be grateful for some advice regarding the optimal approach to hypothesis testing in the following scenario: We have data from a cell culture experiment obtained as follows: We culture some ...
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13 views

How to test assumptions for Intra Class Correlation coefficients?

I want to calculate inter-rater reliability using Shrout & Fleiss' Model 2 (intra class correlation). The general model is: The authors mention different assumptions such as normally ...
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86 views

Could the intraclass correlation coefficient be negative? [duplicate]

I'm a little confused regarding the intraclass correlation coefficient I am now reading "Face to Face interviews " by loosveldt 2008 . He pointed out on page 218 that the intraclass correlation ...
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49 views

Standardization for correlated observations

I am interested in a paper by John Walsh (1947), which demonstrates the effect of intraclass correlation on significance testing. The full text is available here. In outlining a proof, Walsh states ...
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46 views

ICC in a multi level model with two random effects

My understanding is that intraclass correlation gives you an idea of how much variance your level two factor can explain in overall variance of the dependent variable. It is supposed to give an ...
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15 views

Intraclass correlation (reliability) for accelerometer data

I want to assess the reliability of accelerometer measurements for three days. For the calculation of the reliability I use a random-effect model (in R) to get the proportion of subject variance to ...
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25 views

Intraclass Correlation Coefficient for Ordinal Probit model with heterogenous variances

I have a hierarchical ordinal probit model (subjects within locations) with heterogeneous variances, modelled in JAGS, somewhat similar to: http://www.ncbi.nlm.nih.gov/pubmed/19520453. The model is a ...
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13 views

What is the effect of correlated data on hypothesis testing with a linear mixed model?

In 1987, Scariano & Davenport cautioned that non-independence of data had marked effects on hypothesis testing with an ANOVA model (Stephen M. Scariano and James M. Davenport The Effects of ...
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89 views

inter-(-intra) class correlation coefficient or intra-(inter-) concordance coefficient in python

My question is about how to calculate inter-(intra-) class correlation coefficient (ICC) or intra-(inter-) concordance coefficient (CCC), ideally in python. My dataset consists of several dozen ...
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41 views

Intraclass Correlation Coefficient (ICC) between null and full mixed effects model?

I have some questions according interpretation and comparison of the ICC between the null and full model of a binary logistic multi level model (fitted with the R-package ...
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101 views

How to compute intraclass correlation (ICC) for THREE-level negative binomial hierarchical model?

I'm using lme4 in R, and I have a model set up that uses a three-level hierarchy for a negative binomial regression. There is previously a question (How compute the Intra-Class Correlation for a ...
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66 views

Intraclass correlation with count data

I want to calculate the ICC between 3 different measurements where the dependent variable is a count. As far as I understood, if the data were normally distributed, I would use a repeated measures ...
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14 views

Growth in lme nonnested factors

In an experiment, subjects have been assigned to groups and groups have been assigned to experimental conditions (one factor with two levels). The subjects have been measured on a variable 4 times ...
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10 views

Rubric Interrater reliability study

I'm looking at the interrater reliability of a 6-criteria grading rubric used by an online college for graduate students. I have 10 mini-studies with all four professors grading the papers of 12 ...
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9 views

Evaluating the internal consistancy of multivariate judges

Consider the wine judging example: A competition is being run, where There are a number different types of wine, eg Chardonnay, Merlot, Shiraz etc. About 50 types of wine. for any particular class ...
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1answer
210 views

How compute the Intra-Class Correlation for a Negative Binomial Mixed Model in lme4

I have a negative binomial mixed model with counties nested within states. I've read that the formula for the ICC for a negative binomial model is: found here: ...
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22 views

Correct approach for computing interrater reliability

everybody. Can't find a strong answer to this "special case" elsewhere on the interwebs, so I'm hoping you can help. I want to computer interrater agreement (actually, in this case, inter-method ...
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94 views

Notation of Variance of Residuals in Multilevel Modeling

I am having some trouble to understand the notation of variance of residuals in multilevel modeling . In this paper "Sufficient Sample Sizes for Multilevel Modeling" , in p.87 below equation (3) , ...
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90 views

acceptable ICC for 6-point Likert scale

I have pairs of pictures of participants making facial expressions (240 pairs per participant, 11 participants). Two raters agreed on a criterion and rated each one of the pairs on a scale from 1 to ...
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100 views

Calculating ICC using random intercept and residual variances

I have seen many posts refer to the calculation of the ICC by utilizing the variance of the random intercept and the residual variance from a multilevel model. Does anyone have this formula handy?
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126 views

Interpretation of random-effects GLS regression (multilevel model, 2 levels, strictly hierarchical)

There are several values in this analysis that I wonder how to interpret, and whether they can be used to calculate some sort of effect size. Contextual information: level 1 trials in a test - level ...
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18 views

How do you show adequate inter-rater agreement?

I have data from 230 individuals from different companies, who rated their perceptions of their individual companies' organizational climates (four different scales ranging from 7 questions to 4 ...
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82 views

Intra-class correlation and ANOVA for multi-class classification?

I have trained and evaluated with leave-one-out cross-validation classifiers (SVM, logistic regression, deep belief network, gaussian naive bayes, k-nearest neighbour) on my dataset. My dataset ...
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20 views

ICC using one-way random model

I need to compute the ICC value on my data set. I have a set of videos rated by different raters; each rater rated 4 videos randomly chosen. So, I would like compute ICC by using one-way random model ...
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66 views

The valid variance components to include in a generalizability theory model (anova) involving nesting? Are these correct interactions?

My question is about generalizability theory. A study by Bergeron, Floyd, McCormack, and Farmer (2008) is only adding to this confusion. Basically, in G-theory you want the first model you run to ...
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112 views

Intraclass Correlations ICC1, ICC2, ICC3?

I am doing some research for my teacher training. I am looking at the agreement between student-assessment and teacher-assessment. Essentially there are 4 tasks. Students scored the task and I ...
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160 views

Interpreting summary of ICC results in R package “psych”

I have a dataframe "all.st.icc", where 27 subjects have measures of social behavior for each of 8 different years. First four rows of data are as follows: ...
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322 views

ICC interpretation: low/moderate/high

Correlation coefficients and effect sizes often have 'rules of thumb' on how to interpret their values. These guidelines (see for example http://imaging.mrc-cbu.cam.ac.uk/statswiki/FAQ/effectSize) ...
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38 views

Help: testing repeatability within a group, and conducting a PCA for observations within those perhaps-repeatable variables?

I'm trying to analyze behavioral observations of nesting birds within and across various field sites. I know that certain behaviors, such as latency to flight, amount of vocalizations, and defensive ...
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35 views

Two separate or a single mixed-effects model?

Lets say my data is exam results of students nested in schools and there are two kinds of schools: private and public ones. Now, what I am interested is the variance between private and public ...
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273 views

Intraclass Correlation Coefficient value range vs strength of association

I read on this site that ICC is a good measure of association(effect size) between nominal and interval data..and the significance test suggested was anova...My question is, given the association is ...
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150 views

within group agreement, intra-class correlation, one way ANOVA to justify data aggregation

I am working on my research involving aggregating individual data into group data. Predictor: Task conflict (3-item scale) Process conflict (3-item scale) ...
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179 views

Which Intraclass Correlation Coefficient for Repeated Measures by a Single Rater

I have a set of measurements (up to 4 per patient, with some missing values) made on 500 patients made by the same physician (a simple example is given below). ...
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613 views

sample size for test-retest reliability

I am interested in estimating the following: test-retest reliability for ordinal items; test-retest reliability for interval-level scale scores consisting of the items; and the optimal sample size ...
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26 views

interrater reliability for proportional (not count) data

My experiment has the following form: a rater assesses a visual image and records a single value, p, which is his estimate of the proportion of that image composed of a single color. Thus, the data ...
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53 views

ICC for growth model

I have searched quite a bit for this answer. Is there an ICC for unconditional growth models. Not the unconditional means model, but a growth model. I suppose I mean to ask is there a way to describe ...
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32 views

Observer agreement in multilevel binary data

I have a set of participants indicating with drawn circles where they experience pain on a manikin of the human body. These drawings were then independently rated by two human raters: each of 29 body ...
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60 views

Panel data: Compare two different assessment methods

Just wondering if anyone has any inventive (but relatively simple) ideas about how to approach comparing panel data from two different assessment methods that collect the same variables. Basically, I ...
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87 views

Intraclass correlation and simulating data

I will apologize in advance for this somewhat messy problem. I am trying to take an ICC reported from a previously published manuscript and design a general simulation program. Let's say the ...
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968 views

Interpretation of variance in multilevel logistic regression

Please help me to interpret the findings of my model. The specifications of the model are: Dependent variable: treatment (1) or no-treatment (0). Independent variables: age, number of drugs used, ...
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89 views

$R^2$ for mixed models = ICC?

I will be referring here to Nakagawa and Schielzeth (2013). As those authors state, $R^2$ for OLS regression could be defined as follows: $$R^2 = \frac{\sum^n_{i=1}(\bar{y} - ...
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782 views

Acceptable values for the intraclass correlation coefficient (empty model)

I'm using xtmixed in Stata to test a Hierarchical Linear Model. My problem is that variance at level 2 is about 4% of the total variance. So most of the variance is ...