# Questions tagged [coefficient-of-variation]

A measure of dispersion expressed relative to the mean, used for positive variables. Equals the standard deviation divided by the mean.

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### Comparison of dispersion measures of different samples with different subsamples

Context: I have data on movie ratings and I want to find what factors affect the rating the most. I have $k$ features $F_1, F_2,\ldots,F_k$ characterizing a movie - for example, director, lead actor, ...
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### The coefficient of variation as a measure of “narrowness” of a distribution

In this lecture about statistical mechanics, page $10$, the author said that for a peaked distribution, like the one below, the width of the peak is proportional to $\frac{\sigma}{\mu}$, where $\mu$ (...
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### Calculating calm market [closed]

I want to find when the market is calm. By calm I mean that it shouldn't go up or down. Instead, it should stay inline or close to inline. For this reason, I'm trying to calculate the standard ...
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### Calculating the coefficient of variation within pairs

I would like to calculate the coefficient of variation of an assay where I measured each sample in duplicate. I have no statistical background but from my understanding I would need the standard ...
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### Repeatability and Reproducibility Coefficients of Variation

I sometimes see in papers report Repeatability CVs% and Reproducibility CV%. Sometimes its described as within-group CV% and between-group CV%. But in papers I've seen these calculated multiple ...
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### Test for Statistical Differences Among Coefficients of Variation (using R)?

I have two datasets, and I wish to determine the statistical difference between two groups. I am comparing a visual plant injury scoring system to a remotely-sensed scale, and the coefficient of ...
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### coefficient of variation and genes highly expressed

I am a biologist, with very little knowledges of statistics. I am looking for highly variable genes from a data set. I have calculated the coefficient of variation of the expressed genes of my dataset ...
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### Gamma GLMM Dispersion, Random Effects, and CoV (lme4)

So I know that in glm(), with the Gamma family, one can get the dispersion parameter through the MASS package with gamma.dispersion() or can even look at the summary output as a quick estimate. How ...
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### Total sum of squares or coefficient of variation

I have two sets of histology data for the same set of patients, each with two samples. Both are made based on fraction stained cells relative to total number of cells (stained+unstained), but their ...
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### R-squared and sample size

I was wondering if R-squared is affected by the sample size? Is adjusted R-squared also affected? The reason behind this though is, that i have run a multiple linear regression on two samples. The R^...
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### Standard Deviation (SD) vs. Coefficient of Variation (CV)

Which of the following two data sets is more dispersed? Assume that both data sets are normally distributed. Data Set A: $\mu_A = 1$, $\sigma_A = 1$. Data Set B: $\mu_B = 10$, $\sigma_B = 1$. ...
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### What's the best method to measure relative variability for non normal data?

I have a set of data that states the volume required each month for the next 12 for 750 raw materials. I would like to determine the variability in the demand for each material, and categorise the ...
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### Methods to quantity the applicability of an regression to a larger population

Simple question I believe, but I am not as sharp on my stats as i would like to be. I have 66 items with a calculated value associated with them, due to data restraints I was only able to find a "...
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### Comparing standard deviation with coefficient of variation

I have series A that is daily levels of a stock index, from which I calculate daily returns, then calculate the std dev of the daily returns, and multiply by (250)^0.5 to get annual std dev of returns ...
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### How should I compare variability across repeated measures in a single trial vs variability across measurements across repeated trials?

I have collected some data from different subjects in 2 different ways. In the first way, each subject performed one long trial, I segmented the data captured and and calculated a variable value for ...
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### Coefficient of variation of correlation values

I have the following problem that I am not sure of whether I treat it correctly: I run repeated simulations, where the output of a single simulation replicate is a single correlation value. The ...
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### Standard Error over the mean: a valid 'modified coefficient of variation'?

At my work, we have used a 'modified Coefficient of Variation', defined as the Standard Error over the mean, and I wanted to ask if there is any statistical justification for this. We are interested ...
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### Coefficient of variation and residual standard deviation

From my knowledge, coefficient of variation and residual standard deviation are highly correlated. Such that if we find a significant change in one, we will find a significant change in the other. In ...
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### is coefficient of variation better measure of highly variable features?

I am trying find highly variable features (genes in my data) for downward consensus clustering analysis. I have used variation, median absolute deviation and coefficient of variation (CV) for finding ...
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### ANOVA on time series Data

I’ve been dealing with this problem for quite a time. I’m running an experiment with plants growing them with Compost A and Compost B. I’ve been measuring the pH each day at the same time and keeping ...
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### dependency of the deviation to the measurement level: how to test normality?

A machine measures the height of some plants. In the context of industrial quality procedures, we repeat the same measurement Hi 10 times and expect the ...
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### How to compare two distribution where each point is not from a independent sample

columns are samples and rows are genes. There are two groups. I calculated coefficient of variance (CV) for each group so for each gene there are two CV one for group A and one for group B. I ...
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### What does the author mean by “scaled version” of standard deviation?

I was trying to understand how to use XYZ analysis when I came upon this article. The author says that using coefficient of variation of an item (which is a ratio of standard deviation and average ...
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### Coefficient of variation values?

I'm doing an assignment on which I'm analyzing a data sample of roughly 1400 soccer players from Europe and I'm not sure how to interpret the coefficient of variation, to be honest. For instance, ...
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### How to compare annotations by two groups?

I have two groups of test persons that manually created multiple annotations for different underlying, unknown values (each person created multiple annotations). I'd like to find a statistical test ...
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### Comparing variability of measures across time

I am working with some data where I have measurements for two outputs (Output A and Output B) for 5 participants in an experiment. Each of the 5 participants have both their Output A and Output B ...
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### Can we use a coefficient of variation as a statistic for testing homogeneity of variance?

There are well-known HOV tests, for example Levene's, Brown-Forsythe's, Bartlett's available in SAS and R. But $C_v$ also deals with dispersion, can we use it to understand the degree of HOV? July ...
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### Coefficient of Variation across Prediction Intervals

I've run into an odd problem that I have a simple answer to but would like to know if there's something deeper to it. I have a data set with 7 observations, each with 2 variables (X,Y). I then run a ...