Questions tagged [variability]
Variability or dispersion describes how a variable's values are spread out or compressed.
Measuring intra-observer correlation
We're far from what you'd call expert statisticians, so we'd like to ask some help in an ongoing medical research. We have 60 subjects. A researcher took at least 3 times the measurements of 8 of ...
Estimating if a distribution is significantly less conserved than others when one group is involved.
I am looking at levels of genes in a dataset and want to identify genes that do not vary much in terms of their expression level. While I can do this using the coefficient of correlation, calculating ...
What exactly is the "proportion of variability explained"?
One often hears to say "more than 70% variability is explained by ..." What exactly is meant by this? Th proportion of the sum of squares (SSE), or mean sum of squares (MSE)? For example in the ...
The search for statistical dispersion before tests… and multiple testing issues
After finishing a data collection season, there's a huge dataset containing n>>1 variables (columns) and a few different observations divided by group (rows; let's say cases and controls). The task is ...
Measuring relative variability for variables with different scales
I want to compare the relative variability of several sleep-related variables in the same group of subjects. For example, is there more variability in time spent in REM sleep compared to the number of ...
Help needed in computing Inter-rater, intra-rater variability
I have been working on a test in which I need to quantify the variability in a process. The process in question involves positioning a number of landmarks on an anatomy. There are two sets of ...
Looking for significant variability of categorical data in columns of data frame
I have a data frame with each column contains categorical data: 0,0.5,1,-1 ...
Measuring inter-subject agreement in user ratings
In my system I have users rating objects (e.g. films) from 1 to 5 stars. The mean rating clearly tells something about the overall opinion on an object, but I'd like to use a more precise measure of ...
How to compare the variability of two measures from meta analysis?
I have two measures from each of 20 studies. Random-effects meta analysis has been performed for each of the two measures, and for each measure I have two values to indicate data variability, cross-...
Inter-experimental variation in survival experiment - how to estimate variability?
In my animal experiments, I do survival studies, which generate Kaplan-Meier survival curves for each group, which I then compare with an appropriate log rank test. My question is: If I have run a ...
How do I compare the repeatability of two sets of experiments with a low number of samples?
I'm investgating the repeatability of an experimental process (actually measuring lift in a wind tunnel), which can be measured using a single number, Q. However, I only have limited access to the ...
Estimating variability over time
I have a dataset that contains ~7,500 blood tests from ~2,500 individuals. I'm trying to find out if variability in the blood tests increases or decreases with the time between two tests. For ...