Questions tagged [group-differences]
Group differences broadly refer to statistics which quantify the differences between two or more subpopulations.
676 questions
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Group comparison (and pairwise tests) with non-independent data
I'm trying to determine if there are significant differences between groups and identify which groups differ from each other.
First, let me explain the experimental design:
I have 6 Locations. Inside ...
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Sampling observations from nested groups before ECDF and KS testing
I am creating and comparing ECDFs of percent cover value (0-100%) for three groups of biological observations.
The dataset as a whole is large, with over a million observations. The three groups have ...
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Is Cochran's Q test appropriate for comparing a few VLMs on a dataset with more than one question per image?
I have a dataset of N images, k questions per image, Y/N answer for each question. I want to compare the accuracy of m VLMs (Vision Language Models) over this dataset: these are models, similar to the ...
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Alternatives to odds ratio (OR) when non-independent observations
I'm working on a medical research project where our main dataset consists of presentations to the hospital over a long period. During this time, a significant number of patients present multiple times,...
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Circular statistics for comparing groups with repeated measures in R
I have 3 uneven groups. Each subject has 5 to 15 observations.
My data is circular (0 = 1), and ranges from 0 to 1. I want to compare both the group means, and the dispersion.
In a linear model, my ...
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Can I use baseline averages of mediators for controls in a Difference-in-Differences (DiD) analysis?
I'm attempting to estimate the impact of the Belt and Road Initiative on inflation using staggered DiD. I've been able to get parallel trends to be met using controls unaffected by the initiative but ...
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Determining if sample is composed of two groups
Say that I have a dataset where each row consists of a test score scores and a test preparation level. The scores are integer numbers ranging from 0 to 100, inclusive, and the test preparation level ...
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Which statistics or statistical procedures would show the effects of different types of physical exercises on some hormones?
I am an academician and had an experimental study on the effects of different types of physical exercises on some hormones. I set up three groups: high intensity exercise, low intensity exercise, and ...
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Poor reliability for difference scores in behavioural tasks: implications for ANCOVA, LMM where the raw RT data is used in analysis
I have measured RT in two conditions: condition A and condition B and I am interested in how RT in these conditions interacts with anxiety score. As is common, the split-half reliability is excellent ...
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Testing discrete variable on paired data (R implemented test)
I have paired data representing blood pressure measurements taken before and after treatment for each subject.
The after-treatment value depends on the type of treatment (three types: trt1, trt2, and ...
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How to compare two components' reliability?
I have two different components in service, an old one and a new one. I want to know if the new component is more reliable than the old one (ie: higher MTBF)
Group1 Old component: contains 80% of the ...
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Unsure what stats test to use for my data: ANOVA or chi-square
I have a matrix of 17 features by 9 groups with the values being the counts for each feature appearing in that group, eg:
Grp1
Grp2
Grp3
Grp4
Grp5
Grp6
Grp7
Grp8
Grp9
F1
2
9
0
1
0
0
1
2
0
F2
3
4
0
0
0
...
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How to retrieve main group effects from GEE in R (anova?)
I want to know if the outcome variable differs across three groups. As my data includes several family members, I use a Generalized estimating equations (GEE) model in R:
...
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Why is a pooled mean necessary in bootstrapping the difference in means?
Formulated Question
In a two-sample bootstrap procedure for testing the difference in means, why is it insufficient to subtract the group-specific mean from each bootstrapped observation (centering ...
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Unsure as to what tests, how, and potential in a research scenario
There are three classrooms of students of different grades. I want to analyze what variables of these influenced likelihood of scoring 0 on a test. The factors are: grade (8, 9 or 10) and stress level ...