Questions tagged [group-differences]

Group differences broadly refer to statistics which quantify the differences between two or more subpopulations.

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45 views

Is two group comparison test combinig rarefaction and permutation usefull and correct?

I wish to know if the analytical procedure using R environment described below is statistically coherent to enable interpretations and conclusions. I looking for evaluations and opinions about the ...
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2answers
64 views

Compare which of two groups is MORE similar to a third group?

I know I can use an ANOVA (+ post-hoc tests) to determine the equality (or inequality) of three groups: (i.e., H0: each of 3 means are equal; H A: at least 1 of 3 means is not equal). However, how ...
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248 views

Testing difference in proportions with bootstrap

Summary: I want to perform a bootstrap test on the difference of proportions. I think this is equivalent to testing the difference between means using bootstrap, but I wanted to clarify some details. ...
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1answer
230 views

T-test with nested data

I want to test gender differences in an outcome variable called the willingness to pay. My data consists of records with following three fields: ...
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1answer
28 views

Determining best cutoff value between 2 groups

I have 2 groups (say G1 and G2) and there is a continuous variable (say V) which is significantly different between 2 groups. The mean values for 2 groups are m1 and m2. I want to determine what is ...
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21 views

Proportion test: one sample or two sample?

We introduced a new way of teaching children this summer. We then split the children (As randomly as possible) into 2 groups. Group 1 children were taught in the new style, Group 2 children were ...
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22 views

bayesian estimation of difference between 2 non-normal groups

Lets say we have 2 sets of groups with random variable X as shown. Features of X based on real dataset: They are all positive numbers have really long right tail and almost no left tail Cant share ...
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1answer
203 views

Is it valid to do a mixed ANOVA with one within and one between subjects factor when the between subjects grouping factor has very unequal groups?

I am doing a mixed ANOVA in SPSS where I am currently comparing the duration of certain script handwriting in 2 conditions (1=eyes open and 2=eyes closed) for the same 40 participants in both ...
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13 views

Compare responses of two groups of their responses to how they rate their preference

Two groups of respondents where asked to rate their concern on 1-10 Likert scale (which effectively means ranked responses). In effect, for each groups, I have a number of respondents who ranked their ...
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1answer
389 views

Statistical differences between two hourly patterns

I have 2 groups of subjects, namely: Subjects that are younger than 67 Subjects that are older than 67 Each subject of each group wears a sensor that estimate the metabolic equivalent of tasks (METs)...
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3answers
42 views

Testing for statistically significant difference between two groups: Frequentist vs Bayesian

When testing for differences between two groups or samples, what is the best approach in concluding statistical significance? The orthodox approach is to take a t-test or an Anova when there is more ...
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58 views

How high variance effects differential gene expression analysis

I was wondering if anyone had any advice on comparing two groups where the variance in once group is high and the variance in the other group is low. Specifically, I am attempting differential gene ...
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1answer
542 views

Difference between regression between groups vs across all subjects (continuum)?

I'd like to understand this better in terms of drawbacks and suitability. For example, if my data includes investigating differences between 2 patient groups and a control group (3 groups in total), ...
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1answer
38 views

Significance of differences between group-differences

Background: We have RNA-seq data (a method to quantify the expression of genes in a cell) from different cell types. These data were normalized using a method called TMM and then log2-transformed ...
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612 views

Comparing bins (quintiles, deciles) based of $R^2$s from multivariate regression

I have a multivariate linear model: $\mathbf{Y} = \mathbf{X}\mathbf{B} + \mathbf{U}$ where the matrix $\mathbf{Y}$ represents stock returns, the design matrix is constituted by some explanatory ...
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1answer
157 views

How to compare distributions of two groups where each group has multiple observations from a small group?

I have data on continuous measurements (length of time of a behaviour) from two groups of individuals which differ in their phenotype (phenotype A or B, the variable used to group them). Each group is ...
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568 views

Two-sample bootstrap?

I have two independent samples of observations. From each sample I produce a statistic. Let's denote these as $\theta_1$ and $\theta_2$. I'd like to test the hypothesis that $H_0: \Theta_1=\Theta_2$, ...
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13 views

How can you test which groups are in different distributions? [closed]

Let's say I have a some grouped data and I want to tell not only if the groups are all from the same distribution or not, but I also want to tell which groups are part of which distributions. ANOVAs ...
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1answer
19 views

Hypothesis test for the difference of two means, should I consider annualized or monthly returns?

I have 10 years monthly returns. I calculated annualized return multiplying the mean return over the period for 12. Then I calculated the excess returns as difference between the annualized mean ...
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1answer
577 views

Principal component analysis with non-independent observation

I have observations with 6 individual-level characteristics from 2000 units in 56 groups (villages). I know that within groups, characteristics are strongly related as individuals influence each other....
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12 views

equivalence testing

I'm looking into a data-set with 3 experiments. From experiment 1 I do have 11 samples and for the other two experiments i only have 2 samples (with an high error). I would like to know whether the ...
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1answer
232 views

Different results doing mixed effects anova and post hoc tests of simple effects and paired T-test

I have run a mixed effects anova in r to look at the performance differences in two groups (control, patient) in 5 separate conditions. The conditions are my within subject factors. Group is the ...
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36 views

Comparing means between two groups with Chi square distribution

Model fit to covariance matrix produces a chi square measure and associated degrees of freedom. In a Monte Carlo study I have two differently generated replications, say Group 1 and Group 2, and the ...
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0answers
18 views

How to detect calendar effects for stock prices (day-of-week, month, etc.)

This is a python/pandas question just as much as it is a statistical one. How would I go about determining the typical delta for day-of-week and month effects of a given time series? Taking the day-...
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1answer
30 views

Comparing the difference between two mean differences (x1 - y1) vs. (x1 - y2)?

Could I get advice on what statistical test is most appropriate assuming the data conform to assumptions made when running parametric tests. I have conducted a study with 4 conditions (one control, ...
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1answer
154 views

How to measure the effect of users' participation in forums?

My problem is how to measure the effect of a user's participation in forums. I calculate the user's participation as the number of discussions that user posted. My hypothesis that a users' ...
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4answers
1k views

Grouping samples by clustering or PCA

If I have 5 binary variables with values for 100 observations to give me a 5x100 matrix. ...
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1answer
17 views

Group comparison for small sample with repeated measured data

I have very small dataset. When I conducted rank sum test between the groups (A vs B; A vs C), I found no significant results, but just trends level difference. Is there any alternative statistical ...
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2answers
18 views

Difference between two groups of people, each person “is” several characteristics

I have two groups of people, A and B (let's say 15 and 25 people). Each person in each group is characterized by a bucket of features (bucket = 6-18 features). Each feature, during qualitative phase ...
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1answer
161 views

Comparing sets of noisy discontinuous curves / histograms

I have a dataset composed of measurements of signal intensity along a line; visually they look roughly like the right half of this: Each sample is a discontinuous "curve" composed of roughly 600 ...
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1answer
206 views

ANOVA (assuming different distributions) vs Kruskall-Wallis and post-hoc tests

During stats courses on Uni I learnt (if I remember correctly and hopefully don't put my teachers to shame) that if you want to compare multiple groups with eachother you look at the residuals of an ...
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3answers
1k views

How to compare ranked data?

I have some questions about how to analyze ranked data. The data looks like this: 4 groups of people with HIV and 16 other groups of people living in the same village were asked to rank 12 ...
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3answers
7k views

Comparison of ranked lists

Suppose that two groups, comprising $n_1$ and $n_2$ each rank a set of 25 items from most to least important. What are the best ways to compare these rankings? Clearly, it is possible to do 25 Mann-...
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22 views

How to interpret the difference in topic proportion (theta / document-topic-probability) of two groups?

I am comparing the difference in mean topic proportion (theta / document-topic-probability) of two groups. How can I interpret whether the differences are small or large, as topic proportions depend ...
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23 views

What is this specific statistical approach/term called?

I need help in identifying the underlining statistical term of my method (deviation of group membership of a Person to an ideal role) So I have Ideal values (for the ideal role) shown here in the 1st ...
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210 views

How to find groups in data, characterized by the most different behavior in alcohol consumption?

I've got a question concerning the Student Alcohol Consumption dataset from the UCI Repository. Please, help me understand which methods or models, preferably using Python and sklearn , to use to ...
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1answer
40 views

Statistically comparing 3 groups - Test for statistical difference [duplicate]

I will like to perform and statistical comparison between 3 groups, in order to determine if statistically they are different or not. My data for all of the 3 groups follows a normal distribution. I ...
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0answers
23 views

Statistical test for significance on difference in scoring values on ordinal scale between two groups

Statistical test for significance of the difference in scoring values on an ordinal scale between two groups. Respondents were asked how worried they are about something on a scale between 1 (least ...
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1answer
263 views

How to quantify the similarity/difference between groups of selected features?

Since I have a imbalanced data to deal with, I randomly down-sample the negative data to reach balanced data for following feature selection and classification. To test feature's robustness to ...
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1answer
48 views

Comparing heteroscedastic groups with sample sizes from 1 to 24… No valid tests?

I'm comparing 1 continuous variable across 36 groups (nurses grouped into 36 hospital units). Several groups have only 1 observation, but most have more, ranging from 1-24 observations per group. ...
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1answer
26 views

Single Group Pre-Post McNemar Table Set Up

I am looking to evaluate if the change in proportion for a group changed pre-to-post intervention. Essentially, is the ~7% increase from pre (~2%) to post (~9%) significant. I am running the McNemar ...
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12 views

Repeated measures with rotation of subjects within groups

I was wondering if you could help with the interpretation of a potential experimental design. We are testing two versions of a 'group' exam, score (out of 100) being the outcome variable, aggregated ...
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1answer
463 views

Comparing multiple likert items across two groups - is the MANOVA appropriate?

I would love to compare 9 multinomial (4 point likert) and 2 binomial (yes/no) measures across two independent groups but I am not sure what test is most appropriate. Treating the group as the ...
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0answers
17 views

statistical significance of difference between shares

I am trying to conduct a statistical test of the difference between two shares expressed in percentage points. While I could use a regular t test if the difference was between two means, with shares I ...
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0answers
11 views

How to know if there is a difference between two populations or if some feature has influence on a certain response variable Y?

I have a database about claims at auto insurance. I can do the math and get Frequency, Severity, Sinistrality. I need to know if cars with automatic transmission have a higher propensity to accidents ...
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8 views

Obtaining Mean Differences from DESeq2 Output

I have conducted some analyses using DESeq2 and obtained the output. However, instead of interpreting the effect sizes as log2FoldChanges, we would prefer to obtain a model-based mean difference. I ...
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0answers
16 views

Testing if number of observations in experimental conditions is statisically different

I was conducting in experiment in which i sold products on a pay-what-you-want basis in 4 different information conditions. Apart from comparing the average willingness to pay across the 4 different ...
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53 views

Statistical test for dependent data- comparing groups of pairs

I have a question about statistical tests for dependent data. This will sound a bit strange/extremely naive but pls bear with me- here is my problem formulation: I have 500 individuals, and I'm ...
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1answer
51 views

Testing whether the means within group are different from each other (R)

My Y variable is binary and takes the values 0 and 1. The same applies for the independent variable X. I've been able to create the means within the group, here: ...
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11 views

Test difference of means between subgroups

I have a collection of N samples from which I have computed all pairwise Euclidean distances. The samples can be divided in 3 distinct subgroups. I want to test if the average distance of groups is ...