Questions tagged [group-differences]

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

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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 ...
22 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 ...
23 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 ...
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 ...
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 ...
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 ...
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 ...
49 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 ...
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 ...
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 ...
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 ...
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-...
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, ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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. ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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: ...
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 ...
28 views

Group comparison for extreme value data: which method is suitable?

I have measured Gaussian curvature data of 3D objects from two different groups, A and B. I would like to find out whether the objects differ in curvature. The distribution of data values for each ...
32 views

How can I compare how significant is the difference between three or more distributions of count data?

I am researching whether software developers use different numbers of communication channels when performing different activities. Therefore, I would like to know whether, depending on the activity, ...
30 views

The difference between means in t-test

When the sample size is large, the results tend to be statistically significant even when there is a small difference between the means of two groups. however, sometimes we see the results are not ...
16 views

Group comparison for bivariate distributions

For two groups A and B that consist of n and m individual samples. Each individual sample has a unique 2-dimensional joint probability density functions (PDFs)of two variables. These PDFs are ...
7 views

Test for difference from 0 for non-normal distribution

I'm using an agent based model to study disease transmission. After the initial outbreak, percentage of population infected decreases to zero. I'm looking for a rigorous way to choose when the % ...
10 views

Comparison of two groups of time-series

I have time series data collected from two sensors. Suppose that they are microphone recordings from a man and a woman. Each signal, e.g. the one below, is 5000 samples. They don't share some ...
86 views

Mixed models. Random slopes only, mean and group centering?

Are random intercepts a theoretical/practical prerequisite to random slopes? Why? I have a three level (rep measures) mixed model where I wouldn't expect lvl 3 variation in initial status of outcome ...
11 views

Real (not rounded) Lower and Upper limits of groups of frequency distribution and Median for infinitely continuous data

From here on page 5: https://www.pbarrett.net/techpapers/percentiles.pdf So how can both be correct – yet seem to be more appropriate under different conditions? The clue is spread throughout the ...
53 views

Whether there is significant difference between the slopes of different gender groups

The last question I have posted here: Whether there is significant difference between two gender groups There are 16 people in the dataset(using subjectID to ...
12 views

Test that predicts group membership from multi-variate data?

Context: Zoology undergrad dissertation. The format of my results will be % time individual birds spent doing certain activities (and possibly number of times an activity such as pecking was performed)...
39 views

Whether there is significant difference between two gender groups

A data set contains 5 columns: There are 16 people in the dataset(using subjectID to identify them). Each year, when these people were ages 11, 12, 13, 14, and 15, they provided us a score $y$. We ...
28 views

Standardized Difference to compare prevalence between 4 groups

In this article, https://www.tandfonline.com/doi/abs/10.1080/03610910902859574 Peter Austin describes how to calculate the standardized difference between two groups, pg 1229 and pg 1230. However am ...
11 views

Effect size on the difference between group differences (ΔA-B vs ΔA-C) using R

I am trying to calculate effect sizes, but all I can find on the web relates only to the effect size of the difference between two groups. What I am interested in, is the effect size of the difference ...
134 views

Male-female height difference estimation from thresholds

Introduction. Assume that two populations $A$ and $B$ are distributed with normal distributions $N(\mu_A, \sigma_A^2)$ and $N(\mu_B, \sigma_B^2)$. This is a general problem, but as an example, I will ...
15 views

Estimation of substitution effect

I have a market with three goods: PRODUCT_I,PRODUCT_II, PRODUCT_III. PRODUCT_I is banned by a policy, and its sales brought down to 0. I want to estimate to what extent PRODUCT_II and/or PRODUCT_III ...
63 views

How to estimate the confidence interval of the difference of means?

I have two sets of measurements (repeated measurements of two processes, let's call them $X=\{X_i\}_{0...n}$ and $Y=\{Y_i\}_{0...m}$), and I would like to estimate (with confidence interval) the ...
70 views

Grouped data as independent variable for continuous outcome

I have an independent variable grouped into irregularly sized classes (0, 1-5, 6-10, 11-20, >20), a continuous dependent variable, and several control variables. So far I've been trying to stay close ...
19 views

Which Test should i run to check if there is any difference between variables?

I am analyzing one data set that contains 200 observations and contains information about two types or murders. It has 49 variables and I am interested in checking whether there is any difference ...