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Questions tagged [group-differences]

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

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Is this a matched pairs data set?

A review problem for one of my daughter's statistics classes: The arm span and height of 10 individuals is measured in order to test the hypothesis that arm-span equals height in humans. Perform an ...
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1answer
39 views

How do you test if three means significantly differ from each other using an F test?

I know the means, sample sizes, and standard deviations of three samples drawn independently from three populations. I need to test whether they differ significantly from each other using an $F$ ...
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Survey subgroup difference from entire survey or excluding the subgroup?

I have a survey with categorical (nominal) questions. I want to compare subgroups to see if any are noticeably different from each other. Suppose they are ranking their preferred three from ten ...
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13 views

Comparing statistics over win/loss

I have data from a league over a season. The season was conducted as a round robin so everyone played each other. Each game was a best of 5 so at the least a game produced 3 matches and at the most ...
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0answers
34 views

Significance test of procentage number with unknown variance?

Can anyone help me clarify if its possible to do significance test given the data below? I want to calculate if the procentage of people who remember having seen a video is significantly higher for ...
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0answers
9 views

Porbability of an observation to belong to a specific group

I have a group with about 200 observations,and each observation has 2 variables (which are the first two components of PLS, if it matters). It looks like this: ...
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16 views

Find significantly differences between multi-variant groups

I have 11 groups, each consist of about 200 observations, and each observation has 2 variables (which are actually the first two PLS components if it makes any difference). Each group is a substance ...
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1answer
28 views

analyzing difference between two groups by other numeric factor with only (0-5) values

I want to analyze the difference between two groups by other factor. the factor is numeric with distribution (0-5) only. using Stata® what would be the best test to estimate the significance of ...
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30 views

Weibull coefficients comparison [closed]

I´ve 838 sets of data that represents points distributed by height. Those that can be fitted by Weibull function. So, I normalized them and adjusted the corresponding distribution function, saving it´...
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12 views

Comparing rates in groups with different sample sizes

I have about 20 different geographical areas, in each of them I have people that signed up to receive a daily newsletter. The smallest area has 500 newsletter subscribers, the biggest 30.000. Everyday ...
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1answer
43 views

Differences between exponential distribution with very different n sizes

I need to test for the differences between three groups of observations (grouped along $x$-axis), which appear to follow an exponential distribution along the $y$-axis dimension (see example fig.). ...
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0answers
31 views

Regression Equation to test for Differences in Differences

I am working on a problem, but I am stuck in trying to find the proper term to use in my regression. Basically, here is what I am trying to solve : Say I have a dataset with data from like four or ...
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1answer
28 views

Comparing the results of 2 different type but identical samples from 2 devices

I have 2 columns of of the concentration of fat in fish which is measured by 2 different labs. I need to know if the difference of the results from these 2 labs are statistically significant. The data ...
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1answer
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Sample size for 2 groups vs. one large group to measure spread?

I hope this question can simply be answered conceptually, without a specific dataset. I am planning a new study, for which I will be testing the effects of depression on a memory task. I'm currently ...
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0answers
52 views

Comparing the means of two groups when a large number of data points have the same value

I have data on the profitability of wagers made according to two different strategies. One strategy was to bet $1 on the underdogs in each of a sequence of sporting matches. They have data like this: ...
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0answers
31 views

Time Series sampled at varying frequency - Employ Linear Mixed Model to compare trends?

I hope that this question has not be asked like this elsewhere, if so I could not find it during my google research.. I have the following problem: I have data sampled from different sensors("ID") ...
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0answers
13 views

How to test for difference in weighted proportion difference? (and average weighted proportion differences)

Suppose I have a survey where respondents rate different questions as positive (1), negative (-1), or neutral (0), and their responses are given a different weight based on which job they have and ...
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0answers
20 views

Randomized Treatment within treated group

I don't know if this situation has a particular name. I'll just give the example and my question. Suppose we have two naturally concurring groups, $A$ and $B$. By that, I mean there is a naturalistic ...
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0answers
36 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
35 views

How to apply fixed effects in R?

In this example they just want to know if the announcement decreases the trading assets ratio. What are fixed effect in application here? Meaning of quarter and companies fixed effect? How they keep ...
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0answers
27 views

Which test to use to detect difference in proportion between more than 2 groups? Logistic regression?

I have data that looks like this: there is a group of 27 subjects with one dichotomous variable y1 at 3 times points. The propbability of y1 is different between the 3 time points (100%, 85%, and 40% ...
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0answers
10 views

Compare principal components/differences between two groups

I have four groups of individuals which have a certain illness and are part of a clinical trial: Taking drug, illness gets better Taking drug, illness is not getting better Taking placebo, illness ...
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0answers
44 views

How to statistically model this group difference?

I am studying if men and women consumers differ in how attractive they find product advertisements written differently. I am specifically looking at positive and negative sentiments as two ...
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0answers
57 views

Test if mean of one group is significantly different from means of several other groups [closed]

In my experiment I have a number of clusters of cells from an unsupervised clustering. Each cluster represents a cell type, and can be seen as random samples from a large pool of possible cell types ...
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0answers
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Running analyses with uneven group sizes [duplicate]

I was trying to run a study with 100 people per condition for 4 conditions. When I looked at the results, the group sizes were skewed - some had 80, some had 120. If I'm planning on running a series ...
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0answers
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Hypothesis test on differences in absolute effect size (difference in difference in means) with skewed data

I am comparing highly-correlated ways to classify patients as positive or negative for a disease. I classify patients as positive or negative under disease definitions 1, 2, ... and then look at the ...
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1answer
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Test of difference maximum likelihood parameters SEM R

I have a structural equation model implemented in R 3.4.4 using lavaan 0.6-1 and estimated on two different subgroups using a robust maximum likelihood estimator. Now I want to compare the parameters ...
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0answers
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Group comparison after clustering (without using statistical tests)

I have a dataset whose variables can be grouped in variable sets (VS) 1 and 2. VS1 represents blood parameters, VS2 other phenotypic data. Variables in VS1 are standardized to N(0,1). I have ...
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0answers
22 views

Group comparision in repeated measures data with missing values?

I have data from blood samples collected from 20 patients before, during (at 30 min, 1 h, 2 h, 3 h, 4 h) and after a medical treatment (using the slightly different treatment protocols A and B). The ...
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0answers
25 views

Comparing observed and expected diets of two different species

My data consists of dietary data from two species (C1 and C2) and expected diets for each species (E1, E2) generated from a combination of variables, but is based on their foraging behavior. What I ...
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0answers
13 views

Compare occurrence of events

I have two groups of samples (A = 25 samples and B = 40 samples). In both of these groups can happen a series of events (or a series of groups of events classified as n-grams) that can happen ...
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0answers
42 views

Is log based transform comparable across groups with different minimum values?

I have data for different groups that includes positive, negative, and zero values. Here is an example: group1: c(-503583,-395833,0.1,3835,19,-0.001,0,48400883) group2: c(-39,-8340,-10,0,0.1,2889,93,...
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0answers
40 views

Difference in distribution of multinomial distributions

I have some questions regarding how to analyse catagorical data, summarised as percentages on an individual level. In the data in question, for each individual we know the fraction of biological ...
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0answers
24 views

Combining intra and inter cohort comparison using panel-data

After reading numerous posts, I still haven't found a conclusive answer to my question. I have panel data for the whole population(multiple years, interlinked by personal identification numbers), ...
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0answers
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How to compare the grouped random forest importance across different models?

I have a modeling problem where I have a reasonably large number of features (~75) that can be separated into 3 broad classes. These features correspond to field plots where measurements were taken. ...
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1answer
241 views

Jonckheere-Terpstra test: two-sided and one-sided, directed and undirected hypotheses

I need to perform a Jonckheere-Terpstra test, but I am not sure how to do it and how to interpret the results. I have following data: Three groups doctors1, doctors2, doctors3 And how often they ask ...
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0answers
42 views

Conclusion on which groups differ without doing post-hoc test

If you do a statistical test that compares groups and find a significant difference between groups, can you then conclude that there is a difference between the "lowest" group and the "highest" group, ...
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0answers
20 views

Comparison of unbalanced groups of values

I know there are several questions (here and on other websites) regarding the comparison of values, but I am still lost with the data I have and the analyses I should conduct. I have just 18 values (...
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0answers
28 views

Comparing groups for hypothesis testing

I have the following analysis to do: what is the relationship of age to blood pressure on overall data. Then, examine the relationship in each subgroup. I have blood pressure readings, continues ...
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0answers
16 views

Contingency table for nominal (count data) that is grouped

I'm looking to get my head around analysing some data for a neuroscience experiment I'm running. For the sake of simplicity and ease of communication I'll explain the problem here using pencil cases. ...
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0answers
51 views

How and when to use multiple comparison tests

There seems to be some variability in WHEN multiple comparison tests such as Bonferroni or FDR might be implemented. Type 1: One might carry out multiple one-way ANOVA's to see whether or not there ...
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0answers
93 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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0answers
12 views

What is a good statistical test to determine if cellular network A is faster than cellular network B?

I'm choosing between two cellular networks and my primary need is data. Out of curiosity, I thought I'd test the network speeds of the two networks statistically. On first glance, I find that ...
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0answers
59 views

Comparing multinomial logistic coefficients across groups

I have a multinomial logistic regression model - 1 DV with 3 categories and 5 IVs (4 continuous and 1 categorical). I would like to test whether my effects differ between different ethnic groups. Is ...
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1answer
81 views

Test for significant differences between groups (in R)

I want to assess whether the differences I find for different groups (of a factor variable) are significantly different from each other. Let's keep it hypothetical and assume a data structure like ...
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0answers
31 views

Comparing specific outcomes between groups of count data

I have results of an experiment for which an event was counted in 3 different groups. The count values range between a minimum of 0 and a maximum of 25. The count data are non-normally distributed. I ...
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1answer
17 views

Correlation between different variables and among the group

I'm not a statistician, just a learner and facing problem in my research. I performed experiment on 25 subjects and collected data from 3 different locations (muscles, say A, B, C). The experiment ...
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2answers
36 views

What statistics to use and How for “difference in differences”

There may be similar questions posted earlier but I am a novice for statistics and cannot discern them from mine, so I am posting my question as it is. What statistics can I use and how to use it (...
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0answers
7 views

Creating better groups

I have a number of groups from which I need to select next groups with same number of members. Each member has a certain number of features (metrics). New groups should be selected so that one of the ...
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0answers
18 views

Correlational Meta-analysis

I conducted a correlational meta-analysis. There were three groups of behaviours and one aggregate effect size for the correlation between each behaviour group and a continuous measure. We used ...