Questions tagged [chi-squared-test]

A test (typically of distribution, independence, or goodness of fit), for the family of distributions use [chi-squared-distribution].

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Definition of Corrected Contingency Coefficient

I quote RACHEV, HÖCHSTÖTTER, FABOZZI, FOCARDI (2010). Starting from the bivariate variable $(x,y)$, with the component variable $x$ taking values in $(v_i, i=1,\dots,r)$ and the component variable $y$ ...
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Are there small-sample cases where we can approximate the distribution of the Wald statistic better than with the Normal/Chi-squared distribution?

In my specific case, I'm referring to the parameter estimates of a binomial regression (regardless of whether we are estimating risk ratios or odds ratios). Can the problem of divergence of the Wald ...
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Chi square test on proportions within hierarchical data [closed]

I have a dataframe such as : In that dataframe I have 4 groups (G1,G2,G3 & G4), and within each group I have 3 modalities (...
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Chisq test for significance of intercept in R

I have a logistic mixed-effects model with both fixed and random effects. Imagine something like: ...
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Interpretation of 'incorrect' results of chi square test

I use the chisq.test() function for the goodness of fit test. I run the test through a range of variables, and in some cases get the following message: In chisq.test(TBL_all_f) : Chi-squared ...
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How to decide which variables to keep in logistic regression model based on anova(model, test = "Chisq") and glm output [duplicate]

I’m new to logistic regression and was hoping for some help in picking a "best fit model". Say I have a group of students who are assigned a job after college. Everyone can request their top ...
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Analysis of count data: Poisson regression, chi square, or Kruskal-Wallis?

I have collected data on how many events occur (as counts) across three groups: control, sham, experimental. I have also collected continuous data such as body mass, wing length, along with age. My ...
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Spearman rank after Pearson chi-square

I'm considering to use the Pearson chi-square test to see if two categorical variables are significantly associated. If the association is significant I want to apply the Spearman rank test to see if ...
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Categorical data: 2 x 2 x 2 Chi2 test with moderator, Tarone statistic is significant. How to compensate for violation of underlying assumption?

I am performing Chi-Square tests and, with a moderator variable: a 2 x 2 x 2 with an examination of the Mantel Haenszel Chi-square statistic. The problem:there is an underlying assumption of ...
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Chi-square testing help

Let's say I have the following groups: Controls : [239.473, 247.451, 259.486, 254.329, 240.195] Experiments : [252.568, 313.24, 292.972, 269.032, 260.48, 246.808] My goal is to see if there is a ...
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categories for chi-square test of independence - what if categories are determined by TWO variables?

My categories are the combination of two variables. For example if I have two age bands and two sexes, the categories are old women, young women, old men, and young men So on the one hand there are ...
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Can these data be grouped?

Whithin a certain population, I have selected three samples (in three different periods of time) and determined for each the frequency of individuals that present a specific characteristic. I want to ...
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chisq.test with p-value=1

I have simulated 10.000 observations for the gender of a population. The simulated count data is called gen.simcount and the marginals I gave as input for the ...
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Using chi square when expected value is 0

In a class (I'm the teacher), we are crossing Drosophila with different traits to see if they inherit some characteristics on autosomes or sex chromosomes. In order to do that, we do reciprocal ...
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Converting likelihood ratios hypothesis test from equality to inequality

I have the following LR test for proportions (to anyone familiar to applied statistics in finance, this is known as the Christoffersen's unconditional coverage test). We would like to know if $\pi$ is ...
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Paired/unpaired samples vs dependent/independent samples

I know that there are a lot of questions about these four terms on this website, but I didn't see rigorous statistical explanations in them, and at least half of them use term "paired samples&...
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How does Chisq.test() calculate degrees of freedom from two vectors as opposed to a matrix?

I'm confused about the way chisq.test() is handling a very simple table from an exercise where I asked students to "sample" a bag of M&Ms and compare their scope to the pooled samples ...
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Using chi square test to determine representativeness of sample drawn from known population

I am trying something out of my comfort zone and would appreciate any help provided! I have used census data to identify the frequency of age brackets in my town. I then sampled about a thousand ...
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Interpretation of Odds Ratio (OR) in Fisher's exact test [duplicate]

I've tried using R operating Fisher's exact test to test for independence of the 2 datasets below and struggling to interpret the Fisher report. Please have a look at the data and the Fisher's test ...
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What's a good hyptothesis testing method of non-gaussian distributions?

Let's say I have a single set of measurements, $M$ comprised of $N=10^4$ values (or so, I can increase if neccessary). The distribution of values are not gaussian. What I want is to gather $N' < N$ ...
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Interpretation of Odds Ratio (OR) in Fisher's exact test

I've tried using R operating Fisher's exact test to test for independence of the 2 datasets below and struggling to interpret the Fisher report. Please have a look at the data and the Fisher's test ...
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Formalization of statistical model and hypotheses for chi-squared goodness of fit test

I want to rigorously formalize the statistical model (i.e. the set of "allowed distributions") for the chi-squared goodness of fit test (when the probabilities of intervals are fixed and don'...
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Is there a specific term for denoting samples that are used in a test of independence?

I know that there are independent samples and paired samples (paired samples is a special case of dependent samples of equal size). In any test of independence we have a pair of random variables $(X,Y)...
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What uncertainties to use when fitting a distribution model to binned sample data?

A common task is to fit to a sample of $N$ data $x_i$ (assumed 1D for the sake of argument) a model $p(x|a)$ (normalized to unit integral) for their distribution with some parameters $a$. One way is ...
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Goodnes of fit - observed and expected values

This is a basic question but I'm confused at the moment, and, can't unlock this concept even after digging about it. I'm trying to do "Goodness of fit" and I think that I'll go for the "...
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How to test for significance for binomial count data where the expected outcome is unknown?

Description of the data: The study is investigating whether conversations on a messaging app are greater or less than 8 words long. The variable is the count of messages that contain more than 8 words ...
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Sample size recommended for a chi-square test for the variance

I have read that chi-square test for the variance requires the sample to be large enough. In this answer: p-value and equivalence testing, the chi-square test for the variance is suggested for a small ...
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Adding covariates in chi-squared test or proportions test?

I am having trouble figuring out what analysis is appropriate for my research question. I've been googling for the past few days but couldn't find the answer. I would greatly appreciate it if anyone ...
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Calculating statistical significance on survey results [closed]

Consider a single survey question: "What is your favourite color" with 4 possible responses: blue, green, red, yellow If I've collected 100 responses: blue 20 green 40 red 35 yellow 5 How ...
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Statsmodels tests for proportions give different results than other software [closed]

An example from Primer of Biostatistics by Glantz: 8 patients out of 61 died while undergoing heart surgery with one anesthetic. With another anesthetic, 10 patients died out of 67. If we use R, chisq....
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Normality of multivariable regression residuals - degree of freedom of chi-squared

I am doing multivariable regression modelling on a sample of n elements with m independent + 1 dependent variable. I used the OLS (Ordinary Least Squares) method to determine the beta vector of ...
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How to measure the strength of association between two variables where majority of pair are assosiated?

I am quite new to the stat so facing a huge problem in result extraction, I have a large dataset running ~19000 (genes) x1500 (patients). I would like to see the dependence between two variables (one ...
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In R, trying to find the confidence interval for the difference in proportions

I am comparing two different groups based on working status. For this instance I am looking at occupation so I have a table that looks like so: ...
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Chi-Square test with relative values?

I am working with a weird data set and it is driving me crazy. Survey respondents (a,b, c,...) were asked to each distribute 15 points among 3 different preferences. Accordingly, every preference can ...
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Calculating sample size for chi square independence test with gpower?

Using gpower I can only see a goodness of fit option, but I want to calculate sample size needed for some effect size and power of a Chi square independence test. Is it correct to say that Chi square ...
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Paired n-way comparison of proportions

my stats are a little rusty and I have a somewhat complex experiment to analyze, so I wanted to seek some advice. My experiment: I collected survey data from 150 participants. 75 of them completed ...
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Tranforming Breusch-Godfrey and Ljung-Box Tests: Canonical Rotation of Portmanteau Tests

Breusch-Godfrey and Ljung-Box appear to be optimizations of Chi-Square. Recently I noticed a library in R that transforms a Chi-Square to a Phi Four Point Coefficient (...
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What test should I use for correlation of categorical and discrete variable in R?

Here is a a portion of my data: ...
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Ranking subjects above/below model regression line

I want to rank subjects in terms of them being above a model regression line. I created a table where each row is a unique ID and there are columns ...
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Best statistical test for aggregated group rate vs individual rate?

I'm looking to test the difference between an aggregated group weight (weighted average) vs an individual group rate? For example: Let's say we have 4 companies: A - 35/60 = 58% B - 120 / 400 = 30% C -...
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global significance of glm model

I am a beginner regarding GLMs and R. I have built the following glm model: ...
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2by3by3 Chi-square test [duplicate]

thanks for reading my question. I planned to do a 2by2by3 Chi-square test , and ask how variable A (condition, 2 levels: Cued and Uncued) and variable B (group, 3 levels: English, Spa-Eng, and Chi-...
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How to take into account several p-values results?

I have a theoretical question about which is the best way to extract a result from a series of p-values obtained by using several times a 2x2 Chi Square test. I have 2 variables to take into account (...
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Degrees of freedom for a $\chi^2$ with non-linear polynomial model

I have a $\chi^2$ below for some model function $F$: $$ \chi^2 = \sum_{i=1}^{i=M} \frac{\left(y_{i}-F\left(x_i;\vec{a}\right)\right)^2}{\left(\Delta y_{i}\right)^2} $$ I know that non-linear model ...
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How can I do chi-squared tests on missing data?

I have a large dataset looking at how race is recorded. I want to see if there is an association between race being recorded in a specific dataset and not being recorded in another. For example, if ...
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What to Choose and Why ? Chi-Square or Mutual Information for Categorical Feature Selection

I am working on an ML problem. The dataset is of shape (15036, 216) containing all categorical variables. The task is to select the top 10 features which are applicable using any two feature selection ...
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Floating Normalization of Experimental Data Sets while Fitting Multiple Models

I have $N$ data sets of unequal cardinality, and I am told we do not treat each data set with a normalization of $1$. Instead we let the the normalization float and fit it as though it were any other ...
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Is the Chi-Square Test for Association more powerful than a Chi-Square Goodness of Fit Test?

Is the Chi-Square test for association (comparing two proportions) or a Fisher's exact test more powerful than a chi-square goodness of fit test (comparing multiple proportions to determine whether at ...
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Do we check for association between categorical variables before clustering mixed-type data?

I am clustering mixed-type data using hierarchical clustering and the Gower measure. My question is: Do we have to check for association (dependence) between categorical variables (e.g. using chi-...
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between-group multinomial test

I'm having some trouble to decide what is the best method to analyze a between-groups / multinomial problem. For simplicity, I'll use an example: Let's say I want to compare basketball shooting ...

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