# 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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14 views

### Which statistical test for two subgroups of a same survey with categorical variables?

I have a survey with 20 questions (mix nominal, ordinal, Likert scale, yes / no questions). The respondents are professors from the Maritime studies. The hypothesis is that there is a significant ...
18 views

### When should you use association instead of correlation measurements?

I have a data set in which the variables are all categorical. I was wondering if I can examine the data using both correlation measurements (Spearman) and association (Cramer V) or taking into account ...
41 views

### Appropriate Statistical Test for Likert Data?

I am having trouble deciding the appropriate statistical test to use for a given experiment. In the study, participants first recorded various feelings on a 4 point Likert scale. Ex: How much do you ...
79 views

### Chi Square Test on small sample size

I have the following dataset and I am trying to run a Chi-square test between the control and pilot. The only issue is that, for a Chi-Square test to return proper results, the sample size need to be ...
53 views

### Reduced Chi^2 value interpretations below 1

I have an experiment where I have fitted an exponential decay over some data taken from a radioactive decay experiment. The fit yields a reduced X^2 of less than 1 What should be inferred by a X^2 of ...
85 views

### How do I compare two count data and show that there is true difference between them through Bayesian statistics?

I have two categories : Protein and Carbohydrate denoting two type of food available in a setup. From Protein, 335 food pieces has been eaten from a total of 1095 pieces and from Carbohydrate, 70 food ...
48 views

### Presenting the assumptions of Pearson's chi-squared test with Yates' Correction

One of the assumptions of Pearson's chi-squared test (for independence) is that expected frequencies are all >=5 in a 2x2 table OR 80% of the expected frequencies are >=5 in larger tables. If ...
24 views

### How is chi squared test used in this paper?

https://drive.google.com/file/d/1RCCoPbA6QTSyO_v-nmjCz5f7iV6V60kM/view?usp=sharing Kristiansen, S., & Severin, M. C. (2020). Loot box engagement and problem gambling among adolescent gamers: ...
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### Why is a 100 heads run surprising? [closed]

Assume we have a fair coin. We flip it 100 times. The outcome is all heads. Why is it that all heads outcome is more surprising to us than a "more random looking" outcome with less ...
18 views

### Is valid to conduct a CFA if p(CMIN) is significant

I conducted a CFA (confirmatory factor analysis). My values are: ...
52 views

### Which statistical tests do I use for two categorical variables with more than two subgroups?

I have two variables. The first (will call it X) is X=(morning, afternoon, evening, night). So, 4 categorical times of day. The other (called Y) is another categorical variable, i.e., Y=(cat 1, cat 2, ...
36 views

### Independence test for continuous random variables

For discrete random variables, chi square test of independence is a general test. By general I mean it is not possible for chi square statistic to be 0 when the variables are not independent. For the ...
12 views

### statistical test to compare proportions

This question might be basic so i'm sorry in advance. I'm doing an analysis trying to compare differences in proportions of two different groups (A and B) according to if they stayed on the same ...
32 views

### Alternative to Chi-square test for observations belonging to multiple groups?

Have a certain (high) number of rows corresponding to people. Have a bunch of independent variables which are group memberships and a dependent variable which is the outcome of a treatment. All are ...
29 views

### Chi square test with multiple comparisons and effect size using R

I have an 8x2 table and would like to conduct a chi-square test that is corrected for multiple comparisons and has an effect size. So far I have just used the chisq.test function in R. ...
20 views

### Proper Test for same proportions (multiple categories) on 2 groups, not normally distributed data, different sizes

I have trying to research the proper test for the following problem. I have 2 groups with different sizes n1 and n2. From each groups I am randomly sampling the same % of samples. (so say kn1 and kn2)....
28 views

### Interpreting chi-squared value returned by Excel 2010

I'm trying to assess whether the number of doubles (dice) being rolled by my opponents on a backgammon website are fair; to the naked eye they most definitely aren't but I need some science to back up ...
24 views

### Simple question on A/B testing

Hi there I have a question that I am confused as how to answer. So I have a balanced dataset of 500 observations split between 2 groups. 250 are a control group and 250 are an experimental group. The ...
23 views

### Comparing mark-recapture data

I’m running a trial for my supervisor in a fisheries position and it’s been a few years since stats. I have two groups of marked fish. ...
16 views

### Should I sum across variables before comparing proportions between groups?

I have the a dataset like the following: Experiment A B C Group 1 10 1 3 M 2 30 10 10 F 3 20 30 10 M 4 1 15 4 F And I am looking for differences in the proportions of A, B and C between the ...
138 views

### Is a chi square test appropriate?

I have a dataset which consists of fish density/biomass from two sampling periods (1 and 2) in two locations (A and B). In sampling period 1 locations A and B are both clear, while in sampling period ...
23 views

### How to perform a $\chi^2$ test when the expected value is zero

I have performed an experiment and obtained the following data: The black dots are the recorded values at a given time and the red line is a curve of best fit. Now I want to perform a chi-squared ...
32 views

### Flow cytometry on a couple of samples yields millions of cells so p numbers are tiny (even when sampling few individuals) - is this valid?

I recently did flow cytometry to quantify cell numbers on 4 similar samples from one group and 4 from another different group (n=4). The samples each contained millions of cells and I wanted to ...
19 views

### When to use strict = TRUE in power.prop.test()

I have been using power.prop.test() in base R for a long time, and just noticed the strict parameter defaults to FALSE, but the ...
21 views

### Is this use of chi-square test wrong?

Imagine I have three nominal variables (gender {male/female}, eats_salad {yes/no}, loves_life {yes/no}. If I wish to assess if "loves_life" is dependent on "eats_salad" I should ...
38 views

### Generalized Cochran's Q Test

I have two groups of experimental data samples that are categorical, and my goal is similar to Pearson's chi-squared test (${ \chi ^{2}}$), to evaluate how likely it is that any observed difference ...
52 views

### For feature selection ranking, is chi2 statistic and F value comparable?

I have binary and continuous features with a binary label. I want to do univariate feature selection with scikit-learn to short-list features for my model. For the binary features I'm using sklearn....
83 views

### Understanding Chi Square Post hoc test results

I'm using R and comparing the proportion of Male and Female authors from various academic journals (well, I think I am). Here's a table with my raw data: The code for it: ...
50 views

### Generalized Likelihood Ratio Test with null hypothesis defined by union of sets

Suppose you have a model with likelihood $\mathcal L(\theta;\boldsymbol X)$, where $\theta \in \Theta$ are parameters and $\boldsymbol X = (X_1, \ldots, X_n )$ denotes i.i.d. data. Likelihood ratio ...
79 views

### Difference between Chi^2, Chi^2/dof and R^2

I have radioactive decay experiment (so the model is y = Ae^(-kt)) results and am (slowly) teaching myself mathematica to plot this. I want to output some measure for the goodness of fit, but am ...
23 views

### Significance of subcategories

My data includes a total sum of around 30 different subcategories. If I want to find if the subtotal of these subcategories is significantly different from previous quarters I can run a chi square ...
139 views

### Correction for multiple comparisons for Chi-Square Test of Association?

Mock data: df = pd.DataFrame({ 'Treatment': [1, 2, 3], 'Success': [25, 29, 25], 'Fail': [48, 118, 92] }) Where 'Treatment' represents three independent ...
115 views

### diff-in-diff for binary outcome? (i.e.: Comparing proportions of two groups over two time points in paired setting)

Let's say I have students randomly split into two groups (treatment and control). Each student is given a test and they either pass or fail. They then either take a course (the students in "...
25 views

### Chi-Square Value too small for df = 6, am I using the wrong number of df?

I'm not very good at statistics so I figured I could ask here to see if anyone could help me. I need to do a goodness of fit test for a table of 7 data points: Energy Observed Flux Expected Flux 0.3 ...
98 views

### How to Calculate Degrees of Freedom for a Polygon with Correlated Arcs?

I'm running a bit in circles on this, so hopefully someone has ideas. Problem: I am trying to calculate the degrees-of-freedom (DOF; for purposes of calculating AIC) for a polygon. I am fitting an ...
12 views

### What to do after Brown-Forsythe test?

I am comparing the variances of three distributions and am relying on the Brown-Forsythe test. Apparently, at least one of the three distributions appears to have a different variance from the others (...
30 views

### Goodness-of-fit for discrete distribution - tails issues

In general, I want to see if a set of values comes from a certain discrete distribution (in this case integers from Poisson, or maybe gamma-Poisson). Chi-squared consistently comes up as the best GOF ...
36 views

### Use of Chi-Square test of independence / Fisher Exact Test?

One of my research hypotheses is that individuals from Southeast Asia who are ethnically Chinese are more likely to experience racially motivated hate crimes than their counterparts from other ethnic ...
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### Chisquare contingency under 5

I am working with a big data project, iterating over 30k features. There is a prt where I compare between several clusters (after kmeans), part of code: ...
21 views

### quasi-poisson / Neg.Bin / Chi-square for analysing annual count data?

I'm interested in looking at annual trends. The numbers represent the total number of a particular animal species that have been counted in that year. We see a decreasing trend, and I would like to ...
14 views

### A very big JB value in Jarque-Bera test [duplicate]

I have run the JB test for my data using two different commands. I am quite clueless about what conclusion I can make from the second picture which shows results of 0. This tells me that there is no ...
69 views

### Chi Squared Fit Statistic in Structural Equation Models

I am interested in structural equation modeling. I am trying to get to the bottom of how $\chi^2$ is calculated for a structural equation model. I understand that outside of structural equation ...
39 views

### Why doesn't it make sense to measure agreement with Chi square?

Why is it more useful to calculate Cohen's Kappa instead of the Pearson Chi Square test to measure the interrater agreement? Could someone please give me an example?
71 views

### Question on the chi-square test and Poisson distribution for significance testing

A quick question to check some reasoning: consider the chi-square test for a 2x2 table. For sake of argument, there's 500 patients in each group / category (male and female) and 10% of the total have ...
17 views

### Relationships in categorical data

200 study participants read a case scenario (lets make them hair-dressers, it might be less boring for you). Case scenario - male client with thinning hair - what intervention will you apply? Apply ...
41 views

### Understanding Pearson goodness of fit and deviation in R - using anova (test= Chisq)

I have run a Pearson goodness of fit and deviance to test the fit of the model but I don't quite understand how to interpret my output. I used an anova to run it: ...
10 views

### Finding relationships in categorical data

I have 200 health practitioners choosing one of six treatments after reading a case study. Then i ask them what info from the case study did they use to make their decision - info A, B, C, D or E (...
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### Chi-Squared Test of Homogeneity

Consider the table below that gives the proportions of a sample from each of two populations that fall into one of three categories (table edited after @whuber comment). ...