A test (typically of distribution, independence, or goodness of fit) or a family of distributions related to such a test.

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Calculating p-value based on Chi-Square vs Z-Test incl Standard Error

I have been testing the significance levels for my various a/b tests. Degree of freedom is 1 so there's not a lot of complications here. So far I've been calculating my results using Chi-Squared ...
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34 views

Help with intuition about Chi-Squared distribution and its relation to Normal Distribution

At $\alpha = 0.05$, the significance cutoff of a Chi-squared distribution with 1 df is approximately 3.84, and that if we take the square root of 3.84, it's approximately 1.96, which is the 97.5 ...
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6 views

Should I use an Odds Ratio or a Likelihood Ratio to report prevalence of x in a Case-Control study?

I am trying to report the prevalence data for a case control study. I first ran a $\chi^2$ test on a 2x2 table of the prevalence data. I got a $\chi^2$ and Likelihood ratio result in SPSS. It ...
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3 views

How does Weka chiSquaredAttributeEval generates single attribute selection list while Chi Square itself is class based?

I have implemented my own Chi-Square ranker in C# however the example i found on the internet shows that Chi-Square ranks the each attribute within its class However Weka generates attributes as a ...
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16 views

Reverse solve chi-squre statistic to find number of observations

I am trying to prove that two proportions are equal with 95% confidence. I have a total population Tp (10000), and wins in that population of Wp (2000). My sample size is Ts (1500). I need to solve ...
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79 views

Independence of two categorical variables & chi-square

I have data as follows: ...
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7 views

Error estimation in a two parameter non-linear model

With a dataset of $N = 26$ values for $n = 7$ different species (some species with 3-4 data points, one or two with 5)I've found the average value $y_i$ and standard deviation $\sigma _i$ for the $n$ ...
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23 views

How to use permutation test to create null distribution for categorical data?

Consider a population of 1,000,000 individuals. I have examined them all and identified 1000 samples which I believe are not like others. To confirm this I analyzed the 1000 sample regarding one ...
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8 views

“Goodness for fit Chi” test on point pattern

Apologies, I have a few question today I hope there is no limit to how much I can ask here before you start billing me :) What is the meaning of Goodness for fit Chi-sqaure test? From the wikipedia ...
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1answer
38 views

Are Pearson test and Chi-square test the same

I'm a bit confused with Chi-square and Pearson. I know Chi-square is: Chi-square = E (sum of) (Oi - Ei)-square / Ei What would the Pearson formula be if it is different? I don't think it is ...
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5 views

How to evaluate the quality of Bayesian network sampling?

I have generated a sample from a Bayesian network by applying Forward Sampling. I learn the parameters of the network (the same structure) from this sample so as to evaluate the quality of the sample ...
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18 views

Scaled vs. unscaled Chi-square statistic in CFA / GRM fit evaluation

I generally want to assess the fit of a CFA model with ordered categorical indicators (the graded response model, GRM). There are two versions of this model, the normal-ogive GRM (ordered CFA with ...
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34 views

chi-squared test of two row table while calculate cells in row 2 from total n of row 1- is this valid to do?

I have count-data of patients with an event which occurred on different days in the week. For example: ...
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20 views

How to apply Chi Squared test according to this Simulation?

I would like to introduce the following scenario to better clarify my question: Let's say that one day while doing research on the city of Villy God has appeared to me and told me that city there are ...
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27 views

How to compare groups when the control group is 100 times larger than the group in question?

I am working with NIS data which are basically a 20% sample of all in-hospital admissions in the US every year. I have small group of cases that carry diagnosis "X" in their record and overall the ...
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22 views

Is chi-squared an appropriate test in this scenario?

I have tested two separate testing tools on a sample of people. Each tool splits people into three separate categories. My questions are: 1) Is there any difference between the allocation of people ...
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16 views

Chi-squared goodness-of-fit test and conditional probability distribution

I have three discrete variables, let's say $A, B,$ and $C$. The number of possible values of $A$ is 3, and $B$ and $C$ take binary values. I also know the probability distributions, $Pr(A | B, C)$, ...
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34 views

Chi-square testing with demographic data viable to compensate non-response bias?

(Hello CrossValidated, first poster here, so please have mercy with any transgressions of mine!) For my thesis, I am currently researching the correlation between stance to organizational change and ...
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11 views

Orientation of point dataset

Looking at the well-known Pine dataset (Numata, 1961) it appears in different articles in different orientations. 1983 Digggle: Then sometimes appears rotated: Or even flipped: Other than ...
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12 views

Comparing count groups/hisotgrams with different bins

I'm looking at clustering techinques for which I have a ground truth. From the ground truth I can extract the cardinality (size) of clusters and I would like to test how well different methods can ...
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60 views

The statistical significance of a single regression model

I currently have a neural network regressor which is tested on 45 samples. The TRUE response variable has a mean of $\mu$ and standard deviation of $\sigma$. What I would like to do now is test ...
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15 views

Can I use Chi squared to compare proportions?

So I have these 3 animals, and they spend time in 5 different habitats (sum of time spend is 1). ...
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48 views

Which Test to check relationship between age (ordinal independent variable) and nominal variable (type of car)

I have two variables age and type of car bought. Age is in groups. Eg. $<25$, $26-35$, $36-45$, $46-55$, $>55$. Car is 1. American, 2. ...
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6 views

Dichotomous independent and dependent variables chi square

Is it possible to run chi square on independent and dependent variables that are both dichotomous (e.g. "0-No" and "1- Yes")?
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2answers
50 views

t Test, Chi Squared or logistic regression..?

20 subjects Day 1. Shooting test - Basketball free throw shooting accuracy (number of successful shots out of 10) Day 2. Given coaching and can practice technique. Day 3. Shooting test again (as ...
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1answer
22 views

Why does my power vary markedly between a z-test (2 proportions) and a chi-squared test?

I have two groups, with 100 people in one group(1) and 80 people in the other group(2). 42% of group 1 love cake. I am wondering what proportion of the 80 group 2 members would need to love cake for ...
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2answers
16 views

Chi-squared for multiple samples

I have a set of data from an experiment where people are asked to remember items of different types; let's call them A, B and C, such that they can either recall them or not. Here is an example ...
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32 views

How do you determine when to use certain test statistics?

I've been trying to formulate this question and have struggled, so if it seems ill-worded, I apologize: A statistics book I have has a table in the back that says: For an inference test regarding a ...
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18 views

Feature Selection using chi Square (Accord.Net)

I have data that looks like This is mock data. Let us assume that Sandal,Sneaker,Leather , Boot etc are somehow predictive of 2 classes (male and female) . What is the easiest way to get the chi ...
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26 views

Zero columns/rows in chi-square test

I work with CHAID method, which is based on Chi-square test of independence. All my independent variables are numerical, so I convert them into ordinal via intervals. I have to adjacent categories (2 ...
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19 views

Expected value for an “Other (please specify)” option

As recommended in the answer to this question, I'm going to use a Chi-squared test to find the probability that the four answer options for a multiple-choice question were selected randomly. However, ...
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10 views

pairwise chi square test for independence on large df

I have a data frame (mydata) of discrete data (binned 1 through 10) where each column represents a variable I'd like to use in a Naive Bayes algorithm and each row represents a city throughout Europe. ...
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21 views

Is it possible to carry out a one-tailed chi square test in Stata?

I am trying to understand whether there is a difference in proportions for a dataset in two time periods using a 2x2 contingency table. The null hypothesis is that there is an expected increase ...
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41 views

$\chi^2$ is insignificant when Spearman's $\rho$ is significiant (and vice versa)

How can I interpret a situation where for two variables on an ordinal scale: $\chi^2$ test is not significant (p > 0.05) and Spearman's $\rho$ is significant $\chi^2$ test is not significant and ...
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23 views

difference between two correlations measure methods

I am trying to measure the correlation between two binary categorical variables. I tried in two ways. Use the chi-square test for independence of two-way table. The p-value as the correlation. Treat ...
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1answer
34 views

Chi Square test on data with the null hypothesis being the data is uniformly distributed in R

I've a variable x with 1000 observations.My goal is to prove what kind of distribution e.g.(Uniform or Normal distribution) using Chi square test.Before to this test i've plotted histogram and ...
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16 views

Is Chi Squared correct for ordinal vs ordinal correlation?

I have grown some bacteria using using two different methods (NUTRIENT1 and NUTRIENT2). The response variable is ordinal, categorical: No Growth, Scanty Growth, Low Growth, Moderate Growth, High ...
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31 views

Do I have binomial data, and how do I treat it?

I have field observations that are essentially presence/absence, but here are the details: randomly placed quadrats are divided into 10 squares. The field data recorded are the number of squares which ...
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18 views

Transformation of sum of Gammas into Chi-squared with a Casella Bergian twist

My question is very similar to the ones asked before (I have looked at all of them on Cross-Validated) but it is more about house-keeping and making sure it matches precisely transformation theorems ...
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17 views
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9 views

Chi-squared test between a set and its subset

I have a set A and I know that 10% of people in the sample visited a www.site-A.com. Now I extract a sample B, subset of A, of people that have visited www.site-B.com and I assess that 12% of people ...
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55 views

Is chi squared test appropriate

I have conducted a survey in which the participants were asked to answer questions using 3 different techniques. At the end they were asked which technique the preferred, the results are as follows A ...
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23 views

Fit raw data to distribution and use chi-square

I have a dataset of number of tweets over time similar to this: ...
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21 views

Analyse the difference between the selection of several options

I observed several test subjects (insects) for several days. All of them had the possibility to choose between 8 options (different ways to go). It was supposed, that all 8 options have the same ...
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1answer
82 views

Implementing chi-square in python and testing on scipy's poisson and norm variates

I need to implement Pearson's chi-squared test to test random variates. But I get very different results using different sequence length,degrees of freedom or even seeds. Only a few times sequences ...
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35 views

Statistical analysis, what test should I use?

I have categorical data collected from a questionnaire. It's mainly (Yes/No/Don't know) answers with the exception of the name of the software. I'm doing a security analysis on different kinds of ...
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13 views

Finding p-value from Chi Squared and df

So I have calculated my Chi Squared values and my degrees of freedom, now I would like to calculate the p-value. I have found plenty of calculators to do it, but no explanations.
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18 views

Is it safe to assume that $\ln{L} = -\frac{\chi^2}{2}$?

I have written a code that fits a 2D model image to some observed 2D image. One of the optimization libraries I use (MultiNest) in order to do that requires to be ...
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26 views

Residual Chi-Squares are not computed because of redundancies

I am using Logistic Regression to test the impact of a group of IV on a binary dependent V. I was not able to get the value of residual Chi squares. the error received in the output table is ...
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1answer
23 views

Wald Statistic univariate case

The Wald statistic in the univariate case $T_w = \dfrac{(\hat{\beta} - \beta_0)^2}{I{(\hat{\beta})}} \sim \chi^2(1)$ where $\hat{\beta}$ is the ML estimate of $\beta$ and $\beta_0$ is the null ...