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

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Comparing large categorical data sets with low or zero counts

I'm dealing with a biological feature which can be classified into $2^{20}$ categories. I also have two pretty large data sets of 1 and 3 million entries. Actually, only around 30 thousand categories ...
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0answers
17 views

How to approximate error on Chi-Squared Fit when bin counts are zero

I am using a galaxy image simulator that provides a 2D histogram that has the number of photons per pixel (bin) $N$. I am currently using a least-squares residual: $\sum_{bin}(f_{data}-f_{model})^2$ ...
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4answers
32 views

Two groups are significantly different? Test to use

I have two groups of discrete data (integers): ...
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1answer
23 views

prop.test: correcting for large number of observations

This is not really a coding question but more of a statistical question. I'm doing a proportions test on multiple proportions for many subjects. For example, subject 1 will have multiple proportions ...
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0answers
26 views

Different p-values between Wald Z and Wald Chisquare

I have used lme4 for mixed effects models of reaction times and accuracy rates. I could not use lmerTest because the type of model I was using are not yet implemented there (problem with predictors ...
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0answers
23 views

Overly-sensitive goodness of fit measure: where did I go wrong?

I'm using the chi-squared goodness-of-fit measure to evaluate instances of a fairly complicated model, but the evaluation is unbelievably sensitive to small variations in the model parameter values. ...
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1answer
97 views

chi square test or Z test?

SO I have an outcome from a biological experiment, where I have counted the number of dead cells upon a mutation. For example, in once case - out of 120 cells we saw 16% of the dead cells, but our ...
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1answer
59 views

Proper analyses for 2x2 contingency tables

So I have multiple questions about the different types of analyses that can be used on a 2x2 contingency table and when different analyses should be used. To open, I'll note that this stems from my ...
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2answers
88 views

Combining $\chi^{2}$ tests

I have a problem with statistics. I'm looking at whether variation in the concentration of a certain substance affects how strongly insects are drawn towards it. I did this by baiting insect traps ...
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1answer
17 views

Multiple value Chi Squared test in SPSS

I am currently doing a study into factors that affect mortality in a particular type of bacterial infection. I would like to compare certain patient characteristics. One of which is the specialty ...
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0answers
36 views

Chi-square test for one group

I'm struggling with this problem. For the analysis of my test, I was instructed to use chi-square test for one group. I use Statistica and everywhere I try to do this I need the expected values​​, ...
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13 views

Chi-squared test where observations can have multiple categories

I am investigating patterns in click-order on images. A user is asked to click on an image in 5 places (can be the same place). This sequence of 5 clicks makes up a graphical password. I am looking ...
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1answer
45 views

Why use chi-square (or other) statistic over regression modeling for 2x2 contingency tables?

I have a question regarding the use of logistic/log-linear regression vs. contingency test statistics, such as chi-square. Can someone explain to me why it would ever be preferable to use test ...
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2answers
70 views

Best way to test for co-occurrence of measures

I have some data with temporal measures over time. I'd like to test whether two binary variables co-occur more often than chance would predict, and I'm wondering the best (simple) way to do that. The ...
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0answers
19 views

Measure of probability of obtaining a certain $\chi^2$ given the number of trials

I am calculating an equation with several random components a large number of times, and in order to select my final answer I choose that with the minimum value for $\chi^2$. I am hoping to find some ...
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0answers
9 views

How to interpret merits in Weka with ChiSquaredAttributeEval and SVMAttributeEval?

I want to interpret the goodness of attributes using feature selection with 10-fold cross validation. With ChiSquared I get something like this (deletet attributes with merrit was 0 in all folds): ...
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0answers
5 views

Probability of certain value of $\chi^2$ given a number of trials

I am calculating a result and an associated $\chi^2$ via an iterative process that makes use of 3 random numbers (randomly sampling a Gaussian) in an equation, and I select as my final result the one ...
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3answers
45 views

Understanding $\chi^{2}$ and Cramér's $V$ results

I have two groups of buyers, A and B, and I want to test whether the difference between the percentage of them who would buy a ...
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0answers
20 views

Sampling weight, logistic regression and chi-square analysis [duplicate]

I have some questions. I am doing logistic regression. but my sample is small(n=129). And in DV, the smallest number of cases is 27(1'). Actually, I hope to use 12 predictors. However, I know the rule ...
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8 views

Which feature selection method to use for classification problem

I have to do some feature selection for a classification problem with numeric features. I am not sure which feature selection method to use. Chisquared test or Spearmann's rank correlation ...
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10 views

Independent Categories with multiple responses, chi-square too simple, MRCV log-linear model too complex?

Hello all and thanks in advance for your consideration, My research question is simple: Do lynx have a different diet in summer compared to winter? Data structure looks simple at first glance, ...
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0answers
10 views

$\chi^2$ goodness of fit - how to compute expected counts when $\exists$ unknown parameters [duplicate]

This isn't my original problem, but I'm posting a simplified version and then I'll try to see if I can apply it myself to my original problem. (yay for self-learning) Suppose I have a sample and I ...
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1answer
227 views

Is the beta distribution really better than the normal distribution for testing the difference of two proportions?

I'm working at an online agency, where we run a lot of AB testing in order to test differences in proportion between two groups (test vs. control). Standard practice in the industry for testing ...
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0answers
20 views

How to corretly scale sum of squared residuals of two different sets of data in order to compare them?

I did numerical simulations of two different systems that returned me N=1000 histograms expressed as $\{x,y,y'\}$, where $x$ is the independent variable, $y=P(x)$ is the probability distribution ...
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1answer
32 views

How can I do a chi-square test without being given the critical value table?

I have a random number generator that generate integers within [0, r). I want to write a piece of code to test whether the numbers from it are truly uniformly ...
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0answers
39 views

Combining chi-squared statistics

I have performed a survey in which users click on an image and the position of this click is recorded. I want to see if where a user clicks is independent of an attribute of the user (say gender). ...
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2answers
36 views

Multiple comparison on subgroups and overall comparison

I am trying to work out is there is any association between occurrence or not of an event in around 500 individuals and their randomised binary grouping (intervention vs placebo). However I also want ...
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2answers
48 views

Can Fisher's exact test accept a 'vector of probabilities'?

The R function chisq.test allows a 'vector of probabilities' to be set with the p argument. Is there an equivalent for ...
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0answers
18 views

Is it possible to take into account a variable that isn't really specified?

When you run a statistic test, is it possible to take into account a variable that isn't really specified? I'll give an example. We have to see if a certain word in a sentence is collective or ...
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1answer
56 views

Understanding the Chi-squared test and the Chi-squared distribution

I am trying to understand the logic behind chi-squared test. The Chi-squared test is $\chi ^2 = \sum \frac{(obs-exp)^2}{exp}$. $\chi ^2$ is then compared to a Chi-squared distribution to find out a ...
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1answer
32 views

Chi Square Analysis Percentages

I've used chi-square analysis in school, but was absent for the lesson, and I never quite got the hang of it. I've been successful with it in the past, but now I'm trying to use percentage values, and ...
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65 views

Is this normal to have big value of Chi Squared?

I am using chi squared for feature selection in text classification. However when I compute it I sometime have very big values. Like 100, 1000 or even 20000. Is this normal ? I wonder because I ...
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1answer
50 views

“Better” goodness-of-fit tests than chi squared for histogram modeling?

I work on data from a mass spectrometer that produces billions upon billions of count histograms, and I need a good way to test whether these histograms are consistent with one or several model ...
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16 views

Is it correct to compare two distributions of observed (that are means of observation) and expected values with chi square?

I have 2 classification methods that I want to compare. So I ran them on the same dataset and I obtained 2 different classifications. Then, I want to test if their classification is robust and how. ...
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31 views

Interpretation and understanding results from a chi square test for independence

I'm making a chi square test on data that has information about students. I want to find out whether there is a relationship between how well the students did on a particular test and the level of ...
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1answer
30 views

How to calculate degrees of freedom for chi squared test

I am very new to stats, and if the chi squared test is not the best way to handle this, please let me know. To simplify what I'm trying to do, I have many separate lists of genes. Each list is a ...
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0answers
32 views

Chi-squared test and binomial distribution

In some circumstances the Chi-square test can be replaced by a test based on the binomial distribution. The common issue with using the binomial distribution is that it may quickly become tricky to ...
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0answers
10 views

One-way Chi-Square goodness of fit and Cramér's V

Would it make sense to apply a measure of association test like Cramér's V on a 1xk table? I am a bit puzzled because in the literature phi and Cramér V are normally used on 2x2 or bigger ...
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22 views

Chi Square Test - Goodness of fit to test significance of incomplete system

A general question I'd like to ask. I have two systems, one has complete data, the other one we found only has 80% of data, the rest 20% is missing for reasons yet to be found. But for short term, I ...
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0answers
20 views

hypothesis testing in hierarchical trees

Suppose I have an hierarchical tree organising people according to their music preferences. Each person then has 3 extra properties A, B and C (e.g. parent's supportiveness on musical education). I ...
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0answers
28 views

What is the appropriate statistical test for Presence/Absence over time

I am assessing the presence or absence of a number of developmental milestones in mice in their first $21$ days of life. Each day, from the day they are born until they have $21$ days, I test if pups ...
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1answer
38 views

Which test to use to measure if target has been met?

The photo below is an example of the result i would like to obtain using the test which i cannot find in the article itself, i was hoping maybe any of you would know. I have tried to carry out chi ...
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1answer
32 views

Chi Square test to measure degree of association

I have a categorical variable with binary outcomes 0,1 (say Y), I want to study the association with other variables X1,X2,X3,X4,X5..... most of Xi's are categorical and few of them are continuous. I ...
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2answers
60 views

Multiple testing: contingency table or logistic regression approach for survey?

I have a survey asking a person's gender (M/F), geographic region (West, East, Midwest, South) and a few other demographic variables along with two dozen questions in which they can disagree / ...
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21 views

chi-squared multiple variables, what next?

So I am pretty new to statistics, forgive me if I sound dumb. I have two qualitative variables, with 4 and 5 levels, respectively (they are answers from a survey). I have arranged them in a 4x5 table ...
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0answers
16 views

Can Cramér's V tell me what to control for in my data?

For my research question, I want to find out if two different group types (IV) vary across position categories (DV) for eight different limbs. My data is nominal, so I'll be testing this by doing 8 ...
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1answer
50 views

Comparing proportions in two samples

(x-posted to Statalist) I have two (probably) independent samples taken from the same population under two different surveys conducted a few years apart. I'd like to check whether the frequencies for ...
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1answer
37 views

Which method of df for chi square I have to apply either $(c-1)\cdot (r-1)$ or df$=n-1$? [closed]

I have 10 question, based on 5 Likert scale choices. How do I find degree of freedom here in Chi square? Some one says use $(r-1)\cdot (c-1)$ but I think it will apply on categorical data, my data ...
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1answer
48 views

How do I find the expected values for this type of Chi squared question?

I have been doing exam papers and preparing for my exam, but I always can't do these type of questions in statistics, after I get to know how to do one, I'll be able to do these, which are ...
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1answer
39 views

N-1 Pearson's Chi-Square in R

I have two categorical variables and was looking into doing a chi-square test. I then noticed I had some low frequencies in my contingency table and thought Fisher's Exact Test may be useful. I've now ...