# Tagged Questions

This tag is very ambiguous. Use it when none of our more specific tags will work better: [fishersexact], [fisher-information], [ronald-fisher], or [fisher-transform].

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### where cells having (25%) expected count less than 5 than may be used Fisher exact test if not what test will b [closed]

where cells having (25%) expected count less than 5 than may be used Fisher exact test if not what test will be used example Abortion history
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### Using R: I want to create a contingency table with a 4 category variable [closed]

Currently I have data on SEX and outcome. For outcome there are 4 different values possible 1, 2, 3, 4. I want to create a contingency table (so that I can eventually do a Fisher test) such that I ...
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### Fisher's combined test vs testing uniform distribution of p-values

In testing a global null hypothesis, with independent tests, the p-values are distributed as $U(0,1)$. There are many goodness-of-fit tests to check that the distribution is uniform. For example, this ...
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### Small sample unconditional test of independence

Firstly, I will give the context and then my questions at the end. this is from the book: Categorial data analysis, Alan Agresti 2nd edition: (Small-sample unconditional test of independence, what ...
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### Biochemistry Table interpretation help!

I have a table that uses the Fisher LSD and has significance "in each column". I'm having trouble interpreting it. Is the significance just for that individual column or can they compare to other ...
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### Can Fisher's exact test be used with more than 2 binary variables?

Can Fisher's exact test (and the associated hypergeometric distribution) be used with more than 2 binary variables in a 2^k contingency table? Or is there some equivalent test and distribution to ...
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### I cannot use Fisher or Chisq test. What now?

I am trying to understand if there is a variance in the counts regarding two categorical variables. Gender Profession Salary F Teacher 12 M Teacher ...
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### Fisher information matrix with negative eigenvalues, fix through singular value decomposition?

I have the following Fisher information matrix (just an example): ...
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### Fisher test of periodicity

I have evenly sampled time series on which I applied Fourier transform. I am trying do determine if the signal contains statistically significant periodic components. I have succeeded with determining ...
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### A/B testing on non-stationary populations

I am running A/B tests on a website. The daily engagement level of the users varies wildly, with a strong weekly seasonality. (Basically, users who are willing to use the software on Sundays are more ...
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### What are methods I can use to calculate the two-sided Fisher exact test?

I am implementing code to compute the two-sided Fisher exact test of 2x2 contingency tables in C. I read that R's implementation is not the most efficient way to calculate the p-value for a two-sided ...
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### Post-hoc Tests for Fisher's Exact Test

I am running a series of Fisher's test to analyse some 2x2 contingency tables with small values. I have found significance. Is there anything equivalent to Cramer's V or the Odds Ratio or some sort of ...
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### Fisher's exact test in R - 2x4 table

I have a question on categorical data - I have a 2x4 matrix and I want to test the difference in the number of males or females in each group, and so I entered the data into R. So I input this: <...
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### Sample variance Fisher consistency

I am reading conflicting references regarding the Fisher consistency of the sample variance. $$s^2 = \frac{\sum_i^n (x_i - \bar{x})^2}{n}$$ Could anyone explain me how to proof whether $s^2$ is ...
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### Tests of independence for measurements of different magnitudes

Say there is a count table of observations Exon 1 Exon 2 Normal 1000 70 Disease 400 10 This gives a significant p-value if a ...
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### Is Fisher overestimating the variance here?

[NB: the title of this post used to be "Please help me decipher Fisher on ANOVA". I've edited the question to make it more focused, and modified the title accordingly.] Since anything written by R. ...
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### Test of Difference between 2 Sets of Pearson Correlations

Suppose I have two sets of Pearson correlation coefficients -- call them set A & set B, and they are of the same size. How do I systematically compare the correlations in A against B? E.g., I want ...
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### Computing p-values

I am a computer engineer, living in a digital world. I have no probabilistic background besides a probability course in the University and tried to grasp the Fisher's idea and have got the following ...
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### Distribution of p-values from multiple experiments

My experimental setup is the following: compute an optimal solution $S$ to problem $A$ on instance $I$, evaluate test statistic $f(S)$, compute $f(S_i)$ for $S_i$ $(0 \leq i \leq n)$ drawn from a ...
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### how to calculate E[vech(x x')vech(x x')']?

Supposing a vector x follows normal distribution. I want to calculate the expectation of the "fourth moment" in a vector form, meaning $\text{E}[\text{vech}(x x')\text{vech}(x x')']$, given that we ...
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### Apparent fallacy in Fisher-Irwin test

For a hypothesis $H_0\equiv p_1=p_2$ (for two Bernoulli distributions), we take a measurement and find that $X_1=i,X_2=j$, and we denote $k=i+j$ Now, to test $H_0$, the Fisher-Irwin test tells us to ...
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### Interpreting p-values

I am a little confused about what p-values mean under Fisher's signficance testing & Neyman-Pearson's hypothesis testing. Fisher uses p-values as a continuous measure of evidence against a null ...
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### Connection between Fisher metric and the relative entropy

Can someone prove the following connection between Fisher information metric and the relative entropy (or KL divergence) in a purely mathematical rigorous way? D( p(\cdot , a+da) \| p(.,a) ) =\frac{...
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### Statistical significance of increase in correlation

I have a sample with some individuals, and also three variables measured for each individual, let's say $A$, $B$ and $C$. There is a mild correlation between $A$ and $B$ and a mild correlation ...
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### How do you test for independence of k binomial variables?

I am analyzing some orthopedic data and our outcome is union vs. non-union of a fracture. One of our independent variables is whether or not the initial fracture was closed (skin intact) vs. open. ...
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### Comparing two nominal-scale response distributions

I have data from an experiment that consist of nominal-scale responses that subjects made in two treatments (the treatments are between subjects, not repeated measures). I've provided my data in data ...
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### Algebra of LDA. Fisher discrimination power of a variable and Linear Discriminant Analysis

Apparently, the Fisher analysis aims at simultaneously maximising the between-class separation, while minimising the within-class dispersion. A useful measure of the discrimination power of a ...
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### Confidence intervals based on asymptotic normality

I wrote a report about confidence intervals based on asymptotic normality. However, my supervisor said that the definition in the second paragraph is wrong, but I ...