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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1answer
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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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1answer
41 views

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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21 views

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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1answer
23 views

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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10 views

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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1answer
55 views

Reject $H_0: \mu_1 = \mu_2 = \mu_3$ but not $H_0: \mu_1 = \mu_2, H_0: \mu_3 = \mu_2,$ or $H_0: \mu_1 = \mu_3$?

Is it possible to reject $$H_0: \mu_1 = \mu_2 = \mu_3,$$ for example, with an F test in the context of an ANOVA table, but not reject any of the following $$H_0: \mu_1 = \mu_2$$ $$H_0: \mu_3 = \...
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1answer
15 views

Comparing sets of independent sets with one another

This question is somewhat hard for me to articulate (I'm not extremely familiar with stats). My problem is this: I have a set of users, lets say User0-UserN. Each user has the potential to generate ...
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1answer
181 views

What were the main statistical contributions of Ronald Fisher?

Richard Dawkins has described Ronald Fisher as "the father of modern statistics and experimental design", a line which is quoted in Fisher's Wikipedia biography. And also Anders Hald called him "a ...
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14 views

Multivariate testing Student's T for dependant variables

I feel like this question has almost certainly been asked before but I can't find it anywhere - if it has been asked before a link would be a great answer! I have two sets of samples and I want to ...
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19 views

Encoding a set of vectors into 1 vector

I have a set $X$ that contains a set of vectors $V_i$ and I want to create a vector $u$ that represents each set. $V_i \in X$, $u$ is a representation of $V_i$. What are the possible ways of doing ...
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Contradiction between confidence intervals and Z-test

I've got the problem with Z-test and confidence intervals. Z-test rejects null hypothesis (proportions are equal), but confidence intervals are intersect. Let us consider 2 companies. The proportion ...
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2answers
229 views

Implement Fisher Scoring for linear regression

I know there is an analytic solution to the following problem (OLS). Since I try to learn and understand the principles and basics of MLE, I implemented the fisher scoring algorithm for a simple ...
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0answers
106 views

xtunitroot fisher interpretation

I would like to test if one of my variables is stationary (unemployment) with the xtunitroot fisher test. First, I do NOT include "trend" in the command and then I include "trend" - the results ...
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1answer
93 views

Fisher z-transformation and normality

I have 100 50x50 correlation matrices, which I have all Fisher z-transformed. I understood that this results in the all the entries of one matrix being approximately normally distributed. Questions ...
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1answer
31 views

Domain of Fisher z-transformation

We use the Fisher z-transformation for our correlation matrices, s.t. we arrive at approximately normally distributed data. As you might now, the Fisher z-transformation is equivalent to the function ...
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1answer
340 views

Boschloo or Barnard? Which Test for Cross Table Analysis?

Actually I am analyzing a 2x2 table from a small dataset of 30 patients. We are retrospectively trying to find some variables that give a hint about which treatment to choose. The variables (obs ...
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47 views

Which panel unit root tests should I use? Panel of 7 countries and 7 years

I have a balanced data of 7 years and looking into 7 countries. There are many panel unit root tests to be used. I am looking at using the Fisher-type and IPS tests but there are more than that and I ...
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70 views

Fisher LDA is a Bayes Classifier?

I've been going over many material in classification algorithms, and it seems that under the constraint that the covariance matrices are the same for a two-class problem then classifying a vector $x$ ...
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35 views

Non-negative Fisher LDA?

Is any one aware of any existing publication on non-negative solution for (Fisher's) linear discriminant analysis?. In particular: $$\text{maximize}_{w\geq0} ~ \frac{w^T(\mu_1-\mu_2)(\mu_1-\mu_2)^...
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1answer
37 views

Using Fisher LDA in R

I have run a large study looking at traumatic brain injury in patients I have conducted CT scans on patients very soon after the injury as well as neurocognitive testing and then repeated this at 1 ...
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37 views

Who first stated the relationship between ANOVA and linear regression?

ANOVA is usually thought as equivalent to linear regression, which is very interesting. Who first discovered this fact? Did Fisher know about this when he worked on ANOVA?
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75 views

Combinatorial Block Designs in Statistics

I am interested in description and references for how combinatorial designs (such as BIBD, Steiner triple systems etc.) are used in statistics (especially in designs of experiments and hypothesis ...
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1answer
267 views

Linear discriminant analysis (Fisher) = Bayes?

I'd like to ask a question, I am reading book right now about mail filtering, both methods: naïve Bayes and Fisher are there very similar in implementation. I am also writing a paper on Bayesian spam ...
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51 views

Solution of Fisher LDA

I'm trying to understand the Fishers LDA. In the book I am using there is explained that one has to maximize expression $$\frac{\left( a^T\cdot \bar{x}_2-a^T\cdot \bar{x}_1 \right)^2}{a^T\cdot W\...
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89 views

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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350 views

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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81 views

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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43 views

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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1answer
335 views

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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1answer
2k views

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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1answer
2k views

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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1answer
178 views

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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41 views

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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119 views

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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0answers
218 views

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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2answers
289 views

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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1answer
191 views

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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1answer
108 views

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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0answers
229 views

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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2answers
525 views

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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94 views

Orthogonal intersection in a Riemannian manifold

Let $S$ be the set of all probability distributions on $\mathbb{R}$ and $S_n=\{p_\theta\}$ be an $n$ dimensional submanifold of parameterized family of probability distributions on $\mathbb{R}$ where $...
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1answer
196 views

Orthogonal intersection of linear family and exponential family

I asked the following question in MSE for which I couldn't get any answer yet. I thought this would be a better place for that question. In statistical maniolds $S=\{p_\theta\}$,$\theta=(\theta_1,\...
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2answers
1k views

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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377 views

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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1answer
254 views

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. ...
2
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1answer
303 views

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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2answers
4k views

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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73 views

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 ...
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1answer
939 views

Fisher overall p-value vs. pairwise comparisons

I am doing comparisons on response rates across three sites. Following are the cell counts ...