Tables of counts (occasionally proportions of marginal counts), arranged by (at least) two marginal categories, displaying bivariate or multivariate frequencies. Sometimes called crosstabs.

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124 views

How to simulate effectiveness of treatment in R?

Let's say I want to write a simulation for the table below to decide if Xylitol treatment and ear infections are independent. How would I go about doing this?
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1answer
25 views

chi-squared / Fisher's exact test with incomplete data for contingency table

I have a treatment group (n=42) and a control group (N=12). From this this, 13 used in the treatment HTN drugs and 4 people in control group used HTN drugs. How should the contingency table be set ...
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0answers
28 views

Test of Independence Between Two Nominal Variables With Many Levels Each

I am looking to test whether there is a significant relationship between two nominal variables, one which has 100 levels and the other with 10 levels. I initially considered doing a $\chi^2$ test of ...
2
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1answer
75 views

Computing the power of Fisher's exact test in R

Suppose that I have the following 3 x 3 contingency table: ...
2
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0answers
24 views

A question about the distribution of the log odds ratios in multivariate contingency tables

I know that in $2 \times 2$ tables, one may compute the standard error of the log odds ratio by the formula $$\sqrt{\frac{1}{N_{11}} +\frac{1}{N_{12}}+\frac{1}{N_{21}} +\frac{1}{N_{22}}}$$ where the ...
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1answer
40 views

how to compare two percentages to prove for statistical significance

I have problem to compare the two percentages and to get the statistical significance for these two different percentage. I just want to approve whether these two percentages are significant or not ...
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2answers
343 views

What distribution does Fisher's exact test assume?

In my work I have seen several uses of Fisher's exact test, and I was wondering how well it fits my data. Looking at several sources I understood how to calculate the statistic, but never saw a clear ...
3
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1answer
32 views

Denominator term in Chi-Square-Test for association in a contingency table

The general formula for the Chi Square Test for association in a contingency table with $I$ rows and $J$ columns, and cell counts $n_{ij}$ is $$ \chi^2 = \sum_{i=1}^I \sum_{j=1}^J \frac{(n_{ij} - ...
3
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0answers
25 views

chi-squared test vs fisher's test vs … => highly unbalanced length frequency data

I would like to statistically verify if two distributions are identical. Basically, the first distribution is a length frequency distribution from a large population ("population"). The second is the ...
2
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1answer
73 views

Chisquared on categorical data or a Wilcoxon test on the counts hereof?

This question is related to a question I had in R on SO here The background of my question is fairly simple. I was given two "databases" in the form of data.frames ...
0
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1answer
18 views

How to perform a conditional cross-tab in R or Excel? [closed]

I recently was given a project which consists of: pulling together words from ~500 small tweets and doing a matrix, which shows which words occur together in which tweets. I am wondering how I can ...
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2answers
87 views

Hypothesis testing using R

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1answer
19 views

Log Linear Models: Interpretation when None Fit

This is question 9.6 from Categorical Data Analysis by Alan Agresti (Wiley, 2013). The question asks us to find a Log Linear with the best fit for a 2x2x2 contingency table. The following are the ...
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0answers
6 views

How to adjust logistic models in case bivariate analyses encounter issues?

The model looks like: Y = X1 + X2 + ... + Xi Y is categorical or, to be exact, ordinal Xs can be categorical (dichotomous, ordinal, nominal) or continuous I first run bivariate analyses between Y ...
2
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0answers
26 views

Does N-1 correction for Pearson's Chi-Square apply to r x c tables generally?

Campbell (2007) recommended what he called the "N-1" correction for chi-square tests performed on two-by-two contingency tables. He described the correction as: "the K. Pearson chi-squared test ...
0
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0answers
35 views

How to enter data into contingency table directly?

I'd like to create a contingency table. I do it using: matr=matrix(c(62,61,36,19,10,21,58,60,39,22,12,19,91,83,72,23,52,62,43,28,59,57,29,20,12),5,5) but it ...
3
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1answer
95 views

Hypothesis testing based on Likert type data

I know this site is full of similar questions, but either their answers do not apply, or I'm missing something. I have data from a questionnaire. Responses are in the form of Likert items, some of ...
0
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0answers
50 views

Seeking basic advice re. contingency matrix for time-limited predictions

I am looking for advice on how to construct a contingency matrix ... A subject is measured on day 1 and a score is computed. This is repeated daily generating a series of scores. If on a given day ...
0
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0answers
32 views

Two tails or one tail McNemar's test in a binary classification problem. Which one should i choose?

I'm using McNemar's test for compare two designed models in a binary classification problem. As you know we have two kinds of this test. ...
1
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1answer
321 views

3x3 contingency table: what to use instead of chi-squared test?

I have questionnaire data from subjects divided into 3 groups, G1, G2 and G3. Subjects had to answer a question, and they had the options A1, A2 or A3 to choose from. The correct answer depended on ...
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0answers
20 views

test to show statsticial change due to an intervention

I have a group of 222 test results that were reviewed separately by two interpreters X and Y. Based on their assessment, they were to assign management into 4 categories A, B, C and D. Then another ...
2
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1answer
109 views

stats for 2x4 contingency table with both very large and small or zero counts

I have 7000 2x4 contingency tables with count data. They represent a particular position in a genome and the number of times each dna nucleotide is observed at that position in 2 different ...
2
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0answers
31 views

Visualise significant differences in a contingency table?

I'm working with pandas and scipy, and I would like to find a quick way to visualise unusual values in a contingency table. Say this is my contingency table: ...
0
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2answers
63 views

Logistic regression, Chi-square, and study design

I have a study in which I have developed a new predictor (binary) for a disease (also a binary variable). The study has two parts. In the first part, I want to test if my predictor is strongly ...
2
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0answers
116 views

2x2 contingency table - maximum likelihood estimate of the odds ratio and exact confidence intervals

I have two questions regarding the following 2x2 contingency table: 1, How can I derive the maximum likelihood estimate of the odds ratio ($OR = (a*d)/(c*b)$) 2, How can I derive exact confidence ...
2
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1answer
150 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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1answer
104 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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0answers
62 views

How to report log linear models of contigency tables

I am using log linear models (loglm function, library MASS of R) to evaluate if 3 variables ...
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0answers
85 views

Testing specific categories after Fisher's exact test in 2 x k tables

I have two variables, one with 2 categories and one with 6 categories. To test, whether there is any relation between these variables, I performed Fisher's exact test, which gave a significant result. ...
2
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1answer
243 views

Why use G-test and the likes for AB testing at all?

I am learning about AB testing using the G-test. In my example, I have a 2x2 contingency table. ...
2
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2answers
139 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 / ...
0
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1answer
35 views

Using split function in contingency table [closed]

I am quite beginner in R and I want to do a task that I think is manageable but I am still figuring out how. I have a contingency table like this: ...
2
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0answers
186 views

Contingency tables, Chi-Squared analysis and next steps in R

I'm hoping one of the more experienced R programmers/statisticians out there can help me with something, or explain why what I'm trying to do is stupid :-) In the past, I've done analysis of survey ...
0
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0answers
57 views

Which contingency method to use with a 3x3 table yet still account for expected or discrete choice?

Im not sure what test to conduct when I have 3x3 matrix of data and still account for availability. So, in a simple chi square you have an observed observation and then you are often able to ...
0
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0answers
28 views

Help with calculation of crossing more than expected from observed vs simulated data

I want to know if moose are crossing water more than expected. I followed the methods written in Beyer et al 2013 which I am now completely confused as to how to actually do the analysis. I am ...
1
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1answer
34 views

Coerce contingency table to report unrepresented classes [closed]

I have a contingency table computed from the out of sample observations. In some cases not all classes are represented in the out of sample and hence do not appear. I want to coerce the contingency ...
0
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0answers
80 views

Model selection of multinomial logistic regression for 2x3 contingency table

I want to analyze a 2x3 contingency table using multinomial logistic regression and I hope to be able to do it in Matlab or in R. I have looked around in old threads, but haven't been able to find a ...
0
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1answer
109 views

Alternative to Chi-Square, etc for categorical variables

I am trying again to explain my problem, and I have more concrete results. I have tried every potentially relevant test I can find, and none seem to work quite right. The question is illustrated ...
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0answers
49 views

Probability of Event from a table

I have the following table: From here I want to answer the following question: P(CHILD CAN RECOG BEG SOUNDS OF WORDS – YES | CHILD RECOGNIZES LETTERS - Most of them). From my understanding of ...
1
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1answer
161 views

Meta-analysis of RR and OR calculated from 2x2 tables in R using metafor

Background My question concerns the calculation of risk ratios and odds ratios for meta-analysis using the metafor package. I know it looks long, but please bear ...
0
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1answer
697 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 ...
7
votes
2answers
402 views

Bayesian analysis of contingency tables: How to describe effect size

I'm working through the examples in Kruschke's Doing Bayesian Data Analysis, specifically the Poisson exponential ANOVA in ch. 22, which he presents as an alternative to frequentist chi-square tests ...
0
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0answers
19 views

One-Tailed Fisher's Exact Test [duplicate]

How can I calculate p using a one-tailed fisher's exact test for a 2x3 (or 3x2) contingency table using excel? I found the formula ...
0
votes
0answers
58 views

Cochran-Armitage test for trend in a contingency table

I have a 2x4 contingency table and I'm testing for a monotone trend. How can the weights (scores) be applied in the following situation: The 1st category is expected to have no effect on the ...
1
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1answer
38 views

Name of this simple descriptive method for showing crosstable combination typicalities?

This might be a basic question, but I have no clue what this descriptive method could be named. Simplified, I have a cross-table with Occupations (e.g., doctor, lawyer, engineer) as rows, and Hobbies ...
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1answer
71 views

Sequential importance sampling for multi way contingency table

Full disclosure: this is a homework problem. I'm having a really hard time understanding the algorithm for applying SIS to contingency tables or what it even means to do sequential importance sampling ...
3
votes
1answer
2k views

How to interpret Cochran-Mantel-Haenszel test?

I'm testing the independence of two variables, A and B, stratified by C. A and B are binary variables and C is categorical (5 values). Running Fisher's exact test for A and B (all strata combined), I ...
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0answers
37 views

Testing association between two categorical variables, with repeated experiments

Say you are counting sharks and whales in the Atlantic and Indian occeans and want to check if eg sharks prefer the Atlantic and whales the Indian occean, as described in the example here. But instead ...
0
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0answers
21 views

How to compare the fit of two tables of percentages?

I have two tables, you can think of them of results of two models. I would like to compare them to a benchmark to evaluate which model is a better fit. What statistical technique do I need to do this ...
2
votes
1answer
202 views

Analysis method for count data with unequal sample sizes and categorical predictors?

I have a problem I've been going over and over for months to find the right statistical analysis method. I'm planning to execute the analysis in R, so any mention of appropriate packages is also ...