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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1answer
31 views

Can I get an Odds Ratio (or other effect size) from two proportions and a p-value?

I am conducting a meta analysis that is comparing dichotomous outcomes for two groups. So for each study, I have the proportion of the outcome for both groups and the sample size of each group, and I ...
0
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0answers
48 views

How to interpret conditional odds ratios from a three-way contingency table?

I am trying to understand how to correctly interpret the estimated conditional odds ratios from a loglinear model on a three-way contingency table. This is an example from Agresti 2013 (p. 346, ...
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0answers
8 views

What is the null model for a four-way contingency table?

I'm working through this tutorial on the Titanic data in R, a four-way contingency table, and I'm unclear as to what is the NULL ...
4
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2answers
45 views

How to interpret a two-dimensional contingency table?

I am trying to understand how to interpret log-linear models for contingency tables, fitted by way of Poisson GLMs. Consider this example from CAR (Fox and Weisberg, 2011, p. 252). ...
0
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1answer
19 views

solution for large contingency table

I have performed logistic regression using SPSS on my data with a dichotomous variable as the dependent variable with three independent variables and three covariates (they are mostly categorical) ...
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0answers
14 views

goodness of fit vs independence test in finite population case

I have a finite population frame. Around 80% of the frame members have e-mail addresses, and a survey was sent via e-mail to those people. Roughly 20% of those to whom e-mails were sent replied to the ...
2
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1answer
31 views

How does Google Analytics calculate “Probability of Outperforming Original”?

Here's an example content experiment in Google Analytics. Can anyone explain how to calculate that there's a 98.7% "Probability of Outperforming the Original"?
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0answers
17 views

Contingency testing in geographic data with the issue of independence?

How can I test contingency between two variables in geographic data with the issue of independence? I have a column of fire frequency and a column of vegetation change but do not think a simple chi ...
3
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2answers
64 views

R: how to interpret mosaic and association plots

I'm using the mosaic and assoc functions in the library vcd. My mosaic plot is as follows: ...
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0answers
6 views

Finding the differences for nominal data when each participant contributes to more than one cell in the frequency table?

Finding the differences for nominal data when each participant contributes to more than one cell in the frequency table. The point is that I don't have paired nominal data as it is in repeated ...
1
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0answers
14 views

enumerating patterns in a set of contingency tables

I have a set of 3X3 contingency tables and want to identify the distribution of the patterns by comparing their expected and observed number of samples in each cell using a right statistical test. For ...
5
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1answer
39 views

Cramer's $\phi $ for three-way contingency tables

Can Cramer's $\phi $ be determined for three-way contingency tables? I know how to calculate the expected values, chi squared, and how Cramer's $\phi $ works with two-way contingency tables. However, ...
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0answers
26 views

Which exact test should I use for my data?

I'm very new to statistical analysis, and I am wondering if I am paying too much attention to unimportant questions. My data consists of about 40 cases involving a particular kind of lawsuit. After ...
3
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2answers
63 views

$\chi^2 $ of multidimensional data

I want to test if two observations of nominal data accord to the same distribution. I am using the chi squared statistics to perform a chi squared homogeneity test and normalize the result with ...
3
votes
1answer
90 views

How to interpret the residual colors on a mosaic plot?

This is a mosaic plot of contingency table dataset HairEyeColor described here. How do I interpret the colors representing residuals? What is the difference ...
8
votes
4answers
137 views

Which is the best visualization for contingency tables?

Which is best plot, from statistical standpoint, to show a contingency table, which is typically being analyzed by chi-square test? Is it a dodged barplot, stacked barplot, heatmap, contour plot, ...
7
votes
2answers
203 views

Fisher exact test on paired data

Given $40$ cases with lung cancer and $40$ matched controls (without lung cancer) (matching based on age, sex, etc.). To try to find evidence between the effect of smoking on lung cancer, I used ...
3
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1answer
45 views

Determining $\chi^2 $ for Cramer's $\phi $

I intend to determine Cramer's $\phi$ for two contingency tables of the following form: ...
2
votes
1answer
84 views

I don't understand Chi squared

I think of the contingency table test. In all textbooks I've seen, the test statistic is calculated as the sum of $(O-E)^2/E$ over all cells. But the degree of freedom is not the number of all cells. ...
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0answers
45 views

How important is the arrangement of data in a 2x2 contingency table for fishers exact test?

I am comparing expression of different genes involved in the same metabolic reaction of basil to two different conditions, exposure to cold Vs Infra-red light. I am in the process of analysing RNA seq ...
1
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1answer
37 views

Is it possible to compute the mean/median of an variable by a contingency table?

A contingency table contains the frequencies of two discretized variables. To be more specific, the discretization is done by splitting the spectrum of a signal into equal width intervals. Is it then ...
1
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1answer
65 views

Using contingency tables for testing multiple dependencies

I know that I can determine the correlation / association / dependency between two variables (X= smoker, and Y=cancer) using chi-squared with a 2x2 contingency table: ...
2
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1answer
40 views

Help with analyzing/planning a physical experiment — regression

This is a real experiment about to be performed Batches of samples will be prepared. A Striker will be used to see if a reaction will occur. For example: 20 drops might be performed, and number of ...
2
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0answers
31 views

Test for independence in 3x2x2 table with small expected cell values

I have three unordered categorical variables. I have made a 3x2x2 table, but I'm uncertain of how to test for independence. The usual manner is a chi-squared statistic, but I think this is ...
2
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0answers
19 views

rxc contingency tables

Hi I am trying to analyse categorical data and to construct a contingency table based on a survey data. In the contingency table, there were 5 ordinal ratings(blank, unacceptable, below average, ...
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0answers
32 views
4
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1answer
260 views

Why does Pearson's chi-squared test detect differences that the GLM model fails to detect?

How can I interpret the following result? I have 4 groups with around 300 observations each: ...
0
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0answers
51 views

Disproportioned contingency table

I have a database of clients, some of which have gotten a special pill - and the rest have not gotten the special pill. Afterwards I measure if the clients starts exercising. My contingency table ...
2
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1answer
65 views

Contingency table for gene groups

I have two lists of genes as follows: DEList has 282 gene names AllList has 32805 gene names ...
2
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0answers
34 views

A generalized measure of relative enrichment for elements of a contingency table [closed]

Problem: If given a matrix of counts of observations between some features (F) f1-f4 (e.g., GO terms or pathways, in rows) and genes / proteins (P) p1-p3 (in columns), what would be: A good way to ...
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0answers
14 views

Help interpreting this result based on conditioning on gender -Contigency Tables

The problem i'm having is how to interpret the results I got. For part a) I got that the abortion laws are independent of generation where I used a $\chi^2$ test. For part b) I got that the the age ...
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0answers
9 views

Regression Model for Matched Continency Tables Coefficient Interpretation

Sorry to insist. A number of questions in the same direction (coefficient interpretation) by different contributors, never answered. ...
2
votes
1answer
32 views

Regression Model for Binary Matched or Paired Contingency Table Results

This is a follow-up question on a prior thread about the same setup as follows: We have two "Methods" ("A" and "B") to diagnose a medical condition. We are not trying to determine which one is better ...
0
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0answers
93 views

Fisher's exact test for 3x5 contingency table in R with post-hoc? Consistently with using Fisher or Chi-squared?

I'm struggling with some (relatively simple) stats questions for some work I'm doing in R, and can't seem to find answers online... I have a factorial response variable of habitat type of a species ...
1
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0answers
23 views

Correlated Proportions shown in a Mosaic Plot. What is the fitted model that generates residuals?

I have a 2-by-2 table of correlated proportions where I am plotting the positivity of two diagnostic methods applied on a sample of 216 individuals: ...
1
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0answers
52 views

Dimension reduction for discrete qualitative and aggregated variables

I know about PCA for multiple dimensions of continuous features but here is a problem I have some trouble to find a method for. I don't have a list of individual countries but rather a discrete ...
2
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0answers
37 views

Fisher's Exact Test for 2x3 tables

I'm writing my dissertation and I need to cite a source to support using the FET for 2x3 tables. Does anyone knows of a source that can be cited? Thank you!
2
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1answer
41 views

Is this a valid use of “positive predictive value”?

So here's your typical table for evaluating the performance of a diagnostic test: Gold standard result ...
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0answers
42 views

Calculating Odds Ratios for a 3 x 3 Table

How would I go about calculating the Odds Ratios (measures of association) for a 3 x 3 Table
4
votes
2answers
170 views

Is the chi-squared test appropriate with many small counts in a 5x2 table?

I have two sample populations, A, and B, which are independent. ...
0
votes
0answers
127 views

SPSS chi-square output interpretation

Sorry for the dumb question, I need some help with the interpretation of the spss chi-square test outcome. Basically I have two variables: the first one is a binary variable which takes value 1 if a ...
5
votes
2answers
184 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?
2
votes
1answer
48 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
37 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
votes
1answer
205 views

Computing the power of Fisher's exact test in R

Suppose that I have the following 3 x 3 contingency table: ...
2
votes
0answers
33 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 ...
1
vote
1answer
1k 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 ...
9
votes
2answers
398 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
votes
1answer
62 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
votes
0answers
85 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 ...