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Questions tagged [contingency-tables]

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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Lower threshold for Sequential Probability Ratio Test on Contingency Table testing

For testing whether a die is fair, we have the log likelihood ratio: $$ \Lambda = \frac{1}{2} \sum_{i} \mathrm{observed}_i \log\left(\frac{\mathrm{observed}_i}{\mathrm{expected}_i}\right). $$ Suppose ...
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Were two 2x2 tables drawn from the same population?

How might one test the null hypothesis that two 2x2 tables (of frequencies) were drawn from the same population? More specifically, I have two 2x2 samples of unequal sample size. I would like to test ...
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Estimate subgroup sizes with a a given OR including CI and total sample sizes

We are doing a meta-analysis using OR as the effect size, but on a limited number of trials. The data is a bit messy and some numbers are missing - at least for our purposes. I was wondering if there ...
umrpedrod's user avatar
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Am I using the appropriate statistical comparison tests & applying them correctly to my qualitative coded data?

I am trying to determine if I am using the correct statistical tests in making comparisons & finding out if there are any statistically significant shifts of student attitudes. I have three open ...
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Can Cramér's V or contingency coefficient be used if chi-squared assumptions are not met?

I am testing for the independence of a specific set of variables with respect to a common event. Despite having a fairly decent sample size (n=236), the event I am testing for is relatively rare (2% ...
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Performing "exact" G-tests in R with contingency table samples using `r2dtable` [closed]

I am interested in performing the "exact" versions of G-tests of independence in R with nonparametric table enumeration after having been told that this could help with achieving more ...
potpie's user avatar
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Is there alternative to Fisher's Exact Test for 6X2 contingency table with the hypothesis of "less than"?

I have a table of contingency which is 6X2 and in my case, it is not an option to "convert" it in a 2X2 table. Also, I need to be able to use the hypothesis of "less than" and &...
Marlom's user avatar
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Chi square test of independence with year as a categorical variable?

I suppose that this is a very simple question, and I have just now recently started doing stats. I am working on a dataset with count data relating to discontinuation/continuation of a specific ...
Mukilan S C's user avatar
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Testing for Association in RxC Contingency Tables with 1 Ordinal Variable

I'm currently trying to analyze data similar to the following example: Suppose I have count data from a survey of US States (~10) relating to their population's feelings about how their current state ...
Rubberduckquack's user avatar
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Statistical significance for difference in mean proportions when comparing groups

I may not have described my problem precisely, but I hope I can illustrate it with the following example. Suppose that I have $m$ contingency tables: Col 1 Col 2 Total Row 1 $a_i$ $b_i$ $a_i+b_i$ ...
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Performing a Fisher test when the odds of the events not occurring are known to be very low when compared to the events occurring

Let's say I have a contingency table like this: ...
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Logistic regression 2 x 2 table equivalent for continuous covariate

I am giving a talk about logistic regression and I am trying to go back to basics with explaining what odds are in the context of model estimation using logodds and calculation of probabilities which ...
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Finding the smallest possible sample size of a 2x7 contingency table, given row-wise proportions and relation between row marginal counts

NB: this is not about power analysis. Consider the following table, which has the following row-wise proportions: cat_1 cat_2 cat_3 cat_4 cat_5 cat_6 cat_7 A 0.3222449 0.302041 0.208163 0.089796 0....
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Required sample size for exact McNemar test and for phi coefficient (power analysis)

I aim to establish the required sample size for my study. In the main analyses, which are conducted to test my hypotheses, I am investigating two 2x2 tables. Specifically, I plan to perform an exact ...
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3 answers
393 views

Is Fisher's exact the right statistical analysis to be using?

I am conducting a service evaluation study and want to assess the association between referral type (self vs. clinician) and gender (Female v Male v Other). Therefore my contingency table is 2x3. I ...
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How to test if occurrence distributions are equal with dependent variables

Description of the experiment Each experiment is a performance done by an artist/athlete, and these are independent. I have $k=4$ judges labelled $J\in \{1,2,3,4\}$ that can classify a performance ...
JonATusso's user avatar
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Barnard's unconditional test gives different results when switching rows and columns?

I'm really new to statistical analysis, and I've been playing around with exact tests for 2x2 contingency tables. I've noticed that for the Barnard test (implementation with ...
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Normal Approximation in testing for association in a 2x2 contingency table

Suppose we have a 2x2 contingency table with binary RVs $X, Y$ and we want to test for independence. Let $n$ be the total amount of measurements. Let $n_{11}$ be the number of occurrences of both $X = ...
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Significance in 3x3 crosstab including low values and high N

I am conducting a study of 126 organizations. Each organization has one or more registered domain names. Each domain name needs to conform with specific cybersecurity requirements. Some ...
possum's user avatar
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Statistical significance tests for contingency tables in panel survey

I'm having a bit of trouble choosing what statistical test to pick. Hopefully you can advise. I have a panel survey in two waves (with almost all the same respondents retained from wave 1 to wave 2. I ...
Reuben Long's user avatar
3 votes
2 answers
134 views

Chi-Square test - respondents may be assigned to multiple categories?

I am referring to this example: http://www.sthda.com/english/wiki/chi-square-test-of-independence-in-r The data used are frequencies for household tasks: Wife Alternating Husband Jointly Laundry 156 ...
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What method should I use if I want to estimate proportions in a 2xc contingency table (where c >2)?

This is a theoretical question, but it's been in the back of my head for a while now. Let's say I have two groups A and B, and I already know that they differ relative to their distribution on a ...
Daniela's user avatar
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Statistical test for 3x2 contingency table, with cases:controls matched 1:5 (i.e. non-independent)

I am examining a cohort of cases against controls, matched at a 1:5 ratio (on sex, birth year, and residency/postal code at time of diagnosis). Education level Cases (n=206) Controls (n=957) p-value ...
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Two-sample statistical significance test taking into account group membership (proportions) and numeric comparison

Say I have two samples of observations, S1 and S2, which can be of unequal sizes. For each observation, I have two variables: G (a categorical group assignment, say it is binary with values A/B), and ...
Sam A.'s user avatar
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Chi-squared test with more than two variables, or should I run a different test?

I am looking at whether certain animals or categories of animals are more likely to use human-made trails than natural trails. We used camera traps and recorded for every case which animal it was, ...
Manon Obdeijn's user avatar
8 votes
2 answers
531 views

Infinite upper confidence interval using Fisher exact test in R

I am having trouble interpreting the upper confidence interval for the odds ratio (OR) after executing Fisher's exact test in R. I have the following contingency table which contains the response ...
Samuel Leal's user avatar
3 votes
1 answer
392 views

Standardised residuals in contingency tables and statistically significant result

I have the following contingency table that results in statistically significant result of Pearson's $\chi^2$ Test for Count Data. I've computed Pearson residuals that should have the same properties ...
Lstat's user avatar
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11 views

Enrichment of positive cases within paired data

I have analyzed 47 cancer samples from tissue and blood. In the tissue 40 are positive for a virus and in the blood 8 are positive for the virus Importantly, these 8 are the same patients that are ...
user2300940's user avatar
2 votes
1 answer
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Compare two contingency tables with the same structure

I want to compare two contingency tables A and B with the same structure (same columns and rows). My first idea was to use chi squared distance $\sum_{i=1}^{p}{\frac{(O_i-E_i)^2}{E_i}}$. But, some ...
Mohamed Gueye's user avatar
2 votes
2 answers
90 views

Comparing two association matrices (contingency tables)

I am looking for a significance test to compare between two association matrices (contingency tables) - preferably to test whether the odds ratio is the same. I have looked at some questions here but ...
anna6931's user avatar
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2 votes
2 answers
85 views

Bayesian inference based on a 3$\times$3 contingency table

How do I make inferences about population parameters based on a 3$\times$3 table of observations? In "Bernoulli's Fallacy", Aubrey Clayton provides this (Table 5.8). Democrat Republican ...
Mkanders's user avatar
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How can I update a contingency table based on evidence?

I have a series of contingency tables that are my population benchmarks and survey data. Practically speaking, we know the population benchmarks are largely, but not entirely, accurate; there are some ...
stat_is_quo's user avatar
1 vote
1 answer
105 views

How to calculate the p-value of a log-odds ratio, given that the variance depends on the observed frequencies?

I am a bit confused about how people calculate p-value when calculating odds-ratios. The log-odds ratio (LOR) for a contingency table with two entries is $L = \log \frac{p_{1}}{p_{0}}$ and has an ...
Abelaer's user avatar
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1 answer
211 views

Test to compare multiple contingency tables

I have three contingency tables with the variables month and region that contain the frequency of the sighting of a particular bird. Additionally, the tables differ only by counting frequencies from ...
jjohn102's user avatar
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1 answer
137 views

Does Cochrane-Armitage test require an obvious trend in contingency table?

I'm trying to determine whether it's appropriate to use the Cochrane-Armitage trend test on this set of data? I don't have any specific hypotheses I need to investigate, just to choose an appropriate ...
Manny Ma's user avatar
1 vote
0 answers
56 views

Inference for Contingency tables [closed]

Assume two paired binary vectors, $v^A,v^B$. We can easily construct a contingency table looking like: $v^A_i=1$ $v^A_i=0$ Totals $v^B_i=1$ $a$ $b$ $a+b$ $v^B_i=0$ $c$ $d$ $c+d$ Totals $a+c$ $b+d$ ...
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margins=True option in pd.crosstab influences the outcome of chi2_contingency test. Why?

I understand what the margins=True option in pd.crosstab does, but I don't understand why it would influence the outcome of the chi2_contingency. Here an example: ...
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Relative Risk and Odd ratio for N x N x N table

I am trying to calculate RR for case where I have N x N x N table. First N is City (20 cities) second N is Age group (5 groups) and third one is Industry (4 ...
guest-x1's user avatar
3 votes
1 answer
62 views

I have an issue summarising highly skewed data in a table

I have a numerical ordinal dataset (eg. 1-10) that's very highly skewed, with >90% of the values at 10. How can I best summarise this in a table? The median/IQR gives '10 (10, 10)' (which doesn't ...
Harry's user avatar
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3 votes
0 answers
380 views

The asymptotic distribution of a Pearson Chi-Square test statistic (test for independence)

There are many different Pearson Chi-Square tests. The test statistics are always a sum of scaled and squared deviations. Some are written as a single sum, and some are written as a double sum (the ...
Taylor's user avatar
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2 votes
1 answer
126 views

Making sense of a reviewer's "30 observed counts minimum per cell" requirement on a contingency table

I'm perplexed by the comment of a reviewer, who has taken issue with the sample size from a study I conducted. He says, relatively to the 2X2 contingency table below and a (significant) 2-sample test ...
J-J-J's user avatar
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1 vote
1 answer
147 views

What will happen to my results if I use Fisher's exact test with unfixed marginal totals?

I've been trying to get my head around the controversy that surrounds Fisher's exact test. I often use the test in the something like the following way: A survey asks respondents two questions: "...
David Lovell's user avatar
3 votes
0 answers
250 views

Alternatives to logistic regression if there are zero counts

I have three variables (let's call them $A$, class (both binary) and age (numerical)), and I want to test if there is a difference in the presence of A between the two classes, with age as a potential ...
user36196's user avatar
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Statistical test for odds ratio when 1. N is large and not meaningful; 2. replicates are present

I'm investigating the co-occurrence of 2 types of events (var1 and var2). The hypothesis is that ...
Jerry Fan's user avatar
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0 answers
45 views

No theoretical frequency should be less than 5 [duplicate]

Why does the theoretical frequency in chi-square distribution should not be less than 5? What's the concept behind pooling the preceding and succeeding frequency to make pooled frequency more than 5?
Aman's user avatar
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1 answer
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Calculate correlation of nominal and ordinal variables and hypothesis test in r

I would like to statistically analyze three variables. One variable is "consortium mostly academic" (nominal, dichotomous), the second variable is "evaluation method" (nominal, non-...
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How to apply Bayes' theorem on a contingency in which the sampled distribution differs drastically from the entire population?

Summary: How can I calculate my probability of being truly positive based on a contingency table that has a completely different distribution than the total population? I was recently confronted with ...
jotheta's user avatar
1 vote
1 answer
440 views

Chi-square test for two vectors with very similar values

I have two vectors with two levels: vector 1:...
HAOYANG MI's user avatar
1 vote
1 answer
156 views

Contingency analysis of a 3x3 table via Chi2, log-linear and Poisson GLM - how to interpret this result?

I have a dataset describing age of wine in 3 classes of quality. ...
CroissSant's user avatar
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1 answer
201 views

Chi-squared test for equality of proportions

This question is question 12 from Problems 10.3 from Rohatgi's An Introduction to Probability and Statistics. Of 25 income tax returns audited in a small town, 10 were from low and middle income ...
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