fisher's exact test

  1. J

    Is a Fisher's Exact test in a 7x9 contingency table feasible?

    Hello all, I have a question regarding the use of SPSS (i.e. its capability) to execute a Fisher's Exact test for large, sparse RxC contingency tables. I would like to test whether or not a certain correlation exist between my rows (diagnostic groups) and columns (laboratory tests) (see below)...
  2. C

    Post Hoc test for Fisher's exact test

    Hello everyone! I have performed a Fisher's exact test (5X3 tables) and I have found statistically significant differences in my groups. How can I find out in which groups significant differences were found? Is there any post hoc test I can perform? Thank you deeply in advance!
  3. N

    Calculating and Reporting Effect Size for Fisher's Exact Test?

    Hi everyone, I am writing a paper for publication. This is my first time doing a survey study, and also my first time working with categorical data (I, like many people unfortunately, have learned statistics bit by bit, as I have needed it in my research). The journal I am submitting to...
  4. M

    Fisher's exact test - two-tailed

    Hi guys, I performed a fisher's exact test on Genstat and got this result: One-tailed significance level 0.563 Mid-P value 0.371 Two-tailed significance level Two times one-tailed significance level 1.126 Mid-P value 0.741 Sum of all outcomes with Prob<=Observed 1.000 Mid-P value...
  5. S

    Approach to adjusting for multiple testing problem with multiple chi-square tests

    Hi, I work in a UK university. Each year finalist students take part in a National Student Survey responding to 30 questions on aspects of their experience on a five point likert scale, ranging from strongly agree to strongly disagree, and the convention is to report the percentage of...
  6. E

    Comparing groups/sites---need advice identifying variables and appropriate tests

    Hi, thank you for reading this and your potential input. This is a research study. I examined the prevalence of parasites in one insect species in an island ecosytem. Insects were collected from: Island 1: 3 sites (all very different elevations) Island 2: 2 sites (similar elevation)...
  7. S

    validity of data arrangement in a 2x2 table for fishers exact test.

    Hi, I have two conditions (A and B) to which the subjects has been exposed to. There are two responses to those conditions yes or no. I can arrange the data in a 2x2 table in two different ways: The P value for fishers exact test is 0.0028. This table for fishers exact test...
  8. L

    Is a McNemar's test appropriate in this setting?

    I wrote a scientific paper on the use of two different surgical techniques on two organs in the same subject: technique A for one ovary and technique B for the contralateral ovary on 51 subjects. Cure rates for technique A was 48 out of 51, and 50 out of 51 for technique B. To evaluate these...
  9. M

    Question about Fisher's Exact Test

    Hi everyone- new to posting here. I am wondering if I can get some feedback on simple code for a Fisher's test, as I am pretty new to R. I am inputting a 3x2 table, may be easier just to see the table/code below. The output I get looks pretty different to me than the output I got for a 2x2...
  10. N

    Analysis and Post-hoc for Ordinal Variables

    My main questions are; 1) For a Chi goodness of fit test, which effect size do you use? I am being told Cramer's V, Phi, Omega and W! (There seem to be a lot more answers for a Chi association test, but not for a Chi goodness of fit) 2) Can you use an Odds Ratio with a Chi goodness of fit...
  11. L

    t-tests vs chi square test/Fisher's exact test

    Hello forum friends! So I have been using excel to compare if two groups are statistically significantly different. My null Hypothesis is that these two groups are the same (or that there is no difference between groups). When comparing my Hispanic population vs non-Hispanic population...
  12. P

    Address whether one overlap is significantly bigger that of another related overlap

    I could really use a hit as to which statistical test I need to use to address the following problem: I have three different species: A, B and C. I have compared the quantitative overlap (i.e. something that was measured and counted in all 3 species) of Species A and B, respectively, with...
  13. N

    how to test 2x2 table with an one empty cell in admission patients?

    I am a clinician working for a community based hospital. A few days ago, my fellow doctor asked me if I could give some advice for her data. She was working on cross-sectional study in which she investigated the bad effect of high glucose level to the short term outcomes after certain...
  14. J

    (categorical data - small sample) Appropriate test(s)?

    Greetings! I have a small sample (11 responses) of categorical data. I want to compare a binary response (near vs. far) to a nominal response (disease 1,2,3,4,etc.), and see if there is any dependence. Chi-square has given me a poor response with expected cell counts below 1. I looked at...
  15. A

    is there a Fisher's exact test (or similar) for continuous data?

    I have a simple statistical problem, but am having a hard time identifying a good solution. I am interested in testing to see if an independent factor (length of time interval between 2 different 1 choice tests) influences the association time (a continuous variable) between two options (fast...
  16. K

    Alternatives to logistic regression when the number of cases is low

    Hi All I got involved in my first foray into logistic regression, but have come to realize that I probably can't use it. Let me tell you about my data. I am investigating the consumption of 3 different insect pests by bats in an agricultural area. The response variable is binary for each...
  17. T

    Chi-square, expected counts & Fischer exact test

    Sitting here with a stat book and some questions are popping up. Chi-square assumes that expected counts are greater than 5. However, in larger tables it is allowed to have up to 20% of expected counts less than 5. What is this 20% of? Is it of the cells in the matrix. For example, in a 2x4...
  18. N

    Likert: Fisher's exact OR Kruskal-Wallis?

    Hi, I've got a survey with 50 responses, and want to test for difference between three subgroups, and strength of association. I'm not happy to treat data as continuous. But I'm not sure whether I should use Kruskal-Wallis to compare rating scores between groups, or Fisher's Exact Test...
  19. A

    Fisher's exact test, Hypergeometric distribution

    Hi, I need some help with Fisher's exact test and the hypergeometric distribution My data consists of: 500 mutations - that I want to score as either damaging or benign 500 population allele frequencies (AF) - extracted, for each mutation, from a set of 10 000 controls For each...