All Questions
17 questions
61
votes
2
answers
77k
views
A/B tests: z-test vs t-test vs chi square vs fisher exact test
I'm trying to understand the reasoning by choosing a specific test approach when dealing with a simple A/B test - (i.e. two variations/groups with a binary respone (converted or not). As an example I ...
- 1,239
2
votes
2
answers
5k
views
Chi Square Test on small sample size
I have the following dataset and I am trying to run a Chi-square test between the control and pilot.
The only issue is that, for a Chi-Square test to return proper results, the sample size need to be ...
- 33
2
votes
1
answer
55
views
Statistical test to detect regional excess of observations compared to background observations
I have data on the protein position of genetic variants. I want to determine whether there is a region of the proteins with a significant excess of variants relative to controls.
Consider this ...
- 139
2
votes
1
answer
391
views
Which test to use: Chi-squared, Fisher's exact or some other?
I asked 200 survey participants the same sequence of eight multiple-choice questions with four answer options (A, B, C and D). Here are the results:
All A's: 58
All B's: 1
All C's: 2
All D's: 0
...
- 350
2
votes
1
answer
1k
views
How to interpret significant likelihood ratio and insignificant Chi-square tests?
To analyze frequencies in a 2x2 table, I ran a statistical test procedure using SPSS. It returned a p less than .05 for the likelihood Ratio but greater than .05 for Chi-Square and Fisher Exact Test (...
- 3,427
2
votes
0
answers
357
views
Statistical Significance of the "Cost per Conversion"
I am trying to optimize our AdWords ads and running some statistical tests. I use a chi-squared test and Fisher's exact test for conversion rate data; for example the click-through-rate (CTR) or the ...
- 21
1
vote
1
answer
2k
views
Fisher's exact test or chi-square test
I have a 2x4 table with nominal data (the columns are simply YES/NO, the rows are four categories)
...
- 9
1
vote
1
answer
29
views
1-sided vs 2-sided general M*N independence tests like Fisher exact or $\chi^2$ tests
What does the 1-sided vs 2-sided distinction mean for general $M \times N$ independence tests like Fisher exact, $\chi^2$ or $G$-test?
Which makes more sense?
What is the "negative" side in these ...
- 651
1
vote
0
answers
300
views
What statistical test could I use to compare categories of two data sets (for enrichment) with hugely different sample size?
I have some biological variant effect prediction data. This data can be split into categories based on the biological effect each variant has. I've turned this into two data sets: One is the "full" ...
- 11
1
vote
0
answers
1k
views
Fisher's exact / Chi-squared tests with repeated/dependent observations
I have a dataset (structure explained below) for which I want to perform some tests on 2x2-tables.
The data is generated from a (randomized) experiment, and structured as follows:
I have n subjects, ...
- 164
1
vote
1
answer
2k
views
What is the right usage in Fisher test in R
So I have data in form (in real data I have more rows, of course so this is just a sample)
...
- 67
1
vote
0
answers
549
views
Statistical analysis, what test should I use?
I have categorical data collected from a questionnaire.
It's mainly (Yes/No/Don't know) answers with the exception of the name of the software.
I'm doing a security analysis on different kinds of ...
- 11
0
votes
0
answers
65
views
Is Fisher's exact test good for this use?
I have a table that looks something like this:
group 1
group 2
group 3
group 4
region1
50
217
340
53
region2
32
23
36
42
:-------
:-------:
:-------:
:-------:
-------:
male
40
200
36
42
female
...
- 21
0
votes
0
answers
150
views
Should a contingency table be "symmetric"?
Im am running a fishers exact test on some data but im unsure of how the input contingency table should be formatted.
Option 1
...
- 1
0
votes
1
answer
128
views
Use of Chi-Square test of independence / Fisher Exact Test?
One of my research hypotheses is that individuals from Southeast Asia who are ethnically Chinese are more likely to experience racially motivated hate crimes than their counterparts from other ethnic ...
- 1
0
votes
0
answers
30
views
outage frequency analysis
I have several outage data points. Each outage has a time category (TP1 - TP3 - one could argue this is an ordinal variable) and week day.
The rolled up (artificial) frequencies data looks as follows:
...
- 2,225
0
votes
0
answers
35
views
Are the classic assumptions for Chi 2 test still valid?
For a 2*2 table, I want to use Chi 2 test
Are the classic assumptions (1# more than 80% of the contingency cells having expected values > 5, 2# no zero in the cells ) are still valid?
Is existence of ...
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