Cross Validated Asked on November 29, 2020

I’ve performed a two-sided Fisher’s exact test on the following data, and the results include Infinity for the upper confidence interval and odds ratio. Are these results erroneous, and if not how do I interpret them? I’ve done a bunch of searching and reading, but have a hard time wrapping my head around why the infinite results occur. When I add 0.5 to each cell I still obtain infinity.

Data:

```
Fisher's Exact Test for Count Data
p-value = 0.002719
alternative hypothesis: true odds ratio is not equal to 1
95 percent confidence interval:
2.196186 Inf
sample estimates:
odds ratio
Inf
```

Any insight is greatly appreciated

The issue is not the results of Fisher's test - as Frank Harrell pointed out, you are dividing by 0.

The results are fine, I think it's the question that needs work. That is, rather than ask about the odds ratio, you might want to ask about something else, like a test of proportions. This topic has an extensive literature.

Are the results variable? Well, not from *this* sample, but you might, of course, get different values in a different sample. You might get a 1 instead of a 0 for the upper right cell.

Answered by Peter Flom on November 29, 2020

Knowing the formula to calculate the odds ratio will tell you why you get an 'Inf' value. Basically, you're dividing by 0. There's a lot of documentation available on the net (here you can find an example).

As to adding 0.5 to all values, the R implementation of the Fisher's Test only works with nonnegative integers. Even if you add 0.5, the values will be rounded to integers (so 0.5 will become 0).

Answered by Daniel A on November 29, 2020

1 Asked on February 18, 2021 by forlooper

1 Asked on February 18, 2021 by borut-flis

0 Asked on February 17, 2021 by kaaren0111

1 Asked on February 17, 2021 by xxtensionxx

bayesian conjugate prior exponential family prior self study

1 Asked on February 17, 2021 by aflatoun

1 Asked on February 17, 2021 by exlo

1 Asked on February 17, 2021

1 Asked on February 16, 2021 by xe-m

2 Asked on February 16, 2021 by user1272262

0 Asked on February 16, 2021 by davud-mursalov

1 Asked on February 16, 2021 by johnny5ish

0 Asked on February 15, 2021 by wilmer-e-henao

2 Asked on February 15, 2021 by pterojacktyl

0 Asked on February 14, 2021 by ahmet-turul-bayrak

0 Asked on February 14, 2021 by gracetam

1 Asked on February 14, 2021

0 Asked on February 14, 2021 by fouzia-farooq

4 Asked on February 14, 2021

mathematical statistics statistical significance zero inflation

1 Asked on February 14, 2021 by fuca26

4 Asked on February 14, 2021 by gpuguy

Get help from others!

Recent Questions

- How Do I Get The Ifruit App Off Of Gta 5 / Grand Theft Auto 5
- Iv’e designed a space elevator using a series of lasers. do you know anybody i could submit the designs too that could manufacture the concept and put it to use
- Need help finding a book. Female OP protagonist, magic
- Why is the WWF pending games (“Your turn”) area replaced w/ a column of “Bonus & Reward”gift boxes?
- Does Google Analytics track 404 page responses as valid page views?

Recent Answers

- Joshua Engel on Why fry rice before boiling?
- Peter Machado on Why fry rice before boiling?
- Jon Church on Why fry rice before boiling?
- haakon.io on Why fry rice before boiling?
- Lex on Does Google Analytics track 404 page responses as valid page views?

© 2022 AnswerBun.com. All rights reserved. Sites we Love: PCI Database, MenuIva, UKBizDB, Menu Kuliner, Sharing RPP, SolveDir