# posthocTGH

##### posthocTGH

This function is used by the 'oneway' function for oneway analysis of variance in case a user requests post-hoc tests using the Tukey or Games-Howell methods.

- Keywords
- utilities

##### Usage

```
posthocTGH(y, x, method=c("games-howell", "tukey"),
conf.level = 0.95, digits=2, p.adjust="none",
formatPvalue = TRUE)
```

##### Arguments

- y
y has to be a numeric vector.

- x
x has to be vector that either is a factor or can be converted into one.

- method
Which post-hoc tests to conduct. Valid values are "tukey" and "games-howell".

- conf.level
Confidence level of the confidence intervals.

- digits
The number of digits to show in the output.

- p.adjust
Any valid

`p.adjust`

method.- formatPvalue
Whether to format the p values according to APA standards (i.e. replace all values lower than .001 with '<.001'). This only applies to the printing of the object, not to the way the p values are stored in the object.

##### Value

A list of three elements:

List with input arguments

List of intermediate objects.

List with two objects 'tukey' and 'games.howell', containing the outcomes for the respective post-hoc tests.

##### Note

This function is based on a file that was once hosted at http://www.psych.yorku.ca/cribbie/6130/games_howell.R, but has been removed since. It was then adjusted for implementation in the `userfriendlyscience`

package. Jeffrey Baggett needed the confidence intervals, and so emailed them, after which his updated function was used. In the meantime, it appears Aaron Schlegel (https://rpubs.com/aaronsc32) independently developed a version with confidence intervals and posted it on RPubs at https://rpubs.com/aaronsc32/games-howell-test.

Also, for some reason, `p.adjust`

can be used to specify additional correction of *p* values. I'm not sure why I implemented this, but I'm not entirely sure it was a mistake either. Therefore, in `userfriendlyscience`

version 0.6-2, the default of this setting changed from `"holm"`

to `"none"`

(also see https://stats.stackexchange.com/questions/83941/games-howell-post-hoc-test-in-r).

##### Examples

```
# NOT RUN {
### Compute post-hoc statistics using the tukey method
posthocTGH(y=ChickWeight$weight, x=ChickWeight$Diet, method="tukey");
### Compute post-hoc statistics using the games-howell method
posthocTGH(y=ChickWeight$weight, x=ChickWeight$Diet);
# }
```

*Documentation reproduced from package userfriendlyscience, version 0.7.2, License: GPL (>= 3)*