# tadaa_pairwise_t

##### Extended Pairwise t-Tests

This is an extension of stats::pairwise.t.test that's meant to deal with interactions our of the box, while also performing pairwise tests for the primary terms. The output of the function is modeled after stats::TukeyHSD, unfortunately without confidence intervals or test statistic though.

##### Usage

```
tadaa_pairwise_t(data, response, group1, group2 = NULL, p.adjust = "bonf",
paired = FALSE, pool.sd = !paired, alternative = "two.sided",
print = "df")
```

##### Arguments

- data
A

`data.frame`

containing the variables.- response
The response variable, i.e. the dependent numeric vector.

- group1
The grouping variables, typically a

`factor`

.- group2
(Optional) second grouping variable.

- p.adjust
The p-adjustment method, see stats::p.adjust.methods, passed to stats::pairwise.t.test. Additionally,

`sidak`

is supported as a method, which is not the case with stats::p.adjust, as is`sidakSD`

for the Sidak step-down procedure.- paired
Defaults to

`FALSE`

, also passed to stats::pairwise.t.test.- pool.sd
Defaults to the inverse of

`paired`

, passed to stats::pairwise.t.test.- alternative
Defaults to

`two.sided`

, also passed to stats::pairwise.t.test.Print method, defaults to

`df`

for`data.frame`

output, otherwise passed to pixiedust::sprinkle_print_method.

##### Value

A `data.frame`

with columns `term`

, `comparison`

and `adj.p.value`

.

##### Note

The adjustment method is applied within each `term`

, meaning that the number of
pairwise t-tests counted for the adjustment is only equal to the number of rows
per `term`

of the output.
The additional Sidak adjustment method uses the following method:
`p_adj <- 1 - pbinom(q = 0, size = length(p_values), prob = p_values)`

And is sometimes preferred over Bonferroni.
The Sidak-like (1987) step-down procedure (`sidakSD`

) is an improvement
over the Holm's (1979) step-down procedure.

##### References

https://stats.stackexchange.com/questions/20825/sidak-or-bonferroni

https://rdrr.io/rforge/mutoss/man/SidakSD.html

##### See Also

`tadaa_pairwise_tukey()`

, `tadaa_pairwise_gh()`

Other Tadaa-functions: `tadaa_aov`

,
`tadaa_chisq`

, `tadaa_kruskal`

,
`tadaa_levene`

, `tadaa_nom`

,
`tadaa_normtest`

,
`tadaa_one_sample`

, `tadaa_ord`

,
`tadaa_pairwise_gh`

,
`tadaa_pairwise_tukey`

,
`tadaa_t.test`

, `tadaa_wilcoxon`

##### Examples

```
# NOT RUN {
tadaa_pairwise_t(ngo, deutsch, jahrgang, geschl, p.adjust = "none", print = "console")
tadaa_pairwise_t(ngo, deutsch, jahrgang, geschl, p.adjust = "bonf", print = "console")
tadaa_pairwise_t(ngo, deutsch, jahrgang, geschl, p.adjust = "sidak", print = "console")
# }
```

*Documentation reproduced from package tadaatoolbox, version 0.16.0, License: MIT + file LICENSE*