`R/BSDA-package.R`

`German.Rd`

Data for Exercise 7.60

`German`

A data frame/tibble with ten observations on three variables

- student
a character variable indicating student number

- when
a character variable with values

`Before`

and`After`

to indicate when the student received experimental instruction in German- errors
the number of errors in copying a German passage

Kitchens, L. J. (2003) *Basic Statistics and Data Analysis*.
Pacific Grove, CA: Brooks/Cole, a division of Thomson Learning.

```
t.test(errors ~ when, data = German, paired = TRUE)
#>
#> Paired t-test
#>
#> data: errors by when
#> t = -3.638, df = 9, p-value = 0.005417
#> alternative hypothesis: true difference in means is not equal to 0
#> 95 percent confidence interval:
#> -4.0545188 -0.9454812
#> sample estimates:
#> mean of the differences
#> -2.5
#>
wilcox.test(errors ~ when, data = German)
#> Warning: cannot compute exact p-value with ties
#>
#> Wilcoxon rank sum test with continuity correction
#>
#> data: errors by when
#> W = 26, p-value = 0.0739
#> alternative hypothesis: true location shift is not equal to 0
#>
if (FALSE) {
T8 <- tidyr::spread(German, when, errors) %>%
mutate(di = After - Before, adi = abs(di), rk = rank(adi), srk = sign(di)*rk)
T8
qqnorm(T8$di)
qqline(T8$di)
t.test(T8$srk)
}
```