.crawford.CI {singlecase} | R Documentation |
.crawford.CI
is an internal function that computes 95% confidence intervals around the rarity of a score (Crawford & Garthwaite, 2002). These confidence intervals are based on non-central $t$-distributions.
.crawford.CI(c,n)
c |
test statistics |
n |
number of control subjects |
c
is an observation from a non-central $t$-distribution on n
- 1 degrees of freedom. Confidence intervals are based on two values of the non-centrality parameter of non-central $t$-distribution, such that the resulting non-central $t$-distribution has $c sqrt{n}$ as its $100 α / 2 $ percentile (value 1) or as its $100 (1-α/2)$ (value 2) (for details, see Crawford & Garthwaite, 2002). The purpose of the .crawford.CI
function is to find those values.
2.5% |
Lower bound of the confidence interval. |
97.5% |
Upper bound of the confidence interval. |
Matthieu Dubois. matthdub@gmail.com, http://www.code.ucl.ac.be/MatthieuDubois/r_code.html
Crawford, J. R., & Garthwaite, P. H. (2002). Investigation of the single case in neuropsychology: Confidence limits on the abnormality of test scores and test score differences. Neuropsychologia, 40(8), 1196–208.
crawford.t.test
, crawford.diff.test