metap (version 0.8)

logitp: Combine p values using logit method

Description

Combine \(p\) values using logit method

Usage

logitp(p)
# S3 method for logitp
print(x, ...)

Arguments

p

A vector of \(p\) values

x

An object of class ‘logitp’

...

Other arguments to be passed through

Value

An object of class ‘logitp’ and ‘metap’, a list with entries

t

Value of Student's \(t\)

df

Associated degrees of freedom

p

Associated \(p\)-value

validp

The input vector with illegal values removed

Details

Defined as $$t = - \frac{\sum \log\frac{p}{1 - p}}{C}$$ where $$C = \sqrt\frac{k \pi^2 (5 k + 2)}{3(5 k + 4)}$$ and \(k\) is the number of studies.

The values of \(p\) should be such that \(0<p<1\). A warning is issued if this means that studies are omitted and an error results if as a result fewer than two studies remain.

The plot method for class ‘metap’ calls schweder on the valid \(p\)-values

References

Becker, B J. Combining significance levels. In Cooper, H and Hedges, L V, editors A handbook of research synthesis, chapter 15, pages 215--230. Russell Sage, New York, 1994.

See Also

See also schweder

Examples

# NOT RUN {
data(teachexpect)
logitp(teachexpect) # t = 2.763, df = 99, p = 0.0034, from Becker
data(beckerp)
logitp(beckerp) # t = 1.62, df = 29, NS, from Becker
data(validity)
logitp(validity) # t = 9.521, df = 104, p = 3.89 * 10^{-16}
# }