sump function

Combine p-values using the sum of p (Edgington's) method

Combine \mjseqn p-values using the sum p method\loadmathjax

sump(p)
## S3 method for class 'sump'
print(x, ...)

Arguments

• p: A vector of significance values
• x: An object of class ‘sump’
• ...: Other arguments to be passed through

Details

Defined as \mjdeqn \frac (\sum _i=1^k p_i)^kk!

• k \choose 1\frac (\sum _i=1^k p_i - 1)^kk!

• k \choose 2\frac (\sum _i=1^k p_i - 2)^kk! ...((sum p) ^ k) / k! - (k-1)C(1) ((sum p - 1) ^ k) / k! + (k-2)C(2) ((sum p - 2) ^ k) / k! ...

where there are \mjseqn k studies and the series continues until the numerator becomes negative \insertCite edgington72ametap.

Some authors use a simpler version \mjdeqn \frac (\sum _i=1^k p_i)^kk!((sum p) ^ k) / k!

but this can be very conservative when \mjeqn \sum _i=1^k p_i > 1sum p > 1. There seems no particular need to use this method but it is returned as the value of conservativep

for use in checking published values.

The values of \mjseqn p_i should be such that \mjseqn 0\le p_i\le 1 and a warning is given if that is not true. A warning is given if, possibly as a result of removing illegal values, fewer than two values remain and the return values are set to NA. A warning is given when the internal calculations are likely to have been subject to numerical error and an alternative method should be used to check the result.

The plot method for class ‘metap’ calls plotp on the valid $p$-values.

Returns

An object of class ‘sump’ and ‘metap’ , a list with entries - p: The transformed sum of the \mjseqn p-values

• conservativep: See details

• validp: The input vector with illegal values removed

References

\insertAllCited

Author(s)

Michael Dewey

See Also

See also plotp

Examples

data(dat.metap)
edgington <- dat.metap$edgington
sump(edgington) # p = 0.097