pcrit: Calculate pcrit

In ianhussey/ethicalpeeking: Calculate paugmented, pcrit, and pactual.

Description

This function calculates pcrit, a statistic discussed in Sagarin, Ambler, and Lee's (2014, Perspectives on Psychological Science, 9, 293-304) "An Ethical Approach to Peeking at Data".

Usage

pcrit(ns, pmax = 1, pdesired = 0.05, slices = 1000, tails = 2)

Arguments

ns	refers to a vector of sample sizes that indicate the initial number of participants run (N1) followed by the number of participants in the first round of augmentation (N2), the number of participants in the second round of augmentation (N3), etc.
pmax	refers to the maximum p-value in the data collected thusfar such that the researcher would augment the sample with additional participants.
pdesired	refers to the desired Type I error rate (typically .05).
slices	refers to the number of slices to divide the probability distribution (higher numbers of slices will make the calculations slower but more precise).
tails	refers to whether the tests are one- or two-tailed.

Examples

pcrit(c(200,150,50), pmax = .2, pdesired = .05, slices = 1000, tails = 2)
pcrit()

ianhussey/ethicalpeeking documentation built on May 18, 2019, 1:28 a.m.