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Transforms a t-statistic into Jeffreys' approximate Bayes factor

Source: R/JABt.R
JABt.Rd

Converts a t-statistic (or z-statistic) into Jeffreys' approximate Bayes factor, given the sample size. Vectorized over n and t.

Usage

JABt(n, t, method = "JAB", upper = 1)

Arguments

n

Sample size. A positive numeric vector.

t

The t-statistic.

method

Used for the choice of 'b'. Currently one of:

  • "JAB": this choice of b produces Jeffreys' approximate BF (Wagenmakers, 2022)

  • "min": uses the minimal training sample for the prior (Gu et al., 2018)

  • "robust": a robust version of "min" that prevents too small b (O'Hagan, 1995)

  • "balanced": this choice of b balances the type I and type II errors (Gu et al., 2016)

upper

The upper limit for the range of realistic effect sizes. Only relevant when method="balanced". Defaults to 1 such that the range of realistic effect sizes is uniformly distributed between 0 and 1, U(0,1).

Value

A numeric value for the BF in favour of H1.

Examples

# Transform a t-statistic of 2.695 computed based on a sample size of 200 into JAB
JABt(200, 2.695)
#> [1] 2.670735