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Compares and combines Pearson or partial correlations in original and follow-up studies

Source: R/meta_rep.R
replicate.cor.Rd

This function can be used to compare and combine Pearson or partial correlations from an original study and a follow-up study. The confidence level for the difference is 1 – 2*alpha, which is recommended for equivalence testing.

For more details, see Chapter 4 of Bonett (2021, Volume 5).

Usage

replicate.cor(alpha, cor1, n1, cor2, n2, s)

Arguments

alpha

alpha level for 1-alpha confidence

cor1

estimated correlation in original study

n1

sample size in original study

cor2

estimated correlation in follow-up study

n2

sample size in follow-up study

s

number of control variables in each study (0 for Pearson)

Value

A 4-row matrix. The rows are:

  • Row 1 summarizes the original study

  • Row 2 summarizes the follow-up study

  • Row 3 estimates the difference in correlations

  • Row 4 estimates the average correlation

The columns are:

  • Estimate -correlation estimate (single study, difference, average)

  • SE - standard error

  • z - t-value for rows 1 and 2; z-value for rows 3 and 4

  • p - p-value

  • LL - lower limit of the confidence interval

  • UL - upper limit of the confidence interval

References

Bonett DG (2021). “Design and analysis of replication studies.” Organizational Research Methods, 24(3), 513–529. ISSN 1094-4281, doi:10.1177/1094428120911088 .

Bonett DG (2021). Statistical Methods for Psychologists, Vol 1-5, https://dgbonett.sites.ucsc.edu/.

Examples

replicate.cor(.05, .598, 80, .324, 200, 0)
#>                       Estimate      SE     z     p     LL     UL
#> Original:                0.598 0.07321 6.589 0.000 0.4355 0.7228
#> Follow-up:               0.324 0.06377 4.819 0.000 0.1940 0.4428
#> Original - Follow-up:    0.274 0.09709 2.633 0.008 0.1065 0.4265
#> Average:                 0.461 0.04854 7.635 0.000 0.3725 0.5412

# Should return:
#                       Estimate      SE     z     p     LL     UL
# Original:                0.598 0.07321 6.589 0.000 0.4355 0.7228
# Follow-up:               0.324 0.06377 4.819 0.000 0.1940 0.4428
# Original - Follow-up:    0.274 0.09709 2.633 0.008 0.1065 0.4265
# Average:                 0.461 0.04854 7.635 0.000 0.3725 0.5412