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Compares and combines Spearman correlations in original and follow-up studies

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

This function can be used to compare and combine Spearman 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.spear(alpha, cor1, n1, cor2, n2)

Arguments

alpha

alpha level for 1-alpha confidence

cor1

estimated Spearman correlation in original study

n1

sample size in original study

cor2

estimated Spearman correlation in follow-up study

n2

sample size in follow-up study

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 - Spearman correlation estimate (single study, difference, average)

  • SE - standard error

  • z - z-value

  • 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.spear(.05, .598, 80, .324, 200)
#>                       Estimate      SE     z     p     LL     UL
#> Original:                0.598 0.07948 5.315 0.000 0.4199 0.7318
#> Follow-up:               0.324 0.06542 4.571 0.000 0.1905 0.4457
#> Original - Follow-up:    0.274 0.10294 3.438 0.001 0.0948 0.4342
#> Average:                 0.461 0.05147 9.968 0.000 0.3670 0.5457

# Should return:
#                       Estimate      SE     z     p     LL     UL
# Original:                0.598 0.07948 5.315 0.000 0.4199 0.7318
# Follow-up:               0.324 0.06542 4.571 0.000 0.1905 0.4457
# Original - Follow-up:    0.274 0.10294 3.438 0.001 0.0948 0.4342
# Average:                 0.461 0.05147 9.968 0.000 0.3670 0.5457