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Power analysis for longitudinal multilevel models: powerlmm 0.3.0 is now out on CRAN

Posted by Kristoffer Magnusson on 2018-04-17 22:38:00+02:00 in R

Tagged as power powerlmm statistics longitudinal multilevel linear mixed-effects models lme4

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My R package powerlmm 0.3.0 is now out on CRAN. It can be installed from CRAN https://cran.r-project.org/package=powerlmm or GitHub https://github.com/rpsychologist/powerlmm.

New features

This version adds support for raw effect sizes, and new standardized effect sizes using the function cohend(...). Here's an example that use the different types.

p <- study_parameters(n1 = 11,
                      n2 = 25,
                      icc_pre_subject = 0.5,
                      var_ratio = 0.03,
                      effect_size = c(10, # raw
                                     cohend(0.5, standardizer = "pretest_SD"),
                                     cohend(0.5, standardizer = "posttest_SD"),
                                     cohend(0.5, standardizer = "slope_SD"))
                       )

Other changes

  • Support for lmerTest 3.0.
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