- Understanding "Power" - Type I and Type II Errors
- Learning how to compute power, sample size and effect sizes
- PPT SLIDES - click to download
-
G*Power (FREE)
- https://www.psychologie.hhu.de/arbeitsgruppen/allgemeine-psychologie-und-arbeitspsychologie/gpower
- register, then scroll down to download software
- more help at UCLA - Advanced Research Computing: Statistical Methods and Data Analytics, https://stats.oarc.ucla.edu/other/gpower/
-
NCSS/PASS
- This software does cost money, but the documentation is FREE to access and read.
- Go to FREE Documentation at https://www.ncss.com/software/pass/pass-documentation/
- Go to Introduction and Read "Intro to Power Analysis" at https://www.ncss.com/wp-content/themes/ncss/pdf/Procedures/PASS/Introduction_to_Power_Analysis.pdf
A really helpful website:
- https://www.psychometrica.de/effect_size.html - go to item 14 to convert between different effect sizes
- https://www.psychometrica.de/effect_size.html - also see item 16 for "Table of interpretation for different effect sizes""
- "Post hoc power analysis: an idea whose time has passed?" by M. Levine, M. H. Ensom https://pubmed-ncbi-nlm-nih-gov.proxy.library.emory.edu/11310512/
- "The Abuse of Power: The Pervasive Fallacy of Power Calculations for Data Analysis" John M. HOENIG and Dennis M. HEISEY https://www.vims.edu/people/hoenig_jm/pubs/hoenig2.pdf