Hi According to some sources, yours would be a medium size effect.
“Further confusion surrounds the benchmarks suggested by Cohen (1969, pp. 278–280)<http://www.sciencedirect.com/science/article/pii/S1747938X11000029#bib0050> to define small, medium, and large effects. As was explained earlier, these were based upon values of f that correspond to values of partial η2 of .0099, .0588, and .1379, respectively.” One complication in interpreting partial eta2 is its dependence on the denominator, which will vary depending on how much variability the other effects account for. In your case, .061 = 11.593 / (11.593 + 179.626) But SS Error = 179.626 < SS Total = 1302 because other effects account for much of the 1302 units of variability. Without those other effects, partial eta2 would be smaller and with additional other effects partial eta2 would be larger. Given the complexities, Michael’s advice would be a sensible way to go if you can find relevant prior literature using partial eta2. Take care Jim Jim Clark Professor of Psychology University of Winnipeg 204-786-9757 Room 4C78A (4th Floor Centennial) www.uwinnipeg.ca/~clark<http://www.uwinnipeg.ca/~clark> From: Michael Scoles [mailto:micha...@uca.edu] Sent: Friday, December 08, 2017 2:23 PM To: Teaching in the Psychological Sciences (TIPS) Subject: Re: [tips] interpretations of partial eta squared Despite the "rules of thumb" for various measures of effect size, what is common in the literature for a particular area is a better guide. On Fri, Dec 8, 2017 at 1:46 PM, Annette Taylor <tay...@sandiego.edu<mailto:tay...@sandiego.edu>> wrote: I am a stats moron by self-description. Although I "aced" stats in graduate school in the 1970's/1980's I am woefully behind in anything new since then. So I would appreciate if someone can give me at least a quick and dirty heuristic for interpreting the size of partial eta squared in SPSS. I did google it but got little helpful guidance. Here is the situation: I have a 2 x 2 x 2 anova with a main effect on one of the variables. Here is the output line: Source Type III Sum of Squares df Mean Square F Sig. Partial Eta Squared Refute2 11.593 1 11.593 10.004 .002 .061 Error 179.626 155 1.159 Total 1302.000 163 I am concerned that even though the p value is quite nice, the partial eta squared at .061 is hard to make sense of. Is this a good effect size or is this a tiny effect size? Thanks to you stats mavens! Reading about eta squared versus partial eta squared just didn't answer my questions. Annette Annette Kujawski Taylor, Ph.D. Professor, Psychological Sciences University of San Diego 5998 Alcala Park<https://maps.google.com/?q=5998+Alcala+ParkSan+Diego,+CA&entry=gmail&source=g> San Diego, CA<https://maps.google.com/?q=5998+Alcala+ParkSan+Diego,+CA&entry=gmail&source=g> 921210 tay...@sandiego.edu<mailto:tay...@sandiego.edu> --- You are currently subscribed to tips as: micha...@uca.edu<mailto:micha...@uca.edu>. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=357701.a768e95c4963686e69b47febf8aa657a&n=T&l=tips&o=51859 (It may be necessary to cut and paste the above URL if the line is broken) or send a blank email to leave-51859-357701.a768e95c4963686e69b47febf8aa6...@fsulist.frostburg.edu<mailto:leave-51859-357701.a768e95c4963686e69b47febf8aa6...@fsulist.frostburg.edu> -- Michael T. Scoles, Ph.D. Associate Professor of Psychology & Counseling University of Central Arkansas Conway, AR 72035 501-450-5418 --- You are currently subscribed to tips as: j.cl...@uwinnipeg.ca<mailto:j.cl...@uwinnipeg.ca>. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=3229968.90f21a83d5f62f052ba84a49e2f91291&n=T&l=tips&o=51860 (It may be necessary to cut and paste the above URL if the line is broken) or send a blank email to leave-51860-3229968.90f21a83d5f62f052ba84a49e2f91...@fsulist.frostburg.edu<mailto:leave-51860-3229968.90f21a83d5f62f052ba84a49e2f91...@fsulist.frostburg.edu> --- You are currently subscribed to tips as: arch...@mail-archive.com. To unsubscribe click here: http://fsulist.frostburg.edu/u?id=13090.68da6e6e5325aa33287ff385b70df5d5&n=T&l=tips&o=51861 or send a blank email to leave-51861-13090.68da6e6e5325aa33287ff385b70df...@fsulist.frostburg.edu
