Simple Main Effects in JASP - R code?

chris383

Hi,

I was wondering if anyone knew what R package or code JASP uses for running Simple Main Effects. I know RM anova is through aov_car, but looking through that package, it doesn't seem to have a method for that. Does JASP just filter (via dplyr) for the simple effect factor and run another ANOVA? Does it use the tidyverse and nest/unnest factors and just run a regular aov? I used to try and look through the R code I could find on Github from JASP, but it's become a lot harder to do that, so I apologize if this is an obvious question.

Thanks!

MSB

In R, all the follow up analyses are done with the {emmeans} package.

• Contrasts with emmeans::contrasts
• Simple effects with emmeans::joint_tests
• Etc...

EJ

I'll ask, but the help file does mention the emmeans package, so that would support the conjecture from MSB.

E.J.

JohnnyB

Hi Chris,

All JASP modules are now in separate github modules - you can see the ANOVA repository here.

The R code for the simple main effects is on line 1573. The computation is a combination of emmeans and some manual computations for correcting the sums of squares and degrees of freedom.

Kind regards

Johnny