Setting Contrasts for ANOVA in R

Question

I've been attempting to perform an ANOVA in R recently on the attached data frame.

My question revolves around the setting of contrasts.

My design is a 3x5 within-subjects design.

There are 3 visual conditions under 'Circle1' and 5 audio under 'Beep1'.

Does anyone have any idea how I should set the contrasts? This is something I'm unfamiliar with as I'm making the transition from point and click stats in SPSS to coded in R.

Thanks for your time

Data file:

Answer 1

Reiterating my answer from another stackoverflow question that was flagged as similar, since you didn't provide any code, you might start by having a look at the contrast package in R. As they note in the document:

"The purpose of the contrast package is to provide a standardized interface for testing linear combinations of parameters from common regression models. The syntax mimics the contrast. Design function from the Design library. The contrast class has been extended in this package to linear models produced using the functions lm, glm, gls, lme and geese."

There is also a nice little tutorial here by Dr. William King who talks about factorial between subjects ANOVA and also includes an abundance of R code. This is wider scoped than you question but would be a great place to start (just to get context).

Finally, here is another resource that you can refer to which talks about setting up orthogonal contrasts in R.