[R-sig-ME] I would need some advice about repeated anova 2 ways and how to code it within lmer function

[Jeff Newmiller]

I am barely functional with mixed models, but your email is barely legible (you sent HTML formatted email but we received only plain text per the Posting Guide mentioned at the bottom of every message on this list) so I thought you should at least know we don't see whatever you saw when you sent it.

From what I can gather, you claim to be more interested in time effect but you only have three points in time but five in frequency. I think you are going to have a very difficult time extracting statistically meaningful model characterization with respect to time from this data set.

Mixed models generally require significantly more data to draw conclusions than lm/glm models... but they also try to extract more information from the data set. Are you sure an lm or glm model isn't better suited for this?

On October 10, 2022 11:27:29 PM PDT, claire.dv04 using gmail.com wrote:
>Dear all
>
>I would appreciate some advice about how to analyze my data.
>
>These data come from an experiment during which the hearing of 18 ears was
>measured over time and according to different frequencies.
>
>Each ear was measured at T1, T21, and T 28, and at each of its times, each
>ear was measured at frequencies 4000Hz, 8000Hz, 16000Hz, 25000Hz, and
>32000Hz.
>
>I especially want to know if there is a time effect. The frequency effect
>does not particularly interest me.
>
>I was thinking of using a 2-factor anova for repeated data (with 2 factors
>within: time (=Point)  and frequency), but I$B!G(Bm note sure.
>
>I work with R and I thought to use the lmer function with this code:
>
>mod.lmer $B"+(B lmer(hearing ~ Point * Hz Frequency +(1|id/Point) +(1|id/Hz
>Frequency),
>contrasts=list(Point=contr.sum, Frequency Hz=contr.sum),
>data=mydata)
>
>id is the ear identification factor
>
>I$B!G(Bm not sure about the coding of random effects (1|id/Point)
>+(1|id/Frequency Hz), but they give me the same results as the aov.ez
>function of the afex package :
>
>mod.ez $B"+(B aov_ez(id=$B!H(Bid$B!I(B,
>dv=$B!H(BThreshold dB$B!I(B,
>data=mydata,
>within = c($B!H(BPoint$B!I(B, $B!H(BFrequency Hz$B!I(B))
>
>What do you think ?
>
>Does this analysis seem correct to you? If not, what can you suggest me?
>
>Thanks in advance for any help you can give me.
>
>All the best
>
>Claire Della Vedova
>
> 
>
>
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>
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-- 
Sent from my phone. Please excuse my brevity.