Re: [AUDITORY] stats use in psychology and hearing science

[Daniel Oberfeld <oberfeld@xxxxxxxxxxxx>]

Dear list,

important topic! A related while probably less general problem is that 
data from repeated-measures / within-subjects designs (that is, when a 
subject is tested in more than one experimental condition) are sometimes 
not analyzed properly. I've seen quite a few papers in hearing science 
where the authors used an ANOVA for completely randomized / 
between-subjects design for repeated-measures data (you can spot this 
problem by examining the degrees-of freedom for the F-tests), or fail to 
use the appropriate repeated-measures ANOVA approach (e.g., apply no 
correction for the degrees-of-freedom when using a univariate approach).

Another point that should be considered is that while for 
between-subjects designs the general linear model is very robust against 
non-normality, this is unfortunately *not* the case for 
repeated-measures designs. Therefore, when analyzing non-normal data 
like error rates, percent correct or response times from a 
within-subjects design, the p-values you get from the rmANOVA could be 
either on the conservative or on the liberal side.

You can find an in-depth discussion of these issues in a recent paper 
from my lab (http://link.springer.com/article/10.3758%2Fs13428-012-0281-2).

Best

Daniel

--
PD Dr. Daniel Oberfeld-Twistel
Johannes Gutenberg - Universitaet Mainz
Department of Psychology
Experimental Psychology
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