0todd0000
commented
3 years ago Hi Paolo,
For deciding between the ANOVA designs you just need to know the conditions in which each subject performed. If a given subject performed in all conditions, then the appropriate design is anova2rm. If a given subject performed in multiple but not all conditions the design is likely anova2onerm. (There shouldn't be an anova2tworm design; there is only an anova3tworm for a three-way ANOVA with two RM factors.)
In this case it sounds like anova2rm is appropriate. An example of a case where anova2onerm would be appropriate is two populations (e.g. patients and controls) and two conditions (e.g. shod and barefoot); in this case a specific individual can't both be a patient and a control.
How the variables should be organized? ( I am using matlab)
You need:
y= data; a (J, Q) array where J is the number of observations and Q is the number of time nodesA= Factor A levels (e.g. barefoot=1, orthosis=2); a (J,1) arrayB= Factor B levels (e.g. M1=1, M2=2, M3=3); a (J,1) arrayS= Subject integer labels; a (J,1) array
The example script: ./spm1dmatlab/examples/stats1d/ex1d_anova2rm.m shows a few examples of how the data should be set up.
Todd
PaoloBrasi
Hello Todd, I have a question regarding which is the most appropriate test between anva2rm, anova2onerm and anova2tworm. I'll explain the experimental set up. I have 14 subjects which underwnt instrumented (stereophotogrammetry) gait analysis in two conditions: walking barefoot (C1) and walking while wearing an orthosis (C2). Kinematics was estimated using 3 different 3D models to reconstruct body segemnts (M1, M2 and M3). I am using the most representiative trial for each subject, so I have the same number of trials for each condition and model. I am interested in verifying if there are differences between the three models in each condition and i would like to understand how much these differences may be affected by the conditions. I have to main questions: Which is the most appropriate test to be used in this case? How the variables should be organized? ( I am using matlab)
Thank you in advance and kind regards,
Paolo.