Hi R people,

I have a very basic question to ask - I'm sorry if it's been asked before, but 
I searched the archives and could not find an answer.  All the examples I found 
were much more complicated/nuanced versions of the problem - my question is 
much more simple.

I have data with multiple, nested fixed effects (as I understand it, fixed 
effects are specified by the experimental design while random effects are 
measured) and one continuous response variable.  All the fixed effects are 
catagorical.  

e.g.
fix1    fix2    fix3    response
0    0    0    16.260
0    0    0    16.128
0    0    1    22.969
0    0    1    23.245
0    1    0    14.687
0    1    0    14.635
0    1    1    22.954
0    1    1    23.345
1    0    0    19.866
1    0    0    19.589
1    0    1    22.748
1    0    1    22.817
1    1    0    17.861
1    1    0    17.872
1    1    1    22.925
1    1    1    23.138

I was thinking I could use a linear model to determine whether any of the 
nested fixed effects or their interactions effect the response, but I could not 
determine how to specify whether effects were fixed or random, and how to 
specify nesting.  

For example:
lm(response~ fix1+fix2+fix3)

The above, as I understand it, simply asks whether the effects fix1 through 
fix4 have an effect on the response.  However, in reality my experimental 
design has multiple levels of nesting:

fix1(fix2(fix3(fix4)))

So, how do I do this?  To specify nesting, do I need to use another type of 
model such as lmer or glm? 

I also don't know whether the above example is specifying whether the effects 
are fixed or random - how do I do this?

Thanks very much,
Jojo



      
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