[R] Error() model is singular - what does that mean

[Jessica Streicher]

Just looking at it i would try renaming Task-Kind, Data-Kind an Time-Taken
Those are ambiguous in the Formula.

"Task-Kind" vs "Task" - "Kind"

Though that might not be the error at hand :)


On 02.07.2012, at 14:15, zetwal wrote:

> Hello
> 
> I have some test data that looks like that from a within subject experiment.
> Subject   Task-Kind    Data-Kind   Time-Taken   Correct
> 1    A      Data1     5   1
> 1    A      Data1     3   0
> 1    A      Data1     1   1
> 1    A      Data2     8   1
> 1    A      Data2     7   0
> 1    A      Data2     5   0
> 1    A      Data3     2   1
> 1    A      Data3     7   0
> 1    A      Data3    5    0
> 1    A      Data3    6    0
> 1    B      Data1     3   1
> 1    B      Data1     1   1
> 1    B      Data1     3   0
> 1    B      Data2     9   0
> 1    B      Data2     8   1
> 1    B      Data2     5  0
> 1    B      Data3     2   1
> 1    B      Data3     7   2
> 1    B      Data3    5    3
> 1    B      Data3    6    0
> 1    C      Data1     3   1
> 1    C      Data1     1   1
> 1    C      Data1     3   0
> 1    C      Data2     9   0
> 1    C      Data2     8   1
> 1    C      Data2     5  0
> 1    C      Data3     2   1
> 1    C      Data3     7   2
> 1    C      Data3    5    3
> 1    C      Data3    6    0
> 2    A      Data1     5   1
> 2    A      Data1     3   0
> 2    A      Data1     1   1
> 2    A      Data2     8   1
> 2    A      Data2     7   0
> 2    A      Data2     5   0
> 2    A      Data3     2   1
> 2    A      Data3     7   0
> 2    A      Data3    5    0
> 2    A      Data3    6    0
> 2    B      Data1     3   1
> 2    B      Data1     1   1
> 2    B      Data1     3   0
> 2    B      Data2     9   0
> 2    B      Data2     8   1
> 2   B      Data2     5  0
> 2    B      Data3     2   1
> 2    B      Data3     7   2
> 2    B      Data3    5    3
> 2    B      Data3    6    0
> 2    C      Data1     3   1
> 2    C      Data1     1   1
> 2    C      Data1     3   0
> 2    C      Data2     9   0
> 2    C      Data2     8   1
> 2    C      Data2     5  0
> 2    C      Data3     2   1
> 2    C      Data3     7   2
> 2    C      Data3    5    3
> 2    C      Data3    6    0
> .
> .
> .
> 
> some notes:
> there are 20 subjects
> there are 5 different kinds of tasks
> There are 5 different kinds of data
> and there are several different variations for a certain kind of task and
> kind of data which is why for Subject = 1   Task-Kind=A  and Data-Kind=Data1 
> we have 3 different results.
> 
> The measured parameters are time to complete the task and whether it was
> correct or not (0 implies correct and 1 implies not correct)
> 
> I am computing the anova as follows:
> aov.ex =
> aov(Correct~Task-Kind*Data-Kind+Error(Subject/(Task-Kind*Data-Kind)),data=allDataRaw.xp)
> 
> since I want to see how the result is affected by the different kinds of
> data as well as the the kind of task and I get a warning message saying:
> Error() model is singular
> 
> I would be very grateful if someone could please tell me what does this
> mean.
> Thanks
> Pascal
> 
> --
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