[R] repeated measures ANOVA - among group differences

Wed Apr 1 14:10:01 CEST 2009

Hm, it seems I possibly used the technical term "nested"
inappropriately in my response. I meant:

"If Month is a repeated measure within each Quadrat..."
and
"If Treatment is also a repeated measure within each Quadrat..."

On Wed, Apr 1, 2009 at 8:21 AM, Mike Lawrence <Mike.Lawrence at dal.ca> wrote:
> If Month is nested within Quadrat I think you want:
> aov(ProportioninTreatment ~ Treatment*Month +Error(Quadrat/Month), RM)
>
> If Treatment is also nested within Quadrat, you want:
> aov(ProportioninTreatment ~ Treatment*Month
> +Error(Quadrat/(Treatment*Month)), RM)
>
>
> On Wed, Apr 1, 2009 at 12:42 AM, Jessica L Hite/hitejl/O/VCU
> <hitejl at vcu.edu> wrote:
>>
>>
>> I have data on the proportion of clutches experiencing different fates
>> (e.g., 4 different sources of mortality) for 5 months . I need to test 1)
>> if the overall proportion of these different fates is different over the
>> entire study and 2) to see if there are monthly differences within (and
>> among) fate types. Thus, I am pretty sure this is an RM analysis -( I
>> measure the same quadrats each month).
>>
>> I am fine running the analysis in R - with the code below, however, there
>> is no output for the among group variation...this is an important component
>> - any ideas on how to solve this problem?
>>
>> I have included code and sample data below.
>>
>> Many thanks in advance for help and suggestions.
>>
>> J
>>
>>  both.aov <- aov(ProportioninTreatment ~ factor(Treatment)*factor(Month) +
>> Error(factor(Quadrat)), RM)
>>
>> Error: factor(id)
>>          Df  Sum Sq Mean Sq F value Pr(>F)
>> Residuals  3 0.51619 0.17206               #####why only partial output
>> here? #######
>>
>> Error: Within
>>                   Df Sum Sq Mean Sq F value   Pr(>F)
>> factor(Fate1)       3 1.2453  0.4151  3.5899 0.017907 *
>> time                1 0.9324  0.9324  8.0637 0.005929 **
>> factor(Fate1):time  3 0.9978  0.3326  2.8763 0.042272 *
>> Residuals          69 7.9783  0.1156
>>
>>
>>
>>
>> Fate1 Proportion in Fate      ASIN  Month Quadrat
>> 1     0.117647059 0.350105778 1     1
>> 1     0     0     2     1
>> 1     0.111111111 0.339836909 3     1
>> 1     0     0     4     1
>> 1     0     0     5     1
>> 1     0     0     1     2
>> 1     0     0     2     2
>> 1     0.2   0.463647609 3     2
>> 1     0.25  0.523598776 4     2
>> 1     0.111111111 0.339836909 5     2
>> 1     0     0     1     3
>> 1     0     0     2     3
>> 1     0     0     3     3
>> 1     0.384615385 0.668964075 4     3
>> 1     0     0     5     3
>> 1     0     0     1     4
>> 1     0     0     2     4
>> 1     0     0     3     4
>> 1     0.166666667 0.420534336 4     4
>> 1     0     0     5     4
>> 2     0.352941176 0.636132062 1     1
>> 2     0.2   0.463647609 2     1
>> 2     0.333333333 0.615479708 3     1
>> 2     1     1.570796327 4     1
>> 2     0     0     5     1
>> 2     0.5   0.785398163 1     2
>> 2     0     0     2     2
>> 2     0.6   0.886077124 3     2
>> 2     0.416666667 0.701674124 4     2
>> 2     0.222222222 0.490882678 5     2
>> 2     0     0     1     3
>> 2     0.2   0.463647609 2     3
>> 2     0     0     3     3
>> 2     0.461538462 0.746898594 4     3
>> 2     0     0     5     3
>> 2     0     0     1     4
>> 2     0     0     2     4
>> 2     0.307692308 0.588002604 3     4
>> 2     0.666666667 0.955316618 4     4
>> 2     0     0     5     4
>> 3     0     0     1     1
>> 3     0     0     2     1
>> 3     0.444444444 0.729727656 3     1
>> 3     0     0     4     1
>> 3     1     1.570796327 5     1
>> 3     0.5   0.785398163 1     2
>> 3     0     0     2     2
>> 3     0     0     3     2
>> 3     0.25  0.523598776 4     2
>> 3     0.555555556 0.841068671 5     2
>> 3     0     0     1     3
>> 3     0     0     2     3
>> 3     0     0     3     3
>> 3     0.153846154 0.403057075 4     3
>> 3     0.666666667 0.955316618 5     3
>> 3     0     0     1     4
>> 3     0     0     2     4
>> 3     0     0     3     4
>> 3     0     0     4     4
>> 3     0.875 1.209429203 5     4
>> 4     0.294117647 0.573203309 1     1
>> 4     0.2   0.463647609 2     1
>> 4     0     0     3     1
>> 4     0     0     4     1
>> 4     0     0     5     1
>> 4     0     0     1     2
>> 4     0     0     2     2
>> 4     0     0     3     2
>> 4     0.083333333 0.292842771 4     2
>> 4     0.111111111 0.339836909 5     2
>> 4     0     0     1     3
>> 4     0     0     2     3
>> 4     0     0     3     3
>> 4     0     0     4     3
>> 4     0.166666667 0.420534336 5     3
>> 4     0     0     1     4
>> 4     0     0     2     4
>> 4     0.461538462 0.746898594 3     4
>> 4     0     0     4     4
>> 4     0.125 0.361367124 5     4
>>        [[alternative HTML version deleted]]
>>
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>>
>
>
>
> --
> Mike Lawrence
> Graduate Student
> Department of Psychology
> Dalhousie University
>
> Looking to arrange a meeting? Check my public calendar:
> http://tinyurl.com/mikes-public-calendar
>
> ~ Certainty is folly... I think. ~
>

-- 
Mike Lawrence
Graduate Student
Department of Psychology
Dalhousie University

Looking to arrange a meeting? Check my public calendar:
http://tinyurl.com/mikes-public-calendar

~ Certainty is folly... I think. ~