[R-sig-ME] longitudinal analysis when one group switched from control to treatment

[Simon Harmel]

Dear Thierry,

By "Have a look at the residuals" you mean something like the following
(below)? So no other adjustment is required for the switching that occurred?

plot(m1, type = c("p","smooth"), col.line = 2)

plot(m1, sqrt(abs(resid(.)))~fitted(.), type = c("p","smooth"), col.line =
2)

On Mon, May 18, 2020 at 2:01 AM Thierry Onkelinx <thierry.onkelinx using inbo.be>
wrote:

> Dear Simon,
>
> The question is rather if the model is able to capture this change. Have a
> look at the residuals. If they look OK, then the model handles the change
> in treatment.
>
> Best regards,
>
> ir. Thierry Onkelinx
> Statisticus / Statistician
>
> Vlaamse Overheid / Government of Flanders
> INSTITUUT VOOR NATUUR- EN BOSONDERZOEK / RESEARCH INSTITUTE FOR NATURE AND
> FOREST
> Team Biometrie & Kwaliteitszorg / Team Biometrics & Quality Assurance
> thierry.onkelinx using inbo.be
> Havenlaan 88 bus 73, 1000 Brussel
> www.inbo.be
>
>
> ///////////////////////////////////////////////////////////////////////////////////////////
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> than asking him to perform a post-mortem examination: he may be able to say
> what the experiment died of. ~ Sir Ronald Aylmer Fisher
> The plural of anecdote is not data. ~ Roger Brinner
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> ensure that a reasonable answer can be extracted from a given body of data.
> ~ John Tukey
>
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>
> <https://www.inbo.be>
>
>
> Op zo 17 mei 2020 om 01:09 schreef Simon Harmel <sim.harmel using gmail.com>:
>
>> Hello All,
>>
>> I have a 3-year longitudinal dataset (*see link below the table*). Up to
>> year 2 (coded "1"), 8 schools (4 in Treatment, 4 in Control) cooperated
>> with the study. But in year 3 (coded "2"), one of the Treatment schools
>> (named "good") dropped out.
>>
>> Also in year 3 (coded "2"), we were made to move one of the *Control
>> *schools
>> (named "*orange*") to the *Treatment *group. The full design of the study
>> is shown in the Table below.
>>
>> I want to regress "year" and "group" on "y" (a continuous response) in
>> lme4
>> package in R. But is there a way to capture the switch of one of the
>> control schools to the treatment group?
>>
>> Thank you very much, Simon
>>
>> ·       *Switched from control to treatment*
>>
>> ·       *Out as of year coded 2*
>>
>> *SCHOOL NAMES*
>>
>> *Year*
>>
>> *Codes*
>>
>> *Control*
>>
>> *Treatment*
>>
>> 0
>>
>> har
>>
>> john
>>
>> bus
>>
>> orange
>>
>> caro
>>
>> good
>>
>> bla
>>
>> carm
>>
>> 1
>>
>> har
>>
>> john
>>
>> bus
>>
>> *orange*
>>
>> caro
>>
>> good
>>
>> bla
>>
>> carm
>>
>> 2
>>
>> har
>>
>> john
>>
>> bus
>>
>> X
>>
>> caro
>>
>> *orange*
>>
>> bla
>>
>> carm
>>
>> *library(lme4)*
>> *dat <- read.csv('https://raw.githubusercontent.com/hkil/m/master/z.csv
>> <https://raw.githubusercontent.com/hkil/m/master/z.csv>')*
>>
>> *m1 <- lmer(y~ year*group + (1|stid), data = dat)      #### 'stid' =
>> student id                m2 <- lmer(y~ year*group + (1|scid/stid), data =
>> dat) #### 'scid' = school id*
>>
>>         [[alternative HTML version deleted]]
>>
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>> https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models
>>
>

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