[R] comparing attitudes of 2 groups / likert scales?

[David Winsemius]

On Apr 19, 2010, at 10:08 AM, Tal Galili wrote:

> Good luck in your work,
>
> The simple solution would be to run many non-paired wilcox on all  
> the 20
> questions (the way Dieter suggested).
> In which case, make sure to adjust for multiple comparisons.  Read  
> about it,
> and see:
> ?p.adjust
> If you have some questions you can merge (by a simple mean of them),  
> it will
> probably do you good (using PCA might be an option, but it could  
> also be an
> over kill for you).
>
>
> You might also be interested in plotting your data, here is a nice  
> simple
> hack on how to display the Correlation scatter-plot matrix for your  
> data:
> http://www.r-statistics.com/2010/04/correlation-scatter-plot-matrix-for-ordered-categorical-data/
>
>
> And Dieter, thanks for a great quote: "Assess independence,  
> equalvariance
> and normality -in that order" (van Bell, Statistical rules of thumb)."

If you are thinking of using that quote, you might want to check the  
spelling of his name. My memory is van Belle.

-- 
David.

>
>
> Tal
>
>
> ----------------Contact
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> ----------------------------------------------------------------------------------------------
>
>
>
>
> On Mon, Apr 19, 2010 at 2:07 PM, Mona_m  
> <purplemind at blueyonder.co.uk> wrote:
>
>>
>> Hi,
>>
>> I have just found this forum, and it looks like a great place to  
>> get some
>> help (I hope)
>> For my dissertation, which is due way too soon, I am doing a survey,
>> comparing attitudes of 2 independent groups, with 5 scale likert  
>> questions.
>> Basically I want to show if they have similar or different  
>> attitudes. I am
>> testing 4 hypotheses, and have in total about 20 questions.
>>
>> I have to say my statistic skills are very basic and very rusty, we  
>> had
>> some
>> lectures two years ago, where we were introduced to R. I looked  
>> through my
>> notes, and back then we did a one sample t-test to analyse likert  
>> type
>> questions. I believe I would need to do a 2 sample unpaired t- 
>> test.  It
>> would be great if someone could give me some feedback if this test  
>> is the
>> most suitable one for my purpose, and maybe could explain to me  
>> what’s the
>> easiest way to do this in R?
>>
>> You would help me loads!!
>> Many thanks in advance
>> Mona
>>
>> --
>> View this message in context:
>> http://n4.nabble.com/comparing-attitudes-of-2-groups-likert-scales-tp2015738p2015738.html
>> Sent from the R help mailing list archive at Nabble.com.
>>
>> ______________________________________________
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>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
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>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
West Hartford, CT