Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: RE: Mean test in a Likert Scale
From
"David Radwin" <[email protected]>
To
<[email protected]>
Subject
st: RE: Mean test in a Likert Scale
Date
Thu, 30 Aug 2012 16:13:22 -0700 (PDT)
Leonor,
No, you can't correctly calculate the mean of an ordinal-level measure
like the Likert scale you describe, although plenty of people do it
anyway.
But you can use -ttest- with these data if you first collapse each
variable to a dichotomous (dummy) variable, because the mean of a
dichotomous variable is identical to the proportion where the value is 1.
As a guess, you might set the highest two values to 1, the lowest two
values to 0, and the middle value to missing to calculate the proportion
agreeing or somewhat agreeing.
David
--
David Radwin
Senior Research Associate
MPR Associates, Inc.
2150 Shattuck Ave., Suite 800
Berkeley, CA 94704
Phone: 510-849-4942
Fax: 510-849-0794
www.mprinc.com
> -----Original Message-----
> From: [email protected] [mailto:owner-
> [email protected]] On Behalf Of Leonor Saravia
> Sent: Thursday, August 30, 2012 3:23 PM
> To: [email protected]
> Subject: st: Mean test in a Likert Scale
>
> Hello,
>
> I'm working with a survey that presents 26 questions and each of them
> has as possible answer a 5 point Likert scale from Desagree (1) to
> Agree (5). This survey was applyed for a treatment and a control
> group.
>
> As far as I know, it is possible to analyze the information given only
> by the proportions of each answer; for instance, 25% agrees, 50%
> desagree, or so.
>
> I have two questions that maybe one of you have had before:
>
> a) Is it possible to calculate the mean score of a sample (treatment
> or control group) - adding the individual answers - when one is
> working with a Likert scale?
>
> b) If it is possible to calculate a mean score of a sample when using
> a Likert scale, to compare the answers of the treatment versus the
> control group, is it well done if I use the 'ttest' command?
>
>
> Thank you in advance.
>
> Best regards,
>
> Leonor
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/