st: Mean test in a Likert Scale

[Leonor Saravia <lmisaravia@gmail.com>]

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
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