Re: A 4 point Likert scale

Posted by Mohamed on Oct 18, 2011; 9:44pm
URL: http://spssx-discussion.165.s1.nabble.com/A-4-point-Likert-scale-tp4910676p4915948.html

Hello

Thank you for your help. I appreciate it.

First of all I am novice in that and I wanted to avoid making fatal mistakes !

The reason I asked this is that I saw on the internet someone's power point slides wheres/he warned against using 4 point and some tests. 

So for me it was the 4 point rather than Likert itself ! As I am interested in ruling out the so called 'fence-sitters' I wanted to use 4 points. However, to have a better covariance, I was advised to use 6 points !

In a day and night the whole issue got another radical dimension.

Is it ordinal or interval? parametric or non-parametric.' Hamlet's  unasked questions !

As you guessed I have already got the answers and as you know, beforehand, giving mixed messages.

This was good opportunity to learn about that for a novice, though confusing.

However, Now I know it is not my own problem. It is a 'global' issue !!

Thank you very much

Mohamed

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From: Rich Ulrich <[hidden email]>
To: [hidden email]; SPSS list <[hidden email]>
Sent: Tuesday, October 18, 2011 3:37 AM
Subject: RE: A 4 point Likert scale

I've seen a number of messages about why 4-points is
not as good as 5 or 6, for reasons of precision and bias.

However, none of that speaks to the original question about
whether this "puts limitations on types of statistical analysis
tests conducted."

In a word, mainly, "No."  You will use ordinary ANOVA or
Pearson correlations for analyzing the scale totals, or for
analyzing single items if you want to pursue single items.
If you have large enough Ns, you might look into developing a
scale by IRT or Rasch methods.

Now, I am going to assume that you might have heard of some
bad advice that was once promulgated by a few non-statisticians
in psychology and education.  That was about 40 years ago,
when interest first grew in various so-called "robust" techniques. 
The bad message has not been completely stamped out.
What you certainly do *not* want to do is retreat to rank-
based "non-parametric" statistics, which are generally messed
up by the excess of ties.  (Also, using ranks costs you the ability
to discuss simple means).

--
Rich Ulrich

> Date: Mon, 17 Oct 2011 10:13:57 -0700

> From: [hidden email]
> Subject: A 4 point Likert scale
> To: [hidden email]
>
> Hi
>
>
> I intend to use a 4 point Likert scale format in my survey.
>
> I want to know if this puts limitations on the type of statistical analysis
> tests conducted?
>

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