[NIFL-HEALTH:3497] likert scales

From: Holly Avey (havey@emory.edu)
Date: Mon Dec 17 2001 - 11:17:48 EST


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From: Holly Avey <havey@emory.edu>
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Subject: [NIFL-HEALTH:3497] likert scales
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A few weeks ago I posted a question about using likert scales for
low-literacy readers.  Specifically, I was asking about the answers to
these questions violating normal distribution assumptions.  I had a few
requests to post the answers to the listserve, so here they are below (I
have also copied my original question at the bottom).

The main themes for the answers seem to be:
1) Likert scales tend to have answers that cluster on either end anyway,
and that's okay
2) Write out the answers whenever possible and position them vertically
3) Whether or not you use labels along with the numbers, how you ask
people to indicate their answers, and how many points there are on the
scale can all affect the answers you receive
4) Avoid the use of likert scales
5) If you have the opportunity in an education class, use the scale as
an activity with people standing in different parts of the room to
correspond with different answers, followed by a discussion and
opportunity to change positions

Thanks to all who responded!!

-- Holly

P.S.  I'm afraid I was unable to open a message from Carol Barks Bani
regarding this topic, so this summary does not include her response.

***************
The normal distrubution is made-up.  Having answers cluster at either
end of a likert scale is completely OK.  There are a lot of issues
around the "normal" distrubtion.  Others more test savvy can probably
fill in with more info.

Example:  a lot of consternation at Harvard about grade inflation.  Who
knows, it is possible for all students to get A's, it doesn't have to be
"grade inflation."
***************
There is a strong tendency for Likert scale responses to cluster at the
ends anyway.  I don't suggest using Likert scales.  Even though it is
more work, write out the choices vertically:
1.  I like school.
a.  Always
b. almost always
c. usually
etc.
****************
I remember hearing Rima Rudd (Harvard literacy expert, and excellent
speaker if you ever have the chance).  She said that materials for low
literacy adults are often longer in order to be clear.  Writing out
responses as Kathleen suggests is a great idea
****************
When using Likert-type scales with low-literacy readers, do you label
the end-points of the scale (e.g., "a lot, very true" at one end and
"not at all, false" at the other)? Do you label the mid-point? Or do you
simply give instructions that say something like "1=least, 7=most"?

This may well have something to do with the various successes people are
reporting.

Also, are you using 5-point or 7-point scales? Asking people to circle a
spot on a scale, circle a number, or write a number in a blank?

All these may also be relevant.
****************
With many low literacy readers, it isn't subtle variations that are the
problem, but the fact that a likert scale was used to begin with.
 Also, rarely will a low-literacy reader make the effort to read the
directions.
***************
We have used the likert scale in a different way for low-literacy
students in adult education classes. We post signs on either side of a
wall that say "I strongly agree" and "I strongly disagree". In the
middle is a sign that says "not sure". (Or you could use "always/never"
or whatever other responses). We read statements (for example: "All
women over 40 should get a mammogram every year.") and the people go and
stand along the wall in the place that corresponds with how they would
answer, either under a sign or in between somewhere. Then we have
volunteers say why they are standing where they are, and a discussion
begins. Some people choose to move to a different spot in response to
the discussion.

Obviously this would not work for research or in a medical setting, or
other of the ways you use these scales. But in an education class, where
the goal is discussion and learning, rather than collecting statistics,
it is a fun and engaging way to use the likert scale.
*****************
My original question:

I recently tried to analyze some data I have been collecting from a
low-literacy population, and I ran across an issue I suspect others
already know about and have researched.  I attempted to write the survey
questions for my pre-test at
an appropriate readability level, based on general assessments of our
patient population a few years ago.  Many of the questions featured
likert scales for answer options.  When I began to analyze the data, I
discovered that it violated
normal distribution assumptions.  Specifically, the data seemed to
cluster at the extreme answer options.  My suspicion is that people with
low literacy may be more likely to choose extreme options on likert
scales, possibly because the
subtle variations between the choices get a little confusing.  Does
anyone know if this phenomena has been tested empirically?  If so, could
you provide me with some references?  Any suggestions on how to address
this problem?  (Maybe only offer three choices instead of five, or throw
out all likert scales completely?)  It does pose quite a problem when
trying to use standardized instruments and compare results to other
population groups. . .
******************


Holly Avey, MPH
Health Educator, Office of Health Promotion
Grady Health System, Atlanta, GA
Ph: 404-616-7561, Fax: 404-880-9464, E-mail: havey@emory.edu



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