This document discusses scaling methods in research, specifically Likert scales. It provides details on different types of rating scales including Likert scales, semantic differentials, graphic rating scales and itemized rating scales. It discusses pros and cons of Likert scales and comparisons of rating scales of different lengths in terms of reliability, validity, and response preference. The document recommends using a 7-point Likert scale if a rating scale is needed, or a 6-point scale if respondents need to be directed to one side. It provides references to other works by the author on related research methodology topics.

1. Research Methods;
Scaling Methods
Dr. HamedTaherdoost
Founder of Hamta Group
OBS Tech Limited
Hamta Academy
Senior Member of IEEE
(www.hamta.org)

2. HELLO!I AM HAMEDTAHERDOOST,
the award-winning leader and R&D Professional,andthe founder of
Hamta Group.
I haveover two decades of experience in both industry andacademic
sectors,and I have been highly involvedin development of several
important projects in different industries .
I havebeen an activemultidisciplinary researcher working with
researchers fromvarious disciplines andhavebeen actively engagedin
several academic and industrial research projects.
My views on scienceandtechnology havebeen publishedin top-ranked
scientific publishers such as Elsevier,Springer,Emerald, IEEE,IGI Global,
Inderscience,Taylor and Francis andhavepublished over120 scientific
articles,seven book chapters as well as six books in the field of
technology andresearch methodology.
I am Senior Member of IEEE, IASED, IEDRC,Working group member of
IFIP TC 11, Member of CSIAC, & ACT-IAC.
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3. Survey / Questionnaire
One of the important research tool is questionnaire.
Decision makers and researchers across all academic and industry
sectors conduct surveys and questionnaires to uncover answers to
specific, significant questions.
Surveys can be an effective tools for data collection required for
research and evaluation.
In order to develop a survey/questionnaire, first the researcher should
decide how to collect the required data. In this regard, scaling is the
branch of measurement that involves the construction of an
instrument.
3Survey VS Questionnaire ?!

4. Scaling Methods
Scaling is the process of generatingthe continuum, a continuous
sequence of values, upon which the measured objectsare placed.
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5. “
Rating Scales;
Raters evaluate a person, object or other
phenomenon at a point alonga continuum orin
a category. A numerical value is then assigned to
this point or category.
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Attitude Scales;
It measures an individual’spredispositiontoward
any person, object or other phenomenon. These
scales differ from rating scales in that they are
generally morecomplexand multi-itemscales.
Graphic Rating Scales;
Raters mark or indicate in another fashion, how
they feel on a graphic scale of some sort.
ItemizedRatingScales;
Raters select one of the limited numbers of
categories that are ordered in some fashion. The
number of categories is usually between 2 and
11.
ComparativeRatingScales;
Raters judge against some standard or some
other person, object or other phenomenon.
Likert Scale;
Respondent indicates degree of agreement and
disagreement with a variety of statements
about some attitude, object, person or event.
SemanticDifferential;
Respondent indicates how strongly he/she holds
an attitude. These scales include a progression
from one extreme to another .

6. Likert Scale
The original scaleincludedfive
symmetrical andbalanced points,
during theyears it has been used
with different measurement range in
terms of number of responseoptions
from 2-11 points.
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One of themost fundamental and
popular scaling methodused in
sociology,psychology,information
system,politics, economy and
other fields is Likert scale.
Likert scale has been
developed in 1932as part of
doctoral dissertation of
Rensis Likert (Likert, 1932).
.
This scale as a psychometric tool,includes a set of
statements of research study’s hypothesis.
Participants in thesurvey areasked
to state their level of agreement with
thosegiven statements from strongly
agree to strongly disagree.
LIKERT

7. Likert Scale; Pros and Cons
• Liker scale is simple to construct and likely to produce a highly reliable scale.
• It is easy to read and complete.
• Validity may be difficult to demonstrate and there is a lack of reproducibility.
• Another weakness of Likert scale is that participants may avoid extreme
response categories and this will cause central tendency bias.
• Also participants may response the statements either agree or disagree in
order to please the experimenter (acquiescence bias).
• Social desirability bias is another weakness of the Likert scale which may
happen as participants may not be honest instead try to portray themselves in
a more socially favorable light.
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8. Comparison Rating Scales Of Different Lengths
Reliability
Number of response categories
does not materially influence
the cognitive structure derived
from the results. Highest
reliability is for 7 to 10 and the
lowest is for 3-point.
Odd or Even
Scales with midpoint have lower
reliability, it will facilitate to
collect more useful data.
However it may discourage
respondents from taking side in
one direction.
Validity
9-point has the highest creation
validity although scores from
five scales above have very
similar criterion validity. Scales
over six have higher convergent
validity.
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Visual Analog
There is no psychometric
advantage for visual analog
scales rather than traditional
rating scales. However this may
affect respondents choice.
Response Preference
From the perspective of “ease of
use'', “quick to use” and “express
feelings adequately, ”2 & 3
points are quick, 5&7&10 are
easier to use though the 7-
points are more accurate,
interesting and ambiguous.
The effects of rating scales have been investigated in terms of psychometric quality
criteria and systematic measurement error .

9. SO!
Taken as a whole using
of seven-point rating
scale is suggested and if
there is a need to have
respondent to be
directed on one side,
then six-point scale is
the most suitable.
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10. “HamedTaherdoost,2019,What Is theBest Response Scale for Survey and Questionnaire
Design;Review of Different Lengths of Rating Scale / AttitudeScale / Likert Scale,
International Journal ofAcademic Research in Management,Vol. 8, No. 1, Page:1-10,.
HamedTaherdoost,2017,Measurement andScaling Techniques in Research
Methodology;Survey / QuestionnaireDevelopment,International Journal ofAcademic
Research in Management,Vol. 6, No. 1, Page: 1-5.
HamedTaherdoost,2016,Validity and Reliability of the Research Instrument;Howto
Test the Validation of a Questionnaire/Survey in aResearch,International Journal of
Academic Research in Management,Volume. 5, No. 3, Page: 28-36.
HamedTaherdoost,2016,Sampling Methods in Research Methodology;How to Choose
a Sampling Techniquefor Research,International Journal ofAcademic Research in
Management,Volume. 5, No. 2, Page:18-27.
HamedTaherdoost,2014,Exploratory Factor Analysis;Concepts andTheory, Advances in
Applied and PureMathematics,Page:375-382.
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More Read …

11. THANKS!
ANY QUESTIONS?
You can find me at:
in/hamed.taherdoost
RG.net/hamed.taherdoost
orcid.org/0000-0002-6503-6739
hamed@hamta.org
hamed.taherdoost@gmail.com
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