Chapter 16
Semantic Differential
Scaling:
A How To Do It Guide
Semantic differential methods of scaling are a recently introduced method of attitude
assessment. In 1967, Osgood, Suci and Tannenbaum introduced the method in their book "The
Measurement of Meaning." Although the original purpose of semantic differential was not
necessarily the assessment of attitudes, the procedure was well adapted for attitude assessment.
A semantic scale is composed of polar opposite adjectives separated by a five to seven
point rating scale, like this:
Bad ___ ___ ___ ___ ___ ___ ___ Good
To utilize the scale, the subject would be given an attitude referent. The attitude referent would
be perhaps an object or event in the subject's environment, for example, the referent "mother."
The subject's task would be to rate the referent "mother" on the seven point scale from bad to
good. If the subject selected the middle space then it is advanced that the evaluation would be
neutral. However, if the subject selected one of the spaces closer to the "good" end of the scale,
then his/her evaluation was seen as a positive endorsement of the referent "mother".
Conversely, selection closer to the "bad" end of the scale was seen as a negative endorsement.
If you assigned numerical values of 1 through 7 to the various spaces on the scales, then a neutral
score would become a 4, a very positive endorsement a 7, and a very negative endorsement a 1.
To utilize these types of scales to measure an attitude it is proposed that a number of
semantic scales be utilized. For example, we might assess a subject's attitude toward "mother"
by using the following semantic scales:
Bad
Unfriendly
Sad
Cruel
Dirty
Foolish
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Please rate your Mother
___ ___ ___ ___ ___
___ ___ ___ ___ ___
___ ___ ___ ___ ___
___ ___ ___ ___ ___
___ ___ ___ ___ ___
___ ___ ___ ___ ___
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Good
Friendly
Happy
Kind
Clean
Wise
The score on our attitude toward mother scale would be calculated by adding up the
numerical values of the scales endorsed. The maximum score would be 42 and the minimum 6.
To guard against the subjects developing some type of response bias (responding to all sales with
the same ratings, leaving the impression that the subject may not have read the individual scales)
the polarity of some of the scales could be reversed.
Osgood, et al had their subject rate various attitudinal referents on a large number of
semantic scales. These data were then analyzed by factor analytic procedures to determine
possible common factors which could be identified in the collection of semantic scales. (Very
simply, factor analysis identifies clusters of scales.) His analysis indicated that the majority of
the semantic scales tended to fall into three principle factors. These principle factors were
evaluation, potency, and activity. I have selected from the list of semantic scales presented in
their book those scales which appear to load highest on each of the three factors.
Semantic Scales Identifying the Factors of
Evaluation, Potency, and Evaluation*
Evaluation
Potency
Activity
Good-Bad
Hard-Soft
Active-Passive
Kind-Cruel
Strong-Weak
Fast-Slow
Wise-Foolish
Heavy-Light
Difficult-Easy
Beautiful-Ugly Masculine-Feminine
Hot-Cold
Happy-Sad
Deep-Shallow
Motivated-Aimless
Candid-Deceitful Potent-Impotent
Moving-Still
Sociable-Unsociable Severe-Lenient
Excitable-Calm
Friendly-Unfriendly Domineering-Lax
Alive-Dead
Willing-Unwilling Brave-Cowardly Emotional-Unemotional
Honest-Dishonest
Large-Small
Complex-Simple
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* The left hand adjective identifies the positive end of the semantic
scale.
Using semantic scales from each of the factor groupings, a dimensional representation of
an attitude is made possible. For example, a measure of the attitude referent can be made on the
factors of evaluation, potency and activity. To demonstrate such an instrument, suppose that our
attitude toward mother questionnaire was composed of the following semantic scales (notice that
3 scales were selected from each factor grouping from the listing above).
Good
Soft
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Please rate your mother
___ ___ ___ ___ ___
___ ___ ___ ___ ___
Active
Cruel
Strong
Slow
Wise
Heavy
Ease
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Bad
Hard
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Passive
Kind
Weak
Fast
Foolish
Light
Difficult
Notice that I have reversed the polarity of every other item, so that the first item would
be scored from 7 to 1, the second item from 1 to 7, etc. Also notice that I have alternated the
scales from the evaluation factor first, potency factor second, and activity factor third. This
sequence of presentation is repeated through the questionnaire. Now, suppose that we
administer our questionnaire to a subject and we obtain the following responses:
Good
_X_
Please rate your mother
___ ___ ___ ___ ___
Soft
Active
Cruel
Strong
Slow
Wise
Heavy
Ease
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_X_
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_X_
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_X_
_X_
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_X_
_X_
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_X_
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_X_
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Bad
___
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Hard
Passive
Kind
Weak
Fast
Foolish
Light
Difficult
To determine the subject's scores we will need to sum the values of the evaluation,
potency, and activity scales as follows:
Evaluation
Value
Good-Bad
7
Cruel-Kind
6
Wise-Foolish
Total
7
20
Potency
Soft-Hard
Strong-Weak
Heavy-Light
Total
3
5
4
12
Activity
Active-Passive
Slow-Fast
Easy-Difficult
Total
5
3
4
12
It has been suggested that to obtain an attitude score only the evaluation factor scales
should be considered. Using this suggestion, our subject would have a score of 20, out of a
possible score of 21. (Minimum possible score of 3 and neutral score of 12.) This magnitude of
score would indicate a very favorable attitude toward "mother". However, on the potency and
activity factors our subject placed at the neutral point. In short, our subject rated the referent
"mother" very high in evaluation, neutral (neither positive or negative) on the concepts of
potency and activity.
I have often seen researchers derive their attitude score by summing all of the semantic
scales. In our example, the total score would have been 44, with the highest score being 63 and
the lowest 9 (neutral point of 36). Using this procedure our subject would have a slightly
positive attitude toward the referent "mother".
I do not recommend the total scoring procedure and recommend that the data be scored to reveal
the three factor sub-scores. I feel that the factor scoring procedures provides additional
descriptive information with minimal additional computations.
Critique of the Semantic Differential Scaling Process
Our critique of the semantic differential scaling process will focus on 7 characteristics:
zero point, equality of units, unidimensionality of items, usunidimensionalityof scale, reliability,
content validity, and ease of application.
In terms of a zero point, semantic differential methods provide a well defined zero. The
zero point is a number of scales used times 4 (the neutral point of a given scale). In terms of our
five point compliance index, ranging from 1 - no compliance to 5 - very good compliance, I
would rate semantic differentials as a 4.
The second criteria was equality of units. On this characteristic our semantic scaling
process does not fare as well. Although there is some evidence that some of the scales
contribute uniquely to the underlying factors, there is no conclusive proof that the contribution is
equivalent across semantic scales. Therefore, on our five point compliance index I would have
to give semantic differential scaling a 2.
In terms of unidimensionality of items, the semantic differential scaling process performs
satisfactorily. Each of the semantic scales represents a continuum anchored by polar opposite
adjectives and appearing to assess one content. In terms of our compliance ratings, I would
have to give semantic differential methods a 4.
With respect to unidimensionality of scale, semantic differentials can pose some
interesting problems. If the attitude score is developed by considering the three factor
components of evaluation, potency and activity, then there is good unidimensionality.
However, if a total attitude score is generated by combining the three factor components then we
would have poor unidimensionality. Overall I rate semantic differentials as a 3 on our
compliance index.
Like Thurstone scaling, semantic differential processes does not include a built-in method
of assessing reliability. Therefore, on our compliance scale I would have to give semantic
differential scaling a 1 for reliability.
The content validity of the semantic differential is not as rigorous as the previous
methods of attitude scale development (Likert and Thurstone). This contention is not surprising
since the original purpose of the semantic differential was not specifically attitude assessment (it
has been adapted to attitude measurement).
On our compliance ratings I would have to give semantic differentials a 3 in terms of
compliance.
Our final criteria for the evaluation of an attitude questionnaire was ease of application.
This is the one area in which semantic differential surpasses all other attitude assessment
procedures. I will assign a compliance rating of 5.
Following is a summary of our compliance ratings.
Compliance Ratings of Semantic Differentials
Criteria
Rating
Zero Point
Equality of Units
Unidimensionality of Items
Unidimensionality of Scale
Reliability
Content Validity
Ease of application
4
2
4
3
1
3
5