Introduction
Attitude measurement is a key component of psychological, marketing, and public relations research. The Likert Scale and the Semantic Differential Scale are two of the most widely used tools for measuring attitudes. While both try to measure perceptions, they differ in structure, interpretation, and usefulness. In this blog, their strengths, weaknesses, and theoretical implications from the Elaboration Likelihood Model (ELM) and the Theory of Reasoned Action (TRA) perspectives are explained.
Likert Scale
A Likert Scale measures attitudes by asking respondents to express their level of agreement or disagreement with a set of statements. The scale typically has between five and seven response levels from Strongly Disagree to Strongly Agree.
Example of a Likert Scale Question:
“How satisfied are you with the customer service at our store?”
1 - Very Dissatisfied 2 - Somewhat Dissatisfied 3 - Neutral 4 - Somewhat Satisfied 5 - Very Satisfied
The Likert Scale possesses numerous benefits in measuring attitudes. Standardization of the scale provides consistent measurable responses that are easily analyzable and comparable across groups and hence is extremely popular in application for surveys, customer response questionnaires, employee attitude surveys, and political surveys. For instance, employee attitude surveys may gauge morale by requesting, "I feel valued in my workplace," and political polling may gauge public opinion regarding policies, such as "The new tax law is beneficial to middle-class families." It can also be used by business companies to track service quality by asking customers, "How do you rate our service? " The Likert Scale, however, has drawbacks too. It is prone to social desirability bias, where respondents select responses that they think are more socially acceptable, and central tendency bias, where individuals select middle responses instead of expressing strong opinions.
Semantic Differential Scale
The Semantic Differential Scale assesses attitudes on a range between two bipolar adjectives (e.g., Good–Bad, Strong–Weak). Respondents rate their perception on a scale, typically with seven points.
Example of a Semantic Differential Scale Question:
“How would you describe your experience with our online shopping platform?”
Convenient — — — — — — Inconvenient
Fast — — — — — — Slow
Intuitive — — — — — — Confusing
The Semantic Differential Scale possesses several strengths in attitude measurement. It provides revealing information by measuring subtle emotional and perceptual differences that would perhaps not be picked up by a Likert Scale. This flexibility allows it to measure a wide range of experiences, from products to brand reputation. Businesses, for example, can measure their positioning on scales like "Trendy – Outdated" or "Affordable – Expensive," while UX researchers can utilize "Confusing – Intuitive" to measure how easy it is to navigate a website. Even public figures can be measured on traits like "Trustworthy – Untrustworthy" in political image measurement. Yet, among the primary criticisms leveled against the Semantic Differential Scale is the fact that it is not standardized, making interpretation harder. Additionally, cultural and individual differences can influence the perception of the adjective pairs by the respondents.
Theoretical Application: ELM & TRA
Likert Scale
ELM Perspective: Highly involved respondents (central route processing) will more likely critically think through statements, which leads to more accurate responses. Low involvement (peripheral route processing) respondents might select responses without deep thinking.
TRA Perspective: Social desirability bias can influence responses, as the respondent will answer in a socially desirable manner. For example, if asked about diversity in the workplace, a respondent will check "Strongly Agree" regardless of his/her personal opinion.
Semantic Differential Scale
ELM Perspective: Since this scale involves intuitive judgments, high-involvement respondents will think through adjectives carefully, while low-involvement respondents will either tick off at random or check middle points.
TRA Perspective: Since the scale does not pose direct questions (in contrast to Likert Scales), it might minimize social desirability bias. Having said that, social and cultural norms could still affect answers—for instance, an individual from a conservative culture could rank "Modern – Traditional" differently than an individual from a liberal environment.
Reflection
This analysis has deepened my understanding of attitude scales and their role in measuring perceptions. Likert Scales offer structured, measurable data but are vulnerable to social desirability bias and neutral response tendencies. Semantic Differential Scales capture emotional nuances but present challenges in standardization and interpretation. Both scales are influenced by receiver involvement (ELM) and social norms (TRA), making it essential for researchers to design surveys carefully and interpret results critically. Moving forward, I will approach attitude measurement more thoughtfully, recognizing the strengths and limitations of different scales in shaping meaningful insights.
References
Simply Psychology. (n.d.). Semantic differential scale: Definition, questions, examples. Retrieved from https://www.simplypsychology.org/semantic-differential.html
Simply Psychology. (n.d.). Likert scale questionnaire: Examples & analysis. Retrieved from https://www.simplypsychology.org/likert-scale.html
