A major disadvantage of comparative scales would be which of the following?
A) Halo or carryover effects are reduced.
B) Respondents bring the same point of reference to a task.
C) The resulting data measures relative differences.
D) Only big differences between objects can be detected.
E) A researcher cannot generalize beyond the objects under study.
The correct answer and explanation is :
Correct Answer: E) A researcher cannot generalize beyond the objects under study.
Explanation:
Comparative scales are measurement tools in which respondents evaluate one object in relation to another rather than in absolute terms. Examples include paired comparison scales, rank order scales, constant sum scales, and others where preferences between items are directly compared.
While comparative scaling offers certain advantages—such as reducing some biases like halo effects and forcing clearer discrimination between alternatives—it comes with significant limitations. The most critical disadvantage, reflected in option E, is the lack of generalizability beyond the specific set of objects included in the study.
This limitation arises because comparative scales are inherently relative. The evaluation depends on the context of the other items in the set. For instance, if respondents are asked to rank five brands of soda, their ranking is valid only for that specific set of five. The introduction of a sixth brand might completely alter the results, making it impossible to extend conclusions or make inferences about preferences outside that group.
This constraint is especially problematic in market research or behavioral studies where generalizations to a broader population of products or services are often desired. For example, a company comparing only its own product against two competitors cannot assume the findings apply to the entire category, especially if key competitors were excluded.
In contrast, non-comparative scales (like Likert or semantic differential scales) provide absolute measurements, allowing researchers to evaluate each item independently. These are more suitable when the goal is to generalize findings or compare against broader benchmarks.
In summary, while comparative scales can produce more discriminative and sometimes more realistic responses, they are fundamentally restricted to the context of the study, making generalizability the major disadvantage—hence, option E is correct.