Case Study

Evaluate the developer's claim regarding the validity of this screening tool. Determine whether a researcher should adopt this scale for a study measuring overall Conscientiousness, and justify your decision based on the definition of the construct.

Case context: A psychometrician is developing a brief screening tool for Conscientiousness to use in longitudinal academic research. The screening tool consists of 12 items. An analysis of the items shows that 9 items measure 'order' (organization) and the remaining 3 items measure 'achievement striving'. The developer claims that because the scale has exceptionally high internal consistency, it is a highly valid measure of the broad dimension of Conscientiousness. However, the scale contains no items measuring competence, dutifulness, self-discipline, or deliberation.

Question: Evaluate the developer's claim regarding the validity of this screening tool. Determine whether a researcher should adopt this scale for a study measuring overall Conscientiousness, and justify your decision based on the definition of the construct.

Sample answer: The developer's claim is invalid, and the researcher should not adopt this scale. High internal consistency (reliability) does not guarantee validity. Conscientiousness is a broad trait defined by six specific facets: competence, order, dutifulness, achievement striving, self-discipline, and deliberation. By containing items that only measure 'order' and 'achievement striving', the scale completely ignores competence, dutifulness, self-discipline, and deliberation. Consequently, the scale lacks content validity and fails to measure the broad dimension of Conscientiousness. To be valid, the scale must be revised to measure all six facets.

Key points:

  • Distinguish between high internal consistency (reliability) and validity.
  • Identify that the scale lacks content validity because it does not cover the full construct.
  • List the omitted facets: competence, dutifulness, self-discipline, and deliberation.
  • Recommend rejecting the scale for measuring overall Conscientiousness due to its narrow focus on order and achievement striving.

Rubric: The evaluation must correctly state that the developer's claim is flawed because reliability (internal consistency) is distinct from validity. The justification must highlight that the scale lacks content validity because it omits four of the six facets of Conscientiousness (competence, dutifulness, self-discipline, and deliberation) required to measure the broad construct.

0

1

Updated 2026-05-26

Contributors are:

Who are from:

Tags

KPU

Research Methods in Psychology - 4th American Edition @ KPU

Related