Reliability of a knowledge of AIDS scale a replication

Area of Science:

• Psychometrics
• Psychology
• Health Sciences

Background:

• Assessing the reliability of measurement instruments is crucial for valid research.
• The Zimet's knowledge of AIDS scale is a tool used to measure knowledge about Acquired Immunodeficiency Syndrome.
• Different methods exist for estimating the reliability of psychometric scales, each with its own assumptions and applications.

Purpose of the Study:

• To evaluate the reliability of the Zimet's knowledge of AIDS scale using various split-half methods.
• To compare the effectiveness of content-matched split-half reliability estimation against traditional methods.
• To determine the most suitable reliability estimation technique for this specific scale and population.

Main Methods:

• Anonymously administered Zimet's knowledge of AIDS scale to 2,209 university students.
• Calculated reliability using the odd-even Spearman-Brown split-half method.
• Calculated reliability using a content-matched split-half method and Cronbach's alpha coefficient.

Main Results:

• The odd-even Spearman-Brown split-half reliability coefficient yielded lower estimates than the other methods.
• The content-based split-half coefficient provided higher reliability estimates compared to the odd-even method.
• Cronbach's alpha coefficient was comparable in reliability estimates to the content-based Spearman-Brown method.

Conclusions:

• Content-matched split-half reliability and Cronbach's alpha are more robust estimators for the Zimet's knowledge of AIDS scale.
• The traditional odd-even split-half method may underestimate the true reliability of this scale.
• Researchers should consider content-matching or Cronbach's alpha for reliable measurement of AIDS knowledge.