Improving Questionnaire Discrimination with Coefficient δ
Author Information
Author(s): Matthew Hankins
Primary Institution: King's College London, Department of Psychology
Hypothesis
Can a new coefficient δG improve the discrimination ability of questionnaires in clinical research?
Conclusion
The new coefficient δG effectively distinguishes between the discrimination capabilities of different scoring methods for questionnaires.
Supporting Evidence
- The reliability of both scoring methods was high, with Cronbach's alpha above 0.88.
- Dichotomous coding resulted in a lower discrimination index (δG = 0.73) compared to polytomous coding (δG = 0.96).
- More than half of the sample scored the same on the dichotomous scale, indicating poor discrimination.
Takeaway
This study shows that using a new method to score questionnaires can help tell the difference between people’s health better than older methods.
Methodology
The study derived a general formula for coefficient δG and applied it to data from the GHQ-12 questionnaire.
Limitations
The study primarily focuses on the GHQ-12 and may not generalize to all types of questionnaires.
Participant Demographics
Participants were from the general population in the UK.
Statistical Information
P-Value
< 0.001
Confidence Interval
95% CL: 0.956, 0.959
Statistical Significance
p < 0.001
Digital Object Identifier (DOI)
Want to read the original?
Access the complete publication on the publisher's website