Related Experiment Video
Updated: May 30, 2026

Advancing Dyslexia Assessment in Children Through Computerized Testing
Published on: August 16, 2024
An examination of the validity of EPSCALE using factor analysis
Daniel P Edgcumbe1, Jonathan Silverman, John Benson
1General Practice and Primary Care Research Unit, University of Cambridge, Cambridge, UK. contact@drdan.me
Objective:
To examine the validity and utility of the Explanation and Planning Scale (EPSCALE) instrument, a widely used scale for teaching and assessment of explanation and planning skills used by clinicians during the medical interview.
Methods:
Data obtained across 4 OSCE stations during medical student final MB examinations. Exploratory factor analysis, using a single factor and two factor models (based on prior theory) and a six factor empirical model, suggested by parallel analysis.
Participants:
124 medical students sitting final MB examinations at the University of Cambridge.
Results:
A single factor model represented a very poor fit. A two factor model with factors labelled 'Explanation' and 'Planning' produced an improved fit, but the best was seen with a six factor model, with factors which broadly corresponded to the domains of the Calgary-Cambridge guide.
Conclusions:
These factor models provide supportive evidence for the construct validity of EPSCALE.
Practice Implications:
EPSCALE can justifiably be used in the assessment of shared-decision making skills.
Related Concept Videos
Factorial Design
Compacting Factor test
The procedure begins by placing concrete into the upper hopper without any compaction. Once filled, the bottom door of this hopper is opened,...
Reliability and Validity
Theory of Attribution II: Kelley's Covariation Theory
Scaling
Expected Frequencies in Goodness-of-Fit Tests