How well is each learner learning? Validity investigation of a learning curve-based assessment approach for ECG interpretation

Learning curves can support a competency-based approach to assessment for learning. When interpreting repeated assessment data displayed as learning curves, a key assessment question is: “How well is each learner learning?” We outline the validity argument and investigation relevant to this question, for a computer-based repeated assessment of competence in electrocardiogram (ECG) interpretation. We developed an on-line ECG learning program based on 292 anonymized ECGs collected from an electronic patient database. After diagnosing each ECG, participants received feedback including the computer interpretation, cardiologist’s annotation, and correct diagnosis. In 2015, participants from a single institution, across a range of ECG skill levels, diagnosed at least 60 ECGs. We planned, collected and evaluated validity evidence under each inference of Kane’s validity framework. For Scoring, three cardiologists’ kappa for agreement on correct diagnosis was 0.92. There was a range of ECG difficulty across and within each diagnostic category. For Generalization, appropriate sampling was reflected in the inclusion of a typical clinical base rate of 39% normal ECGs. Applying generalizability theory presented unique challenges. Under the Extrapolation inference, group learning curves demonstrated expert–novice differences, performance increased with practice and the incremental phase of the learning curve reflected ongoing, effortful learning. A minority of learners had atypical learning curves. We did not collect Implications evidence. Our results support a preliminary validity argument for a learning curve assessment approach for repeated ECG interpretation with deliberate and mixed practice. This approach holds promise for providing educators and researchers, in collaboration with their learners, with deeper insights into how well each learner is learning.