Demonstrating Construct Validity of the American Board of Physical Medicine and Rehabilitation Part I Examination: An Analysis of Dimensionality
Bibliographic record
Abstract
BACKGROUND: Ideally, high-stakes examinations assess 1 dimension of medical knowledge to produce precise estimates of a candidate's performance. It has not been reported whether the American Board of Physical Medicine and Rehabilitation Part 1 Certification Examination (ABPMR-CE-1) is unidimensional or not. OBJECTIVE: To examine the ABPMR-CE-1 to measure how many dimensions it assesses. DESIGN: Retrospective observational study. SETTING: We assessed examination results from the 2015 ABPMR-CE-1. PARTICIPANTS: A total of 489 deidentified candidates taking the 2015 ABPMR-CE-1. METHODS: A 1-parameter Item Response Theory (IRT) measurement model was utilized. A Principal Components Analysis (PCA) of standardized residual correlations was used to detect multidimensionality. MAIN OUTCOME MEASURE: Number of primary dimensions reflected in the 325 test questions. RESULTS: The results of the dimensionality analysis indicated that the ABPMR-CE-1 examination is highly unidimensional from a psychometric perspective. Expert content review of the substantive content of small contrasting clusters of questions provided additional assurance of the unidimensional nature of the examination. CONCLUSIONS: The ABPMR-CE-1 appears indeed to measure a single construct, which suggests a sound structure of the examination. It closely approximates the assumption of statistical unidimensionality. LEVEL OF EVIDENCE: Not applicable.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.011 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.002 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".