UWorld vs AMBOSS for Step 2 CK
Both question banks measured against the real exam scores of the students who used them, across 2,426 score reports from r/Step2.
Summary of the results
Among 2,426 score reports from r/Step2, 88% mention UWorld and 8% mention the AMBOSS Qbank; 1,972 and 48 of them pair a percent correct with a real exam score. The AMBOSS sample is smaller, so its estimates are less precise. The main results were:
- The same-student reports cannot establish which bank is harder because usage order and session settings were not consistently reported.
- A given percent correct maps to nearly the same Step 2 score on either bank. A 70% average maps to roughly 258 in both datasets.
- Total question count had almost no association with the final score across 472 reports. A focused second pass was associated with higher scores when first-pass accuracy was below 75%.
- The apparent benefit of a second qbank was a few points at mid-range UWorld accuracy and close to zero among students at 75% or above.
The same percentage maps to nearly the same score
Separate models were fit to each bank. From 60% to 80%, the Step 2 estimates remain within 3 points of each other.
| Qbank average | Step 2 if it is UWorld | Step 2 if it is AMBOSS |
|---|---|---|
| 60% | 250 | 248 |
| 65% | 254 | 252 |
| 70% | 258 | 256 |
| 75% | 262 | 261 |
| 80% | 266 | 265 |
These are fitted group averages. They reflect how each bank was used, including timing and session settings. The UWorld column is based on 1,972 reports and the AMBOSS column on 48.
The main predictor combines your qbank average with practice exams and assessment dates.
Every report on one chart
Each dot is one real score report; teal dots are AMBOSS Qbank averages and can be hovered or tapped for that person's full test list. The dashed line is the UWorld fit, the solid line the AMBOSS fit. They run nearly on top of each other.
Real scores by qbank average
UWorld (n = 1,972)
| UWorld average | Average Step 2 | Median | Reports |
|---|---|---|---|
| 50–54% | 243 | 244 | 56 |
| 55–59% | 248 | 249 | 182 |
| 60–64% | 252 | 253 | 337 |
| 65–69% | 256 | 257 | 465 |
| 70–74% | 260 | 261 | 397 |
| 75–79% | 264 | 264 | 297 |
| 80%+ | 268 | 269 | 229 |
AMBOSS Qbank (n = 48)
| AMBOSS average | Average Step 2 | Median | Reports |
|---|---|---|---|
| 60–69% | 250 | 252 | 19 |
| 70–79% | 260 | 261 | 19 |
| 80–89% | 270 | 270 | 6 |
AMBOSS rows are small samples, hence the wider bands; rows under 5 reports are hidden.
What the same-student reports show
Among the 36 students who reported a percent on both banks, the median gap was 0.5 points and 50% scored higher on AMBOSS. The reported percentages were therefore very similar.
Usage order limits the comparison. 10 of the 36 explicitly describe doing AMBOSS after UWorld, switching banks midway or saving AMBOSS for dedicated; none describe the reverse. That stated-order group averaged +7.5 points on AMBOSS relative to their earlier UWorld percentage. Score reports did not include session settings, so these data cannot measure the effect of including or excluding 5-hammer questions.
Because bank order and question settings differed or were missing, near-equal percentages cannot establish equal question-level difficulty. The separate percent-to-score mappings above are the result these reports support: the same reported percentage pointed to a similar final Step 2 score on either bank.
Does doing both banks help?
Students who used both banks averaged 261 against 257 for UWorld-only, a 4.2-point gap. Most of that difference reflects who completes two banks. Holding UWorld accuracy constant reduces the gap:
| UWorld average | UWorld only | Both banks | Difference |
|---|---|---|---|
| 55–64% | 250 | 255 | +5.1 |
| 65–74% | 258 | 261 | +3.9 |
| 75–89% | 265 | 266 | +0.8 |
The same pattern shows against practice exams: students who used both banks finished about 1.8 points above what their NBME scores predicted. The estimated difference associated with a second qbank is a couple of points, concentrated among students below the top accuracy band. At 75%+ on UWorld the difference is +0.8 points, too small to distinguish from sampling variation. Finish and review one bank first; add the second only if your accuracy has plateaued and the calendar allows it.
Question volume and final scores
Combine each report's completion percentages with the banks' sizes (about 4,300 UWorld and 3,400 AMBOSS questions) and you get total questions completed for 472 reports. The correlation with the final score is r = 0.02, which is effectively zero in this dataset.
| Questions completed | Average Step 2 | Median | Reports |
|---|---|---|---|
| Under 1,500 | 257 | 258 | 63 |
| 1,500–2,500 | 256 | 257 | 98 |
| 2,500–3,500 | 256 | 258 | 177 |
| 3,500–4,300 | 258 | 257 | 80 |
| 4,300+ | 257 | 256 | 54 |
Students who completed 1,500 questions had similar final scores to those who completed 4,300 or more. Among students at 65–75% on UWorld, finishing under half the bank versus over 80% of it moved the average by about 2.1 points. By comparison, percent correct correlated with the final score at r = 0.57. Accuracy was associated with the final score; total volume was not.
Struggling students might complete more questions, which could hide a benefit of volume in the raw averages. Two checks did not support that explanation. Question volume barely relates to where students started (r = +0.08 against the earliest practice test taken 45+ days out, n = 148). Slightly stronger students completed slightly more questions, which would tend to favor the high-volume group. Improvement was also similar across volume groups: from the earliest test to the real exam, students under 1,500 questions gained +28 points on average while students past 4,300 gained +24, and comparing students who started from the same score, each additional 1,000 questions moved the final score by -0.5 points. Completion is self-reported, so this is not a controlled experiment. Within these reports, completing very large numbers of questions was not associated with additional improvement. Cover the content, review missed concepts, and use practice exams to measure progress.
Second-pass results depended on first-pass accuracy. Among students with the same first-pass accuracy, those who did a second pass of UWorld outscored single-pass students by +5.0 points when the first pass landed at 55–64%, by +3.4 at 65–74%, and by 0.0 at 75% and up (248 second-pass reporters). The comparison is between students who scored the same on their first pass, which reduces the effect of stronger students being more likely to repeat. The association was concentrated below roughly 75% first-pass accuracy. Above that level, additional qbank volume was not associated with higher scores.
Self-assessment comparison
Both companies also sell full-length self-assessments, which beat any qbank percentage as predictors. The table reports each assessment's typical calibrated error and its median difference from the real exam.
| Self-assessment | Reports | Typical error | Real exam vs test, median |
|---|---|---|---|
| UWSA 1 | 1,621 | ±6.6 | +14 |
| UWSA 2 | 1,773 | ±6.0 | +5 |
| UWSA 3 | 356 | ±6.0 | +17 |
| AMBOSS Self-Assessment | 561 | ±7.2 | +17 |
The AMBOSS SA underestimates by about as much as UWSA 1 and UWSA 3; UWSA 2 lands closer to the real score. Their calibrated single-test errors are within a point or two of each other. The AMBOSS Score Predictor had the lowest error among the third-party rows in the comparison. Conversion guides: UWSA 1, UWSA 2, UWSA 3 and AMBOSS SA.
Which should you use?
UWorld has the larger evidence base in these reports: 1,972 students listed a UWorld percentage, which makes its conversion more precise. This dataset cannot compare how well the two banks teach. AMBOSS may be preferable if you value its integrated library or have already completed UWorld during clerkships. Whichever bank you choose, review it carefully and use practice exams to track readiness. The free predictor takes your qbank average, whichever bank it came from, and weighs it alongside everything else.
Common questions
Is the AMBOSS Qbank harder than UWorld?
These reports cannot establish question-level difficulty. Percentages were nearly equal (median gap 0.5) among the 36 students reporting both banks, but 10 explicitly used AMBOSS after UWorld and session settings were not reported. A given reported percentage mapped to about the same final score on either bank.
What does 70% on the AMBOSS Qbank mean for Step 2?
The fitted average was about 256 on Step 2, compared with 258 for a 70% UWorld average. The AMBOSS estimate is based on 48 reports and is less precise.
Do I need to do both UWorld and AMBOSS?
Students who used both banks scored about 4 points higher on average. Much of that gap reflects differences between the students who used one bank and those who completed two. At the same UWorld percentage, the gap is about 4 points for mid scorers and less than a point for high scorers. Finish and review one bank before adding another.
How many practice questions are enough for Step 2?
Across 472 reports with completion data, total questions completed had no measurable relationship with the final score (r = 0.02). Students under 1,500 questions averaged the same as students past 4,300, and their improvement from the earliest practice test was similar. A focused second pass was associated with several additional points when first-pass accuracy was below 75%.
Which predicts Step 2 better, UWorld or AMBOSS?
Their correlations with the final score were nearly identical: r = 0.57 for UWorld and r = 0.58 for AMBOSS. The UWorld mapping is more precise because it is based on 1,972 reports, compared with 48 for AMBOSS. The main predictor gives more weight to practice exams because they predicted better than either qbank percentage.
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Charts & guides
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