What you do here
Past papers and generated papers in the shape your exam is actually set in — its command terms, its mark allocations, its timing. The retrieval you practise is the retrieval you will be asked for, which is the whole argument for it existing separately from the Vault.
How it works
Generated questions are scored against how students actually answer them: options nobody ever picks, answer keys that look wrong, items that turned out too easy. Under a sample-size floor we call an item provisional instead of guessing.