Ace
Short answer: an AI quiz generator from a PDF can save you hours of writing questions, but research has found errors in a large share of AI-written practice questions, even when the AI was given the source text. Before you revise with one, check that it writes questions only from your file, shows where in the file each answer comes from, lets you pick chapters, and asks more than recognition-style questions.
Why quiz yourself from a PDF at all?
Because testing yourself is one of the best ways to learn, and most course material arrives as PDFs and slides. Roediger and Karpicke (2006) found that students who took recall tests on a passage remembered much more a week later than students who used the same time to reread it. The catch has always been that writing good questions takes ages. An AI quiz generator solves the time problem, which is why there are now so many of them.
The new problem is accuracy.
How often are AI-written questions wrong?
More often than most students would guess. Two studies in medical education give a sense of it:
- Ngo and colleagues (2024) uploaded author-written text to ChatGPT 3.5 and asked for 60 multiple-choice questions with explanations. Only 32% (19 of 60) came out with correct questions, answers and explanations. Another 25% had answers that were wrong or misleading. Note that the AI had the source text in front of it.
- Camarata and colleagues (2025) had ChatGPT write board-exam-style practice questions on renal physiology for second-year medical students. Independent experts found item-writing flaws in 49% of the questions and factual or conceptual errors in 22%. They concluded the approach was workable only with supervision from a subject expert.
Newer models do better than ChatGPT 3.5, and these studies tested general chatbots rather than purpose-built tools. But the lesson holds: an AI-written question can be confidently wrong, and as a student you are the person least able to spot it, because you are still learning the topic.
Wrong practice questions are worse than none. Butler and Roediger (2008) showed that multiple-choice tests can leave students believing the wrong options (the "lures") they picked. Feedback with the correct answer reduced that effect. So a quiz tool should make it easy to see the correct answer and why.
Six things to check in any AI quiz generator
- Does it write from your file only? If the tool mixes in general knowledge, you can get questions on things your course never covered, or answers that disagree with your lecturer's version. Look for a clear statement that questions come from the uploaded material.
- Does it show the source for each answer? The best check is the sentence in your own file that backs the answer. If you can't see where an answer came from, you can't check it.
- Does it check its own questions? Some tools check each answer against the source and drop questions that fail. Others show you whatever the model writes. Ask, or test it on a chapter you know well.
- Can you choose chapters? A 200-page PDF turned into one quiz is shallow on every topic. You want to quiz this week's chapter, or your weak chapters, separately.
- Are the questions only recognition? Multiple choice is fine, but questions where you type the answer or put steps in order make you recall rather than recognise. A mix is better for exams.
- Does it handle the formats you have? PDF is standard. Check slides, Word documents and lecture videos if you use them. Note that many tools read only text, so diagrams and charts in your file may be ignored.
How to use one well
- Test it on a chapter you know. Ten minutes on a familiar topic tells you more about a tool's accuracy than any review.
- Answer before you look. Don't scan the options for the one that looks familiar. Try to answer in your head first.
- Read the source when you're wrong. The fix for a wrong answer is the original sentence, not a guess about why.
- Flag bad questions. If a question seems off, check the source. If the question is wrong, skip it and don't learn from it.
- Space it out. Quiz the same chapter again a few days later. Our guide to turning lectures into quizzes covers a full routine.
The checklist above is what Ace was built around. It turns PDFs, PowerPoint slides, Word documents, ePub books, plain text and YouTube lecture links into practice questions written only from that material. Every answer is checked against the file, questions that fail the check are dropped, and under each answer you see the sentence from your file that backs it. You pick the chapters, and question types include multiple choice, type-the-answer, put-the-steps-in-order and label-the-diagram, depending on what the material contains. See how it works.
Frequently asked questions
Are AI-generated quizzes accurate?
Not always. Studies of ChatGPT-written practice questions found factual errors in 22% in one study and wrong or misleading answers in 25% in another. Use tools that show the source for each answer, and check anything that looks off.
Can ChatGPT make a quiz from a PDF?
Yes. You can upload a PDF and ask for questions. Ask it to use only the PDF and to quote the passage behind each answer, and check those passages. Our guide to uploading a PDF to ChatGPT has prompts.
Is multiple choice good enough for revision?
It helps, especially with feedback, but questions that make you recall the answer yourself are stronger. A mix of formats is best.
Can an AI quiz generator read diagrams in my PDF?
Many tools work from the text only, so check before relying on one for diagram-heavy subjects.
Sources
- Ngo, A., Gupta, S., Perrine, O., Reddy, R., Ershadi, S., & Remick, D. (2024). ChatGPT 3.5 fails to write appropriate multiple choice practice exam questions. Academic Pathology, 11(1), 100099.
- Camarata, T., McCoy, L., Rosenberg, R., Temprine Grellinger, K. R., Brettschnieder, K., & Berman, J. (2025). LLM-generated multiple choice practice quizzes for preclinical medical students. Advances in Physiology Education, 49(3), 758–763.
- Butler, A. C., & Roediger, H. L. (2008). Feedback enhances the positive effects and reduces the negative effects of multiple-choice testing. Memory & Cognition, 36(3), 604–616.
- Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
