How often do people check AI output before using it?
About four in ten AI users regularly use AI output without checking it, by their own account: 44 percent of AI-using employees across 47 countries do not verify its accuracy most of the time, and knowledge workers report no critical thinking on 41 percent of their AI-assisted tasks. 56 percent of AI-using employees say AI has caused a mistake in their work at least once.
- Medium confidence
- 4 primary sources
- 2023 to 2026
- Last checked
Every study on one scale
Chart values as text
- Scale: % used without routine checking. Shaded range: 41–44%.
- KPMG and Melbourne (2025): 42–44% of AI users
- Lee et al., Microsoft and CMU (2025): 40.7% of tasks
- Stack Overflow 2026 (2026): 9.6% use as-is
- Noy and Zhang, experiment (2023): 68% unedited (experiment)
Why medium confidence: Two independent creators with very different methods land on almost the same figure, one counting people and one counting tasks. Both are self-reports, which likely understate careless use, and the observed studies are small or older.
Sources
| Study | Creator | Year | Sample | Method | Figure | Link |
|---|---|---|---|---|---|---|
| Trust, attitudes and use of artificial intelligence: A global study 2025 | University of Melbourne and KPMG International | 2025 | 32,352 employed people in 47 countries, November 2024 to January 2025 | Online survey of employees who use AI at work, self-reported frequency | 56% verify AI accuracy most of the time or always, so 44% do not; 42% rely on output without evaluating it sometimes or more often (66% ever) “Two in three report relying on AI output without evaluating the information it provides” | mbs.edu ↗ |
| The Impact of Generative AI on Critical Thinking (CHI 2025) | Hao-Ping (Hank) Lee and colleagues, Microsoft Research and Carnegie Mellon University | 2025 | 319 knowledge workers using AI at least weekly, describing 936 real tasks | Online survey; for each task, whether the worker did any critical thinking such as verifying or editing | Critical thinking reported on 59.3% of tasks, so none on 40.7%; higher confidence in AI predicted less critical thinking “Our participants self-reported to have enacted critical thinking for 555 (59.29%) of the examples” | microsoft.com ↗ |
| 2026 Developer Survey: AI data | Stack Overflow | 2026 | 13,162 developers answering this question, June to August 2026 | Opt-in survey; what developers usually do with an AI answer, several answers allowed | 9.6% use AI answers as-is; 76.5% run the code, 63.9% compare it with the codebase “Only 10% use answers as-is.” | survey.stackoverflow.co ↗ |
| Experimental Evidence on the Productivity Effects of Generative Artificial Intelligence | Shakked Noy and Whitney Zhang (MIT) | 2023 | 444 college-educated professionals in an online writing experiment, early 2023 | Self-report plus observed activity on the platform; not participants' real jobs | 68% said they submitted ChatGPT's first output unedited, and were active for about 3 minutes after pasting it in “68% of treated participants report submitting ChatGPT’s initial output without editing it” | economics.mit.edu ↗ |
How many workers have made mistakes because of AI?
Between about a third and a half of AI users. 56% of AI-using employees across 47 countries say they have made a mistake in their work because of AI, and 31% say it happens sometimes or more often. In a small 2026 US poll, 30% said a wrong AI answer had caused a problem in their work. Noticing errors is more common still: 66% of developers report AI answers that are almost right, but not quite.
| Study | Creator | Year | Sample | Method | Figure | Link |
|---|---|---|---|---|---|---|
| Half of U.S. Workers Know They Would Be Personally Liable for a Wrong AI Answer | Kolmogorov Law, poll on Pollfish | 2026 | 500 employed US adults who use AI for work, September 2026, unweighted | Online poll commissioned by a law firm; treat as indicative | 30% say a wrong AI answer has caused a problem in their work; 65% do not always verify AI answers “a wrong or inaccurate AI answer has caused a problem in their work” | prnewswire.com ↗ |
| 2025 Developer Survey: AI | Stack Overflow | 2025 | 25,332 developers answering the frustrations question | Opt-in online survey, several answers allowed | 66% cite AI answers that are almost right, but not quite; 45.2% say debugging AI code takes more time “AI solutions that are almost right, but not quite” | survey.stackoverflow.co ↗ |
Do AI mistakes reach customers?
Sometimes. A quarter of IT leaders (25%) say AI mistakes have already hurt customers or clients, 23% that they cost the company money, and 16% that they seriously disrupted operations. Of employees who review colleagues' AI work, 79% regularly receive output that is low quality or contains errors.
| Study | Creator | Year | Sample | Method | Figure | Link |
|---|---|---|---|---|---|---|
| The Pulse of Work in 2026 | GoTo with Workplace Intelligence | 2026 | 1,250 knowledge workers and 1,250 IT decision-makers in 10 countries, November 2025 to January 2026 | Online survey. GoTo sells IT and communications software. | 25% of IT leaders say AI mistakes hurt customers; 79% of employees who review colleagues' AI work regularly get flawed output “around one-quarter of IT leaders say AI has made mistakes that affected customers” | edge.sitecorecloud.io ↗ |
Numbers you may have seen
These figures circulate widely. Here is what the original source says.
- Two thirds of employees use AI output without checking it (KPMG). 66% have done so at least once, including rarely. Doing it sometimes or more often is 42%, and 56% verify accuracy most of the time.
- 57% of workers have made mistakes because of AI (KPMG). The global report says 56%, counting anyone who did so even once. Sometimes or more often is 31%.
- AI is destroying critical thinking (Microsoft and Carnegie Mellon). The study measured 319 workers' own sense of effort and whether they thought critically. It did not test thinking skills or show a decline over time.
- 77% of employees review AI work as carefully as human work (Workday). The 77% covers only employees who use AI every day, at companies with more than $100 million in revenue, in a vendor survey.
- 66% of developers spend more time fixing AI code (Stack Overflow). 66% cite answers that are almost right; 45.2% say debugging AI code takes more time.
More from What Teams Trust
- F-2124–53%How much do workers trust the output of AI tools at work?
- F-2317–45%How often is AI output wrong on real work tasks?
- F-242–12%Which work tasks do people want AI to do on its own, and which do they want to keep?
- F-2530–44%How many workers use AI in ways that break company policy?
- F-2642–48%How often do employees put company data into public AI tools?
- F-2721–29%How many organizations have had a security incident or data breach involving AI?
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