August 27, 2026, (Inside AI) — A new randomized experiment at Bocconi University found that giving students access to ChatGPT improved the quality of their work, while a separate critical-thinking exercise made their ideas more original. The two interventions worked in complementary ways, with students who received both showing the widest range of benefits.
The study, conducted with OpenAI Economic Research, involved more than 1,000 first-year undergraduates working on a real business case: developing marketing recommendations for the university's merchandise store. Students were randomly assigned by class period to one of four groups: access to GPT‑4o, training in causal reasoning, both, or neither.
Human graders scored submissions on a five-point rubric that measured how well recommendations addressed two standard marketing goals: increasing awareness and use of the store. Students with ChatGPT access scored almost a full point higher. Their answers included more ideas, followed clearer logic, and were more similar to recommendations written by experts.
But the critical-thinking exercise produced a more unexpected result. Students who completed it explained more clearly why their ideas might work and when they might fail, yet did not score higher on the rubric. Automated text analysis revealed that these students produced a wider range of ideas that were more distinct when compared to their peers.
This gap points to a broader challenge for schools. If AI can help students produce polished, expert-like work, then looking only at the final answer tells us less about what a student actually understands. The study suggests that assignments and evaluations may need to change to reward originality, reasoning, and consideration of multiple approaches.
The Hidden Metric Rubrics Miss
The experiment's randomized design allowed researchers to separate the effects of ChatGPT access and causal-reasoning training from the effect of combining them. Students who received both showed idea variety matching those who completed only the exercise, while their rubric scores and number of ideas were similar to those with ChatGPT access alone.
Their work also showed stronger logical coherence and more evidence of looking for explanations and questioning assumptions. Overall, this group showed gains across the widest range of measures.
Importantly, students weren't simply handing over their assignments to ChatGPT. They still had to decide what to ask, evaluate the responses, and choose what went into their final submission. This active engagement may explain why AI access improved quality without reducing the need for human judgment.
The training students received was unrelated to AI. It taught causal reasoning concepts through an exercise that involved a game, examples, questions, and feedback. Causal reasoning is a specific form of critical thinking related to linking cause and effect and explaining why a given solution may or may not work.
AI and Critical Thinking Are Not Rivals
It can be tempting to frame the education debate as a choice of whether students should learn to think for themselves or learn to use AI. This experiment highlights that both are valuable in different ways. AI access helped students produce answers that were more polished, idea-rich, and more logically coherent. Critical-thinking training encouraged them to develop a wider range of original ideas, question assumptions, and explain why their ideas should work.
Together, they are complementary. The takeaway is clear: AI helped students make their answers better. Critical-thinking training helped make their ideas broader. The two play complementary roles in preparing students for the future.
Many educators are already grappling with the implication that assignments and evaluations may need to change. This follows a multi-decade pattern of technology and education evolving together in service of supporting the skills students need in modern society. The study is a particularly useful contribution to a rapidly growing body of research on the impact of AI on students and how to best structure and support their learning.
