Does the frontier smooth as models improve?

Unknown, and it matters a great deal. The experiment used GPT-4 in 2023, so tasks outside the frontier then may sit inside it now. Whether the boundary becomes smoother and more predictable, or simply moves while staying jagged, has not been studied. This research lists it as an open question rather than guessing.

What is the jagged frontier?

Q: What is the jagged frontier?

The irregular boundary between tasks an AI system performs well and tasks it performs badly. The point is that it is jagged rather than smooth: tasks that look equally difficult to a person sit on opposite sides of it, competence on one task tells you little about an adjacent one, and nothing in the output signals which side you are on. The term was introduced by Fabrizio Dell'Acqua and colleagues in 2023.

Q: What did the jagged frontier experiment find?

A pre-registered field experiment with 758 BCG consultants. On 18 realistic tasks inside the frontier, consultants using GPT-4 completed 12.2 per cent more tasks, 25.1 per cent faster, at more than 40 per cent higher quality. On one task deliberately chosen to sit outside it, consultants using AI were 19 percentage points less likely to produce a correct solution than consultants with no AI at all. Same people, same tool, opposite results.

Q: What are centaurs and cyborgs?

Two patterns among successful users identified in the same study. Centaurs divide the work, delegating whole sub-tasks to the machine or keeping them. Cyborgs integrate continuously, moving back and forth within a single task. Both terms have travelled widely, sometimes detached from the evidence that produced them, and neither has been established as superior.

Where the term comes from, the 758-consultant experiment that produced it, why the frontier finding matters more than the productivity figure, and what remains unknown about whether it smooths.

The jagged frontier is the boundary of what an AI system can do well, and the point is that it is jagged rather than smooth. Tasks that look equally difficult to a person sit on opposite sides of it. Competence on one task tells you very little about competence on an adjacent one, and nothing in the system's output tells you which side you are on.

Definition

The jagged technological frontier: the irregular boundary between tasks an AI system performs well and tasks it performs badly, where the two categories can be almost indistinguishable in apparent difficulty, and where the system gives no signal of having crossed from one to the other.

Where the term comes from

It was introduced in 2023 by Fabrizio Dell'Acqua and colleagues at Harvard Business School, Wharton and MIT, working with Boston Consulting Group, in a pre-registered field experiment with 758 consultants, roughly 7 per cent of BCG's individual-contributor consultants.

On 18 realistic consulting tasks inside the frontier, consultants using GPT-4 completed 12.2 per cent more tasks, 25.1 per cent faster, at more than 40 per cent higher quality. On one task deliberately selected to sit outside it, consultants using AI were 19 percentage points less likely to produce a correct solution than consultants with no AI at all.

Same people. Same tool. Same week. Opposite results, decided by which side of an invisible line the task happened to fall on.

Why it matters more than the productivity figure

The productivity numbers from that study are quoted constantly. The frontier finding is quoted far less, and it is the more useful half, because it explains why organisational results from AI are so inconsistent.

A smooth frontier would be manageable. You would learn roughly where competence ends and degrade your confidence gradually as tasks got harder. A jagged one is not manageable that way. You have to learn the shape empirically, task by task, in your own domain, and the map does not transfer to anyone else's.

This is also why fluency is such a poor guide. The system does not become hesitant when it crosses the line. It produces the same confident prose on both sides, which is why the consultants outside the frontier were not careless: they were reading output that gave them no signal.

Centaurs and cyborgs

The same study identified two patterns among successful users. Centaurs divide the work, delegating whole sub-tasks to the machine or keeping them. Cyborgs integrate continuously, moving back and forth within a single task. Both terms have travelled, sometimes detached from the evidence that produced them, and neither is established as superior.

What is uncertain

The experiment used GPT-4 in 2023, so the specific tasks outside the frontier then may sit comfortably inside it now. Whether the boundary smooths as models improve, or simply moves while staying jagged, is unstudied. It matters a great deal, and this research lists it as unknown rather than guessing. The finding also comes from a working paper rather than a peer-reviewed journal, which is why it is graded Tier B.

The SuperSkills view

The frontier is the reason "is AI good at this?" is the wrong question. The useful question is "in what circumstances is this system likely to be wrong for the kind of work I do?", and answering it requires a map you build yourself over months. That map is one of the few genuinely non-commoditised assets available, because it is made from your own work and cannot be bought.

It also has an uncomfortable corollary. Building a frontier map requires enough expertise to recognise a wrong answer in the first place, which makes it available to experienced practitioners and largely unavailable to anyone early in a career. That is synthetic seniority stated as a measurement problem.

Related SuperSkills research

The practical version is how do I know when AI is wrong. On the tendency that makes the frontier dangerous, automation bias. On what it means for pairing humans and machines, human-AI collaboration. On what leaders should take from it, what AI literacy means for leaders.

Key sources

Dell'Acqua, F., McFowland III, E., Mollick, E., Lifshitz-Assaf, H., Kellogg, K., Rajendran, S., Krayer, L., Candelon, F. and Lakhani, K. (2023). Navigating the Jagged Technological Frontier. Harvard Business School Technology and Operations Management Unit Working Paper 24-013.
Yu, F. et al. (2024). Heterogeneity and predictors of the effects of AI assistance on radiologists. Nature Medicine, 30(3).

About this definition

The jagged technological frontier is Dell'Acqua and colleagues' term and is not a SuperSkills coinage. It is defined here because the concept is referenced throughout this research and deserves an accurate account of its origin and its limits. Rahim Hirji is the author of SuperSkills (Kogan Page, 2026). On a 90-day review cycle, because model capability moves.

Cite this

Hirji, R. (2026). What is the jagged frontier? The SuperSkills Intelligence Company. Last reviewed 26 August 2026. thesuperskills.com/research/what-is-the-jagged-frontier