That means they can require a lot of back and forth, which might take longer than if you just wrote the code yourself. But participants in the study offered several more human hypotheses, too. “LLMs ...

The study, conducted by the nonprofit research group METR, found that the software engineers took 19 per cent longer to complete tasks when using Cursor, a widely used AI-powered coding assistant.

Based on the study, developers shouldn’t assume that AI coding tools — specifically what’s come to be known as “vibe coders” — will immediately speed up their workflows.

Participants were randomly placed into one of four groups: working solo or in teams, and with or without AI access. The study measured solution quality, task completion time, and emotional response.

The results were very unexpected. What the study found — METR measured the speed of 16 developers working on complex software projects, both with and without AI assistance.