METR is a nonprofit that evaluates AI models' capabilities and risks, including studies of AI's effect on developer productivity.
Commenters cite its developer productivity studies, including the finding that developers were 19% slower with AI and the follow-up, and note its methods resemble government AI safety evaluations.
> What exactly does the evaluation entail?
I believe the US AISI has published less on their specific approach, but they’re largely expected to follow the general approach implemented by the UK AISI [1] and METR [2].
This is mostly focused on evaluating models on potentially dangerous capabilities. Some major areas of work include:
- Misuse risks: For example, determining whether models have (dual-use) expert-level knowledge in biology and chemistry, or the capacity to substantially facilitate large scale cyber attacks. A good example of this is the work by Soice et al on bioweapon uplift [5] or Meta's work on CYBERSECEVAL [6], respectively.
- Autonomy: Whether models are capable of agent-like behavior, like the kind that would be hard for humans to control. A big sub-area is Autonomous Replication and Adaptation (ARA), like the ability of the model to escape simulated environments and exfiltrate its own weights. A good example is METR's original set of evaluations on ARA capabilities [3].
- Safeguards: How vulnerable these models are to say, prompt injection attacks or jailbreaks, especially if they're also in principle capable of other dangerous capabilities (like the ones above). Good examples here are the UK AISI's work developing in-house attacks on frontier LLMs [4].
Labs like OAI, Anthropic and GDM already perform these internally as they're part of their respective responsible scaling policies, which determine which safety measures they should have implemented…
It's true that some people will just continually move the goalposts because they are invested in their beliefs. But that doesn't mean that the skepticism around certain claims aren't relevant.
Nobody serious is disputing that LLM's can generate working code. They dispute claims like "Agentic workflows will replace software developers in the short to medium term", or "Agentic workflows lead to 2-100x improvements in productivity across the board". This is what people are looking for in terms of evidence and there just isn't any.
Thus far, we do have evidence that AI (at least in OSS) produces a 19% decrease in productivity [0]. We also have evidence that it harms our cognitive abilities [1]. Anecdotally, I have found myself lazily reaching for LLM assistance when encountering a difficult problem instead of thinking deeply about the problem. Anecdotally I also struggle to be more productive using AI-centric agents workflows in areas of expertise.
We want evidence that "vibe engineering" is actually more productive across the entire lifespan of a software project. We want evidence that it produces better outcomes. Nobody has yet shown that. It's just people claiming that because they vibe coded some trivial project, all of software development can benefit from this approach. Recently a principle engineer at Google claimed that Claude Code wrote their team's entire year's worth of work in a single afternoon. They later walked that claim back, but most do not.
I'm more than…
Well, for example, consider this recent study that claimed developers using AI tools take 19% longer to finish tasks [1].
This was their methodology:
> we recruited 16 experienced developers from large open-source repositories (averaging 22k+ stars and 1M+ lines of code) that they’ve contributed to for multiple years. Developers provide lists of real issues (246 total) that would be valuable to the repository—bug fixes, features, and refactors that would normally be part of their regular work. Then, we randomly assign each issue to either allow or disallow use of AI while working on the issue.
Now consider the question of whether you expect this research to generalize. Do you expect that if you / your friends / your coworkers started using AI tools (or stopped using AI tools) that the difference in productivity would also be 19%? Of course not! They didn't look at enough people or contexts to get two sig figs of precision on that average, nor enough to expect the conclusion to generalize. Plus the AI tools are constantly changing, so even if the study was nailing the average productivity change it would be wrong a few months later. Plus the time period wasn't long enough for the people to build expertise, and "if I spend time getting good at this will it be worth it" is probably the real question we want answered. The study is so weak that I don't even feel compelled to trust the sign of their result to be predictive. And I would be saying the same thing if it reported…
"it's better at coding" is not useful information, sorry. i'd love to hear tangible ways it's actually better. does it still succumb to coding itself in circles, taking multiple dependencies to accomplish the same task, applying inconsistent, outdated, or non-idiomatic patterns for your codebase? has compliance with claude.md files and the like actually improved? what is the round trip time like on these improvements - do you have to have a long conversation to arrive at a simple result? does it still talk itself into loops where it keeps solving and unsolving the same problems? when you ask it to work through a complex refactor, does it still just randomly give up somewhere in the middle and decide there's nothing left to do? does it still sometimes attempt to run processes that aren't self-terminating to monitor their output and hang for upwards of ten minutes?
my experience with claude and its ilk are that they are insanely impressive in greenfield projects and collapse in legacy codebases quickly. they can be a force multiplier in the hands of someone who actually knows what they're doing, i think, but the evidence of that even is pretty shaky: https://metr.org/blog/2025-07-10-early-2025-ai-experienced-os-dev-study/
the pitch that "if i describe the task perfectly in absolute detail it will accomplish it correctly 80% of the time" doesn't appeal to me as a particularly compelling justification for the level of investment we're seeing. actually writing the code is the…
I see it brought up almost every week! It's a firm favorite of the "LLMs don't actually help write code" contingent, probably because there are very few other credible studies they can point to in support of their position.
Most people who cite it clearly didn't read as far as the table where METR themselves say:
> We do not provide evidence that:
> 1) AI systems do not currently speed up many or most software developers. Clarification: We do not claim that our developers or repositories represent a majority or plurality of software development work
> 2) AI systems do not speed up individuals or groups in domains other than software development. Clarification: We only study software development
> 3) AI systems in the near future will not speed up developers in our exact setting. Clarification: Progress is difficult to predict, and there has been substantial AI progress over the past five years [3]
> 4) There are not ways of using existing AI systems more effectively to achieve positive speedup in our exact setting. Clarification: Cursor does not sample many tokens from LLMs, it may not use optimal prompting/scaffolding, and domain/repository-specific training/finetuning/few-shot learning could yield positive speedup
https://metr.org/blog/2025-07-10-early-2025-ai-experienced-os-dev-study/
It's a solid question - and to some degree what https://programbench.com/ tries to measure.
Some of the issues (off the top of my head):
- Note - that my "product" was about 3,000 lines of code - so tiny. But https://metr.org/ should give you some insight into the complexity the models are capable of.
- you have to be able to imagine the product. If I have the time, and energy, to imagine what I want - the model will build it. Here is an example of a much better programmer than I and something he wanted built - https://www.boatbomber.com/blog/claude-fable-5
- These are the first drafts. On average - any complex system needs about 10 years and at least 1000 active and enthusiastic about reporting users to really get robust code. Writing if via LLM doesn't (at least so far in my experience) help that much in reducing bugs if you were previously following any semblance of TDD. Lots of bugs in the code - the products you listed above have literally tens of millions of years of user experiences and bug reports that got them to where they are today. No silver bullet yet - just faster, less effort - and it enables non-technical people to create (still buggy) products.