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Ask HN: How are people doing AI evals these days?

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21–30 of 52 posts

Re: Ask HN: How are people doing AI evals these days?

#21
We feed a handful of preset questions through the new AI, we collect the results, we ask another AI to score the answers based on example ‘hood’ answers we’ve written, then we have a guy sit down and use the fallout as a starting point to rank the performance of that AI, compared to all the previous ones.

Seems like it works pretty well. Our prompts and params get tweaked towards better and better results, and we get a sense of what’s worth paying more for.

Re: Ask HN: How are people doing AI evals these days?

#22

It’s called testing. And from the reports and comments, there doesn’t seem to be much of it happening. The reason is: it’s quite expensive to do well. I find that for every hypothesis I might have to run a thousand prompts to collect enough data for a conclusion. For instance, to discover how reliably different models can extract noun phrases from a text: hours of grinding. Even so that was for a small text. I haven’…

Seems like you are testing llms genric abilities rather than your actual agent logic.

Llms are like vendor code you don't need to test them yourself people already created benchmarks for that.

Re: Ask HN: How are people doing AI evals these days?

#24
I highly rate Braintrust.

It wouldn’t be too difficult to build something like that for your own usage, but I found it pretty easy to get datasets set up.

Essentially a game changer in understanding if your prompts are working. Especially if you’re doing something which requires high levels of consistency.

In our case we would use LLM for classification which fits in perfectly with evals.

Re: Ask HN: How are people doing AI evals these days?

#26
I'm also curious about this.

In some cases I've seen teams rely on a mix of automated metrics and human review, especially for production systems where reliability matters a lot.

But evaluation pipelines for AI still seem much less standardized compared to traditional software monitoring.

Re: Ask HN: How are people doing AI evals these days?

#27
It's kind of bespoke for me tbh.

For a co-pilot inside an app that could answer product questions, I looked at ~2000 or so support emails. I asked one LLM to dig out "How would you formulate the users question into a chatbot-like question from this email thread" and "What is the actual answer that should be in the response from this email thread", then just asked our bot that question, and have another LLM rate the answer like SUPERIOR | ACCEPTABLE | UNKNOWN etc. These labels proved out to be a good "finger in the wind"-indicator for altering the chunks, prompt changes or model updates.

For an invoice procesing app processing about 14M invoices/year, it was mostly doing fuzzy accuracy metrics against a pretty ok annotated dataset and iterating the prompt based on diffs for a long time. Once you had that dataset you could alter things and see what broke.

Currently, I work on an app with a pretty sophisicated prompt chain flow. Depending on bugs etc we kind of do tests against _behaviour_, like intent recognition or the correct sql filters. As long as the baseline is working with the correct behaviour, whatever model is powering it is not so important. For the final output, it's humans. But we know immediately if some model or prompt change broke some particular intent.

Re: Ask HN: How are people doing AI evals these days?

#28
I was thinking about something similar the other day. I have seen a repeating pattern of people complaining that a new model comes out, it's amazing for a few weeks, then they nerf it.

Most of these claims are subjective. I was thinking if we had a standardized chain of though representation, and if we could capture each models chain of thought into this standardized format, we could compare these for the same tasks we run.

Re: Ask HN: How are people doing AI evals these days?

#29
post #22

It’s called testing. And from the reports and comments, there doesn’t seem to be much of it happening. The reason is: it’s quite expensive to do well. I find that for every hypothesis I might have to run a thousand prompts to collect enough data for a conclusion. For instance, to discover how reliably different models can extract noun phrases from a text: hours of grinding. Even so that was for a small text. I haven’…

Seems like you are testing llms genric abilities rather than your actual agent logic. Llms are like vendor code you don't need to test them yourself people already created benchmarks for that.

No they haven’t. The benchmarks suck, because they are cheap knockoffs instead of comprehensive experiments.

LLMs are poorly tested by vendors. They literally can’t afford to test them, so they force us to do it.

Re: Ask HN: How are people doing AI evals these days?

#30
post #3

Very, very heterogenous and fast moving space. Depending on how they're made up, different teams do vastly different things. No evals at all, integration tests with no tooling, some use mixed observability tools like LangFuse in their CI/CD. Some other tools like arize phoenix, deepeval, braintrust, promptfoo, pydanticai throughout their development. It's definitely an afterthought for most teams although we are star…

What I've noticed is that it's hard to measure outputs that aren't binary right or wrong, and that's where most human intervention is needed. The biggest examples of this are chatbots and coding agents – basically any output where you can say "hmm well that's a good response, but there is a better response" and that's what still _feels_ like an unsolved problem, benchmarking those kinds of responses.

On top of that, there are combinations of models+prompts that give different results. For example a prompt could yield a great response from Claude, but the same prompt could yield a mediocre response from Gemini. Not just that but different models have different capabilities (example of this is that composite function calling doesn't work the same way for all models).

I'm asking because I'm generally curious on how teams are solving this today – and it _seems_ like there is no gold standard for evals yet although it's gaining interest.

How I do evals today is by testing an output across different dimensions (and it can vary based on use-case): relevance, instruction following, clarity, hallucination rate, etc. which sucks a lot of time (and can never be fully accurate because how do you fully measure something like "clarity"?), and I feel like there's a better way out there.

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