Skip to content
Back to the collection

Inference-Time Intervention: Eliciting Truthful Answers from a Language Model

Kenneth Li, Oam Patel, Fernanda Viégas, Hanspeter Pfister, Martin Wattenberg

2023 · arXiv

Read the paper
HN score
0
Mentions
4
Readers
4
Months
4
What’s in a score?

From the abstract

We introduce Inference-Time Intervention (ITI), a technique designed to enhance the "truthfulness" of large language models (LLMs). ITI operates by shifting model activations during inference, following a set of directions across a limited number of attention heads. This intervention significantly improves the performance of LLaMA models on the TruthfulQA benchmark. On an instruction-finetuned LLaMA called Alpaca, ITI improves its truthfulness from 32.5% to 65.1%. We identify a tradeoff between truthfulness and helpfulness and demonstrate how to balance it by tuning the intervention strength. ITI is minimally invasive and computationally inexpensive. Moreover, the technique is data efficient: while approaches like RLHF require extensive annotations, ITI locates truthful directions using only few hundred examples. Our findings suggest that LLMs may have an internal representation of the likelihood of something being true, even as they produce falsehoods on the surface.

Metadata: arXiv. Abstracts retain their original authors’ rights.

In the conversation

Original HN comments, with labels from simple text rules. A label describes the whole comment and may miss context or irony. Read the discussion to make up your own mind. About the labels

4 selected excerpts · 4 total mentions

skhameneh
Neutral mention · rule
I was talking to an old colleague/friend about distillation, trying to understand how to steer distillation with regards to removing irrelevant regions of a larger model when training a smaller model. He shared this paper with me, calling the works seminal, it appears to be highly relevant: Inference-Time Intervention: Eliciting Truthful Answers from a Language Model https://arxiv.org/pdf/2306.03341
agucova
Neutral mention · rule
> If training data contains multiple conflicting perspectives on a topic, the LLM has a limited ability to recognize that a disagreement is present and what types of entities are more likely to adopt which side. That is what those studies are reflecting. Again, we have empirical evidence to suggest otherwise. It's not that there's an oracle, but that the LLM does internally differentiate between facts it has stored as simple truth vs. misconceptions vs. fiction. This becomes obvious by interacting with popular LLMs; they can produce decent essays explaining different perspectives on various issues, and it makes total sense that they can because if you need to predict…
Read the full comment
tokens on the internet, you better be able to take on different perspectives. Hell, we can even intervene these internal mechanisms to elicit true answers from a model, in contexts where you would otherwise expect the LLM to output a misconception. To quote a recent paper, "Our findings suggest that LLMs may have an internal representation of the likelihood of something being true, even as they produce falsehoods on the surface" [1], and this matches the rest of the interpretability literature on the topic. [1]: https://arxiv.org/pdf/2306.03341
astrange
Neutral mention · rule
> demonstrate that the LLM will deny that they know fact X (or be flaky about it, randomly denying and divulging the fact) No, the sampling algorithm you used to query the LLM does that. Not the model itself. e.g. https://arxiv.org/pdf/2306.03341.pdf > B. They know they know fact X, but avoid acknowledging for ... reasons? That reason being that the sampling algorithm didn't successfully sample the answer.
cubefox
Neutral mention · rule
Yeah. See e.g. https://arxiv.org/abs/2306.03341 > Our findings suggest that LLMs may have an internal representation of the likelihood of something being true, even as they produce falsehoods on the surface. The problem here is that there is currently no way to extract information from this hypothetical world model. Language models do not always say what they "believe", they might instead say what is politically correct, what sounds good etc. Researchers try to optimize (fine-tune) language models to be helpful, honest, and harmless, but honesty ("truthfulness") can't be easily optimized for.

Keep following the thread.

More in Language models

More from the same topics.