Does learning the right latent variables necessarily improve in-context learning?

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Mittal, Sarthak, Elmoznino, Eric, Gagnon, Leo, Bhardwaj, Sangnie, Marty, Tom, Sridhar, Dhanya, Lajoie, Guillaume
Natura: Preprint
Pubblicazione: 2024
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866908407450042368
author Mittal, Sarthak
Elmoznino, Eric
Gagnon, Leo
Bhardwaj, Sangnie
Marty, Tom
Sridhar, Dhanya
Lajoie, Guillaume
author_facet Mittal, Sarthak
Elmoznino, Eric
Gagnon, Leo
Bhardwaj, Sangnie
Marty, Tom
Sridhar, Dhanya
Lajoie, Guillaume
contents Large autoregressive models like Transformers can solve tasks through in-context learning (ICL) without learning new weights, suggesting avenues for efficiently solving new tasks. For many tasks, e.g., linear regression, the data factorizes: examples are independent given a task latent that generates the data, e.g., linear coefficients. While an optimal predictor leverages this factorization by inferring task latents, it is unclear if Transformers implicitly do so or if they instead exploit heuristics and statistical shortcuts enabled by attention layers. Both scenarios have inspired active ongoing work. In this paper, we systematically investigate the effect of explicitly inferring task latents. We minimally modify the Transformer architecture with a bottleneck designed to prevent shortcuts in favor of more structured solutions, and then compare performance against standard Transformers across various ICL tasks. Contrary to intuition and some recent works, we find little discernible difference between the two; biasing towards task-relevant latent variables does not lead to better out-of-distribution performance, in general. Curiously, we find that while the bottleneck effectively learns to extract latent task variables from context, downstream processing struggles to utilize them for robust prediction. Our study highlights the intrinsic limitations of Transformers in achieving structured ICL solutions that generalize, and shows that while inferring the right latents aids interpretability, it is not sufficient to alleviate this problem.
format Preprint
id arxiv_https___arxiv_org_abs_2405_19162
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Does learning the right latent variables necessarily improve in-context learning?
Mittal, Sarthak
Elmoznino, Eric
Gagnon, Leo
Bhardwaj, Sangnie
Marty, Tom
Sridhar, Dhanya
Lajoie, Guillaume
Machine Learning
Artificial Intelligence
Large autoregressive models like Transformers can solve tasks through in-context learning (ICL) without learning new weights, suggesting avenues for efficiently solving new tasks. For many tasks, e.g., linear regression, the data factorizes: examples are independent given a task latent that generates the data, e.g., linear coefficients. While an optimal predictor leverages this factorization by inferring task latents, it is unclear if Transformers implicitly do so or if they instead exploit heuristics and statistical shortcuts enabled by attention layers. Both scenarios have inspired active ongoing work. In this paper, we systematically investigate the effect of explicitly inferring task latents. We minimally modify the Transformer architecture with a bottleneck designed to prevent shortcuts in favor of more structured solutions, and then compare performance against standard Transformers across various ICL tasks. Contrary to intuition and some recent works, we find little discernible difference between the two; biasing towards task-relevant latent variables does not lead to better out-of-distribution performance, in general. Curiously, we find that while the bottleneck effectively learns to extract latent task variables from context, downstream processing struggles to utilize them for robust prediction. Our study highlights the intrinsic limitations of Transformers in achieving structured ICL solutions that generalize, and shows that while inferring the right latents aids interpretability, it is not sufficient to alleviate this problem.
title Does learning the right latent variables necessarily improve in-context learning?
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2405.19162