Author name cluster

Rohan Taori

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

7 papers

2 author rows

NeurIPS Conference 2023 Conference Paper

AlpacaFarm: A Simulation Framework for Methods that Learn from Human Feedback

Yann Dubois
Chen Xuechen Li
Rohan Taori
Tianyi Zhang
Ishaan Gulrajani
Jimmy Ba
Carlos Guestrin
Percy S. Liang

Large language models (LLMs) such as ChatGPT have seen widespread adoption due to their ability to follow user instructions well. Developing these LLMs involves a complex yet poorly understood workflow requiring training with human feedback. Replicating and understanding this instruction-following process faces three major challenges: the high cost of data collection, the lack of trustworthy evaluation, and the absence of reference method implementations. We address these bottlenecks with AlpacaFarm, a simulator that enables research and development for learning from feedback at a low cost. First, we design LLM based simulator for human feedback that is 45x cheaper than crowdworkers and displays high agreement with humans. Second, we identify an evaluation dataset representative of real-world instructions and propose an automatic evaluation procedure. Third, we contribute reference implementations for several methods (PPO, best-of-n, expert iteration, among others) that learn from pairwise feedback. Finally, as an end-to-end validation of AlpacaFarm, we train and evaluate eleven models on 10k pairs of human feedback and show that rankings of models trained in AlpacaFarm match rankings of models trained on human data. As a demonstration of the research possible in AlpacaFarm, we find that methods that use a reward model can substantially improve over supervised fine-tuning and that our reference PPO implementation leads to a +10% win-rate improvement against Davinci003.

PDF Details

ICML Conference 2023 Conference Paper

Data Feedback Loops: Model-driven Amplification of Dataset Biases

Rohan Taori
Tatsunori B. Hashimoto

Datasets scraped from the internet have been critical to large-scale machine learning. Yet, its success puts the utility of future internet-derived datasets at potential risk, as model outputs begin to replace human annotations as a source of supervision. In this work, we formalize a system where interactions with one model are recorded as history and scraped as training data in the future. We then analyze its stability over time by tracking changes to a test-time bias statistic (e. g. gender bias of model predictions). We find that the degree of bias amplification is closely linked to whether the model’s outputs behave like samples from the training distribution, a behavior which we characterize and define as uniform faithfulness. Experiments in three conditional prediction scenarios – image classification, visual role-labeling, and language generation – demonstrate that models that exhibit a sampling-like behavior are more faithful and thus more stable. Based on this insight, we propose an intervention to help mitigate and stabilize unstable feedback systems.

Details

ICLR Conference 2023 Conference Paper

Is a Caption Worth a Thousand Images? A Study on Representation Learning

Shibani Santurkar
Yann Dubois
Rohan Taori
Percy Liang
Tatsunori B. Hashimoto

The development of CLIP [Radford et al., 2021] has sparked a debate on whether adding language supervision can yield vision models with more transferable representations than traditional image-only methods. Our work studies this question through a carefully controlled comparison of two approaches, in terms of their ability to learn representations that generalize to downstream classification tasks. We find that when the pre-training data meets certain criteria---it is sufficiently large and contains descriptive captions with low variability----image-only methods do not match CLIP's performance even when they are trained with more image data. However, contrary to what one might expect, there are practical settings in which these criteria are not met, wherein added supervision through captions is actually detrimental. Motivated by our findings, we devise simple data and algorithmic interventions to improve the transfer performance of CLIP-style models.

Details

NeurIPS Conference 2023 Conference Paper

VisIT-Bench: A Dynamic Benchmark for Evaluating Instruction-Following Vision-and-Language Models

Yonatan Bitton
Hritik Bansal
Jack Hessel
Rulin Shao
Wanrong Zhu
Anas Awadalla
Josh Gardner
Rohan Taori

We introduce VisIT-Bench (Visual InsTruction Benchmark), a benchmark for evaluating instruction-following vision-language models for real-world use. Our starting point is curating 70 "instruction families" that we envision instruction tuned vision-language models should be able to address. Extending beyond evaluations like VQAv2 and COCO, tasks range from basic recognition to game playing and creative generation. Following curation, our dataset comprises 592 test queries, each with a human-authored instruction-conditioned caption. These descriptions surface instruction-specific factors, e. g. , for an instruction asking about the accessibility of a storefront for wheelchair users, the instruction-conditioned caption describes ramps/potential obstacles. These descriptions enable 1) collecting human-verified reference outputs for each instance; and 2) automatic evaluation of candidate multimodal generations using a text-only LLM, aligning with human judgment. We quantify quality gaps between models and references using both human and automatic evaluations; e. g. , the top-performing instruction-following model wins against the GPT-4 reference in just 27% of the comparison. VisIT-Bench is dynamic to participate, practitioners simply submit their model's response on the project website; Data, code and leaderboard is available at https: //visit-bench. github. io/.

PDF Details

ICML Conference 2021 Conference Paper

Accuracy on the Line: on the Strong Correlation Between Out-of-Distribution and In-Distribution Generalization

John Miller 0001
Rohan Taori
Aditi Raghunathan
Shiori Sagawa
Pang Wei Koh
Vaishaal Shankar
Percy Liang
Yair Carmon

For machine learning systems to be reliable, we must understand their performance in unseen, out- of-distribution environments. In this paper, we empirically show that out-of-distribution performance is strongly correlated with in-distribution performance for a wide range of models and distribution shifts. Specifically, we demonstrate strong correlations between in-distribution and out-of- distribution performance on variants of CIFAR- 10 & ImageNet, a synthetic pose estimation task derived from YCB objects, FMoW-WILDS satellite imagery classification, and wildlife classification in iWildCam-WILDS. The correlation holds across model architectures, hyperparameters, training set size, and training duration, and is more precise than what is expected from existing domain adaptation theory. To complete the picture, we also investigate cases where the correlation is weaker, for instance some synthetic distribution shifts from CIFAR-10-C and the tissue classification dataset Camelyon17-WILDS. Finally, we provide a candidate theory based on a Gaussian data model that shows how changes in the data covariance arising from distribution shift can affect the observed correlations.

Details

NeurIPS Conference 2021 Conference Paper

Are We Learning Yet? A Meta Review of Evaluation Failures Across Machine Learning

Thomas Liao
Rohan Taori
Deborah Raji
Ludwig Schmidt

Many subfields of machine learning share a common stumbling block: evaluation. Advances in machine learning often evaporate under closer scrutiny or turn out to be less widely applicable than originally hoped. We conduct a meta-review of 107 survey papers from natural language processing, recommender systems, computer vision, reinforcement learning, computational biology, graph learning, and more, organizing the wide range of surprisingly consistent critique into a concrete taxonomy of observed failure modes. Inspired by measurement and evaluation theory, we divide failure modes into two categories: internal and external validity. Internal validity issues pertain to evaluation on a learning problem in isolation, such as improper comparisons to baselines or overfitting from test set re-use. External validity relies on relationships between different learning problems, for instance, whether progress on a learning problem translates to progress on seemingly related tasks.

PDF Details

NeurIPS Conference 2020 Conference Paper

Measuring Robustness to Natural Distribution Shifts in Image Classification

Rohan Taori
Achal Dave
Vaishaal Shankar
Nicholas Carlini
Benjamin Recht
Ludwig Schmidt

We study how robust current ImageNet models are to distribution shifts arising from natural variations in datasets. Most research on robustness focuses on synthetic image perturbations (noise, simulated weather artifacts, adversarial examples, etc. ), which leaves open how robustness on synthetic distribution shift relates to distribution shift arising in real data. Informed by an evaluation of 204 ImageNet models in 213 different test conditions, we find that there is often little to no transfer of robustness from current synthetic to natural distribution shift. Moreover, most current techniques provide no robustness to the natural distribution shifts in our testbed. The main exception is training on larger and more diverse datasets, which in multiple cases increases robustness, but is still far from closing the performance gaps. Our results indicate that distribution shifts arising in real data are currently an open research problem.

PDF Details