Large Language Model
Nvidia's G-Assist AI now works with Twitch, Spotify, and Gemini
Nvidia is mighty proud of G-Assist, its new "AI" companion that runs on top of an active game and helps you out with tips or hardware adjustments. Now, it looks like the company is preparing to expand its capabilities. A new plugin-making system and several examples are already letting the tool's tendrils expand to other services. While standard developers can already use the G-Assist API, Nvidia is hoping that more regular users will get in on the action, and has made a Plugin Builder to achieve this. Using ChatGPT's generative code capabilities, it allows even a complete novice to "vibe code" and connect it with anything that also has an open API or a similar setup.
ChatGPT maker OpenAI wants to buy Chrome from Google
Google is having a bit of a moment. It's not quite an Enron- or FTX-style "abandon ship" situation, but between two separate US antitrust rulings on its core search and advertising businesses, it's a five-alarm fire. One of the possible outcomes is Google selling off the Chrome browserโฆ and it looks like one possible buyer is OpenAI, maker of ChatGPT. OpenAI's head of product for ChatGPT is named Nick Turley, and he testified at the remedy phase of the Department of Justice's successful monopoly suit against Google. When asked if OpenAI would be interested in buying the Chrome browser from Google, Turley didn't mince words.
ChatGPT-maker wants to buy Google Chrome
The current trial is looking at remedies to curtail Google's dominance in online search, as the recent explosion in generative AI services such as ChatGPT has expanded the market. Newer AI models search the internet to improve results and reduce hallucination, which has been a problem from developers since chatbots started to become popular. Last year, OpenAI offered to do a deal with Google which would have integrated Google search results into ChatGPT, according to Mr Turley's testimony. But he says their offer was rejected. "We have no partnership with Google today," Mr Turley said, according to Reuters. OpenAI does however have a partnership with Microsoft, which makes the Bing search engine and Edge browser.
3 Things Caiwei Chen is into right now
I recently saw Doomers, a new play by Matthew Gasda about the aborted 2023 coup at OpenAI, here represented by a fictional company called MindMesh. The action is set almost entirely in a meeting room; the first act follows executives immediately after the firing of company CEO Seth (a stand-in for Sam Altman), and the second re-creates the board negotiations that determined his fate. It's a solid attempt to capture the zeitgeist of Silicon Valley's AI frenzy and the world's moral panic over artificial intelligence, but the rapid-fire, high-stakes exchanges mean it sometimes seems to get lost in its own verbosity. The vastness of Chinese cuisine defies easy categorization, and even in a city with no shortage of options, I often find myself cooking--not just to recapture something closer to home, but to create a home unlike one that ever existed. Recently, I've been experimenting with a Chinese take on the charcuterie board--pairing toasted steamed buns, called mantou, with furu, a fermented tofu spread that is sharp, pungent, and full of umami. I started sewing three years ago, but only in the past year have I begun making clothes from scratch.
Training Large Language Models to Reason via EM Policy Gradient
Recently, foundation models such as OpenAI's O1 and O3, along with DeepSeek's R1, have demonstrated strong reasoning capacities and problem-solving skills acquired through large-scale reinforcement learning (RL), with wide applications in mathematics, coding, science, intelligent agents, and virtual assistants. In this work, we introduce an off-policy reinforcement learning algorithm, EM Policy Gradient, aimed at enhancing LLM reasoning by optimizing expected return over reasoning trajectories. We frame the reasoning task as an Expectation-Maximization (EM) optimization problem, alternating between sampling diverse rationale trajectories and performing reward-guided fine-tuning. Unlike PPO and GRPO, which rely on complex importance weights and heuristic clipping, our method provides a simpler, more principled off-policy policy gradient approach, eliminating these complexities while maintaining strong performance. We evaluate the effectiveness of EM Policy Gradient on the GSM8K and MATH (HARD) datasets, where it achieves performance comparable to or slightly surpassing the state-of-the-art GRPO, while offering additional advantages in scalability, simplicity, and reasoning conciseness. Moreover, models fine-tuned with our method exhibit cognitive behaviors, such as sub-problem decomposition, self-verification, and backtracking, highlighting its potential to enhance both the interpretability and robustness of LLM reasoning.
(Im)possibility of Automated Hallucination Detection in Large Language Models
Karbasi, Amin, Montasser, Omar, Sous, John, Velegkas, Grigoris
Is automated hallucination detection possible? In this work, we introduce a theoretical framework to analyze the feasibility of automatically detecting hallucinations produced by large language models (LLMs). Inspired by the classical Gold-Angluin framework for language identification and its recent adaptation to language generation by Kleinberg and Mullainathan, we investigate whether an algorithm, trained on examples drawn from an unknown target language $K$ (selected from a countable collection) and given access to an LLM, can reliably determine whether the LLM's outputs are correct or constitute hallucinations. First, we establish an equivalence between hallucination detection and the classical task of language identification. We prove that any hallucination detection method can be converted into a language identification method, and conversely, algorithms solving language identification can be adapted for hallucination detection. Given the inherent difficulty of language identification, this implies that hallucination detection is fundamentally impossible for most language collections if the detector is trained using only correct examples from the target language. Second, we show that the use of expert-labeled feedback, i.e., training the detector with both positive examples (correct statements) and negative examples (explicitly labeled incorrect statements), dramatically changes this conclusion. Under this enriched training regime, automated hallucination detection becomes possible for all countable language collections. These results highlight the essential role of expert-labeled examples in training hallucination detectors and provide theoretical support for feedback-based methods, such as reinforcement learning with human feedback (RLHF), which have proven critical for reliable LLM deployment.
LLMs are Greedy Agents: Effects of RL Fine-tuning on Decision-Making Abilities
Schmied, Thomas, Bornschein, Jรถrg, Grau-Moya, Jordi, Wulfmeier, Markus, Pascanu, Razvan
The success of Large Language Models (LLMs) has sparked interest in various agentic applications. A key hypothesis is that LLMs, leveraging common sense and Chain-of-Thought (CoT) reasoning, can effectively explore and efficiently solve complex domains. However, LLM agents have been found to suffer from sub-optimal exploration and the knowing-doing gap, the inability to effectively act on knowledge present in the model. In this work, we systematically study why LLMs perform sub-optimally in decision-making scenarios. In particular, we closely examine three prevalent failure modes: greediness, frequency bias, and the knowing-doing gap. We propose mitigation of these shortcomings by fine-tuning via Reinforcement Learning (RL) on self-generated CoT rationales. Our experiments across multi-armed bandits, contextual bandits, and Tic-tac-toe, demonstrate that RL fine-tuning enhances the decision-making abilities of LLMs by increasing exploration and narrowing the knowing-doing gap. Finally, we study both classic exploration mechanisms, such as $ฮต$-greedy, and LLM-specific approaches, such as self-correction and self-consistency, to enable more effective fine-tuning of LLMs for decision-making.
Guiding VLM Agents with Process Rewards at Inference Time for GUI Navigation
Hu, Zhiyuan, Xiong, Shiyun, Zhang, Yifan, Ng, See-Kiong, Luu, Anh Tuan, An, Bo, Yan, Shuicheng, Hooi, Bryan
Recent advancements in visual language models (VLMs) have notably enhanced their capabilities in handling complex Graphical User Interface (GUI) interaction tasks. Despite these improvements, current frameworks often struggle to generate correct actions in challenging GUI environments. State-of-the-art commercial VLMs are black-boxes, and fine-tuning open-source VLMs for GUI tasks requires significant resources. Additionally, existing trajectory-level evaluation and refinement techniques frequently fall short due to delayed feedback and local optimization issues. To address these challenges, we propose an approach that guides VLM agents with process supervision by a reward model during GUI navigation and control at inference time. This guidance allows the VLM agent to optimize actions at each inference step, thereby improving performance in both static and dynamic environments. In particular, our method demonstrates significant performance gains in three GUI navigation tasks, achieving a 3.4% improvement in single step action accuracy for static environments, along with a around 33% increase in task success rate in one dynamic environment. With further integration of trajectory reflection and retry mechanisms, we also demonstrate even greater enhancement in task success.
Describe Anything: Detailed Localized Image and Video Captioning
Lian, Long, Ding, Yifan, Ge, Yunhao, Liu, Sifei, Mao, Hanzi, Li, Boyi, Pavone, Marco, Liu, Ming-Yu, Darrell, Trevor, Yala, Adam, Cui, Yin
Generating detailed and accurate descriptions for specific regions in images and videos remains a fundamental challenge for vision-language models. We introduce the Describe Anything Model (DAM), a model designed for detailed localized captioning (DLC). DAM preserves both local details and global context through two key innovations: a focal prompt, which ensures high-resolution encoding of targeted regions, and a localized vision backbone, which integrates precise localization with its broader context. To tackle the scarcity of high-quality DLC data, we propose a Semi-supervised learning (SSL)-based Data Pipeline (DLC-SDP). DLC-SDP starts with existing segmentation datasets and expands to unlabeled web images using SSL. We introduce DLC-Bench, a benchmark designed to evaluate DLC without relying on reference captions. DAM sets new state-of-the-art on 7 benchmarks spanning keyword-level, phrase-level, and detailed multi-sentence localized image and video captioning.
Vision language models are unreliable at trivial spatial cognition
Khemlani, Sangeet, Tran, Tyler, Gyory, Nathaniel, Harrison, Anthony M., Lawson, Wallace E., Thielstrom, Ravenna, Thompson, Hunter, Singh, Taaren, Trafton, J. Gregory
Vision language models (VLMs) are designed to extract relevant visuospatial information from images. Some research suggests that VLMs can exhibit humanlike scene understanding, while other investigations reveal difficulties in their ability to process relational information. To achieve widespread applicability, VLMs must perform reliably, yielding comparable competence across a wide variety of related tasks. We sought to test how reliable these architectures are at engaging in trivial spatial cognition, e.g., recognizing whether one object is left of another in an uncluttered scene. We developed a benchmark dataset -- TableTest -- whose images depict 3D scenes of objects arranged on a table, and used it to evaluate state-of-the-art VLMs. Results show that performance could be degraded by minor variations of prompts that use logically equivalent descriptions. These analyses suggest limitations in how VLMs may reason about spatial relations in real-world applications. They also reveal novel opportunities for bolstering image caption corpora for more efficient training and testing.