Vishakh Padmakumar

@vishakhpk.bsky.social

PhD Student @nyudatascience.bsky.social, working with He He on NLP and Human-AI Collaboration. Also hanging out @ai2.bsky.social Website - https://vishakhpk.github.io/

Last year I worked at @adobe.com and @ai2.bsky.social, exploring how we can help users read, organize and understand long documents. This piece covers what we learned on modelling user intent and combining LLMs with principled tools when building complex pipelines for it!

NYU Center for Data Science@nyudatascience.bsky.social · 9mo ago

CDS PhD alum Vishakh Padmakumar (@vishakhpk.bsky.social), now at Stanford, tackled the hard part of summarization — deciding what matters. At Adobe, he built diversity-aware summarizers; at AI2, intent-based tools for literature review tables. nyudatascience.medium.com/supercharged...

When using LLM-as-a-judge, practitioners often use greedy decoding to get the most likely judgment. But we found that deriving a score from the judgment distribution (like taking the mean) works better! ❌LLM-as-a-judge with greedy decoding 😎Using the distribution of the judge’s labels

Victor Wang@victorwang37.bsky.social · last yr.

LLM judges have become ubiquitous, but valuable signal is often ignored at inference. We analyze design decisions for leveraging judgment distributions from LLM-as-a-judge: 🧵 (w/ Michael J.Q. Zhang, @eunsol.bsky.social)

Ever looked at LLM skill emergence and thought 70B parameters was a magic number? Our new paper shows sudden breakthroughs are samples from bimodal performance distributions across seeds. Observed accuracy jumps abruptly while the underlying accuracy DISTRIBUTION changes slowly!

Distributional Scaling Laws for Emergent Capabilities
Rosie Zhao, Tian Qin, David Alvarez-Melis, Sham Kakade, Naomi Saphra
In this paper, we explore the nature of sudden breakthroughs in language model performance at scale, which stands in contrast to smooth improvements governed by scaling laws. While advocates of "emergence" view abrupt performance gains as capabilities unlocking at specific scales, others have suggested that they are produced by thresholding effects and alleviated by continuous metrics. We propose that breakthroughs are instead driven by continuous changes in the probability distribution of training outcomes, particularly when performance is bimodally distributed across random seeds. In synthetic length generalization tasks, we show that different random seeds can produce either highly linear or emergent scaling trends. We reveal that sharp breakthroughs in metrics are produced by underlying continuous changes in their distribution across seeds. Furthermore, we provide a case study of inverse scaling and show that even as the probability of a successful run declines, the average performance of a successful run continues to increase monotonically. We validate our distributional scaling framework on realistic settings by measuring MMLU performance in LLM populations. These insights emphasize the role of random variation in the effect of scale on LLM capabilities.

🚨New Paper! So o3-mini and R1 seem to excel on math & coding. But how good are they on other domains where verifiable rewards are not easily available, such as theory of mind (ToM)? Do they show similar behavioral patterns? 🤔 What if I told you it's...interesting, like the below?🧵

Bild

🤔 Ever wondered how prevalent some type of web content is during LM pre-training? In our new paper, we propose WebOrganizer which *constructs domains* based on the topic and format of CommonCrawl web pages 🌐 Key takeaway: domains help us curate better pre-training data! 🧵/N

Bild

CDS' He He, @vishakhpk.bsky.social, & former CDS postdoc Abulhair Saparov, et al, find major AI limits in “Transformers Struggle to Learn to Search.” AI models excel at single-step reasoning but fail in systematic exploration as tasks grow in complexity. nyudatascience.medium.com/even-simple-...

Even Simple Search Tasks Reveal Fundamental Limits in AI Language Models

Research by CDS’ He He, Vishakh Padmakumar, and others shows that LLMs’ reasoning relies on heuristics, not systematic exploration.

nyudatascience.medium.com

People often claim they know when ChatGPT wrote something, but are they as accurate as they think? Turns out that while general population is unreliable, those who frequently use ChatGPT for writing tasks can spot even "humanized" AI-generated text with near-perfect accuracy 🎯

Bild

🔥While LLM reasoning is on people's minds... Here's a shameless plug for our work comparing o1 to previous LLMs (extending "Embers of Autoregression"): arxiv.org/abs/2410.01792 - o1 shows big improvements over GPT-4 - But qualitatively it is still sensitive to probability 1/4

A plot showing LLM performance on various algorithmic tasks. For all LLMs evaluated, including o1-preview, performance is highly influenced by the probability of the output to be produced, with lower performance on cases with low-probability outputs. The tasks being evaluated on are shift ciphers, Pig Latin, article swapping, and reversal.