Statistics & Machine Learning Reading Group

Carnegie Mellon University

About

Welcome! We are a group of faculty, postdocs and PhD students located at Carnegie Mellon University, broadly interested in research at the intersection of Statistics and Machine Learning.

Schedule for Fall 2026

Tuesdays, 12-1pm · GHC 4405
1 Sep
Statistical Viewpoint for Shapley Value Estimation
Shapley values and related probabilistic values provide a flexible model-agnostic framework for attributing the behavior of a black-box system to data points, features, or other components, with a wide range of applications from model explanation and data valuation to credit assignment and compensation. Their practical use, however, is limited by a fundamental computational challenge: exact evaluation requires considering exponentially many coalitions, while even a single coalition evaluation may involve expensive model training or inference. In this talk, I will present a unified first-order perspective on Monte Carlo estimation of probabilistic values. Although existing estimators are motivated by seemingly different strategies, many share a common error structure that reveals how coalition sampling and surrogate modeling jointly determine statistical efficiency. This perspective leads to an Efficiency-Aware Surrogate-adjusted Estimator (EASE) that directly minimizes an explicit first-order approximation to the mean squared error. We demonstrate that EASE consistently improves estimation accuracy compared to existing estimators under the same utility-evaluation budget.
8 Sep
Do Language Models Need Sleep?
Transformer-based large language models are increasingly used for long-horizon tasks. Solving such tasks requires persistent memory rather than simply relying on an expensive and ever-growing context window. In this talk, I'll present our recent work on a sleep-like consolidation mechanism in which a model periodically converts recent context into persistent fast weights before clearing its key-value cache. During "sleep", the model performs N offline recurrent passes over the accumulated context and updates the fast weights in its state-space model blocks. We show that increasing sleep duration N for our models improves performance, with the largest gains on examples that require deeper reasoning.
15 Sep
Up next
Tensor Programs V: Tuning Large Neural Networks via Zero-Shot Hyperparameter Transfer
Hyperparameter (HP) tuning in deep learning is an expensive process, prohibitively so for neural networks (NNs) with billions of parameters. We show that, in the recently discovered Maximal Update Parametrization (muP), many optimal HPs remain stable even as model size changes. This leads to a new HP tuning paradigm we call muTransfer: parametrize the target model in muP, tune the HP indirectly on a smaller model, and zero-shot transfer them to the full-sized model, i.e., without directly tuning the latter at all. We verify muTransfer on Transformer and ResNet. For example, 1) by transferring pretraining HPs from a model of 13M parameters, we outperform published numbers of BERT-large (350M parameters), with a total tuning cost equivalent to pretraining BERT-large once; 2) by transferring from 40M parameters, we outperform published numbers of the 6.7B GPT-3 model, with tuning cost only 7% of total pretraining cost. A Pytorch implementation of our technique can be found at this http URL and installable via `pip install mup`.
22 Sep
Speaker to be confirmed
Room: GHC 6121
29 Sep
Minimax Estimation of Velocity Fields from Snapshots and Trajectories
6 Oct
Online Prediction Intervals with Prior Knowledge: A Conformal Approach for Time Series
13 Oct
Fall break
20 Oct
Title to be announced
27 Oct
Wasserstein Least Squares
We perform a mathematical and statistical analysis of the Wasserstein least squares problem, a regression method for vector-valued covariates and distribution-valued responses. Our proposal contrasts with other distributional regression methods by having a direct interpretation in terms of random variables, as a nonparametric analogue of the classic random-effects model. On the mathematical side, we use a strategy of Lavenant (2024) to show that Wasserstein least squares is the canonical extension of Euclidean least squares to the space of probability distributions from the perspective of convex analysis; this viewpoint gives rise to multimarginal and dual formulations of the Wasserstein least squares problem, extending a similar theory for Wasserstein barycenters. We perform a statistical analysis of the Wasserstein least squares problem under the template deformation model, showing, surprisingly, that estimation is possible at the n^{-1/2} rate. As a special case, we obtain improved rates of estimation for Wasserstein barycenters, which are an exponential improvement over those established by Ahidar-Coutrix, Le Gouic and Paris (2020). Finally, we propose a heuristic particle method for Wasserstein least squares and use it to conduct a novel analysis of large-scale demographic data from the RAND Health and Retirement Study.
3 Nov
Speaker to be confirmed
10 Nov
Title to be announced
17 Nov
How well do time-series foundation models predict infectious disease?
I'll give a quick overview on time-series foundation models: the premise, different architectures & models, how well they seem to do in practice, etc. Then present some results of our analysis in the context of infectious disease forecasting.
24 Nov
Speaker to be confirmed
1 Dec
Speaker to be confirmed

Browse past talks

Joining

Anyone at CMU is welcome to attend. To join the mailing list, to volunteer to present, or to be added to the people page, email one of the organizers.

Organizers

Eric Chen and Tomas Gonzalez are organizing the group for the 2026–2027 academic year.