How Good is a Single Basin?

Published: 02 Nov 2023, Last Modified: 18 Dec 2023UniReps PosterEveryoneRevisionsBibTeX
Supplementary Material: pdf
Keywords: Ensembles, Loss landscapes, Linear mode connectivity, Model reuse
TL;DR: We devise and use different strategies to create strong single-basin ensembles
Abstract: The multi-modal nature of neural loss landscapes is often considered to be the main driver behind the empirical success of deep ensembles. In this work, we probe this belief by constructing various "connected" ensembles which are restricted to lie in the same basin. Through our experiments, we demonstrate that increased connectivity indeed negatively impacts performance. However, when incorporating the knowledge from other basins implicitly through distillation, we show that the gap in performance can be mitigated by re-discovering (multi-basin) deep ensembles in a single basin. Thus, we conjecture that while the extra-basin knowledge is at least partially present in any given basin, it cannot be easily harnessed without learning it from other basins.
Track: Extended Abstract Track
Submission Number: 50