15 research outputs found
A Too-Good-to-be-True Prior to Reduce Shortcut Reliance
Despite their impressive performance in object recognition and other tasks under standard testing conditions, deep networks often fail to generalize to out-of-distribution (o.o.d.) samples. One cause for this shortcoming is that modern architectures tend to rely on ǣshortcutsǥ superficial features that correlate with categories without capturing deeper invariants that hold across contexts. Real-world concepts often possess a complex structure that can vary superficially across contexts, which can make the most intuitive and promising solutions in one context not generalize to others. One potential way to improve o.o.d. generalization is to assume simple solutions are unlikely to be valid across contexts and avoid them, which we refer to as the too-good-to-be-true prior. A low-capacity network (LCN) with a shallow architecture should only be able to learn surface relationships, including shortcuts. We find that LCNs can serve as shortcut detectors. Furthermore, an LCN’s predictions can be used in a two-stage approach to encourage a high-capacity network (HCN) to rely on deeper invariant features that should generalize broadly. In particular, items that the LCN can master are downweighted when training the HCN. Using a modified version of the CIFAR-10 dataset in which we introduced shortcuts, we found that the two-stage LCN-HCN approach reduced reliance on shortcuts and facilitated o.o.d. generalization
The UEFA Champions League seeding is not strategy-proof since the 2015/16 season
Fairness has several interpretations in sports, one of them being that the
rules should guarantee incentive compatibility, namely, a team cannot be worse
off due to better results in any feasible scenario. The current seeding regime
of the most prestigious annual European club football tournament, the UEFA
(Union of European Football Associations) Champions League, is shown to violate
this requirement since the 2015/16 season. In particular, if the titleholder
qualifies for the first pot by being a champion in a high-ranked league, its
slot is given to a team from a lower-ranked association, which can harm a top
club from the domestic championship of the titleholder. However, filling all
vacancies through the national leagues excludes the presence of perverse
incentives. UEFA is encouraged to introduce this policy from the 2021-24 cycle
onwards.Comment: 11 pages, 1 figure, 1 tabl