UnsolvedMajor Solve Problem

Multiple Risk Control Beyond Sequential Order: Graph-Structured Dependencies

Posed by Joshi, Sun, Hassani, and Dobriban (2025)

§ Problem Statement

Setup

Let (X,Y,Y)(X,Y,Y^*) denote input, model output, and reference output. For m1m\ge 1 constraints, the source paper defines score functions Sj(X,Y,Y)S_j(X,Y,Y^*) and behavior-cost variables Vj(X,Y,Y)0V_j(X,Y,Y^*)\ge 0 with thresholds λjΛjR\lambda_j\in\Lambda_j\subset\mathbb R. In the sequential formulation (a chain of constraints), the jj-th constraint loss is

Lj(λ1:j)=Vj1{S1λ1,,Sj1λj1, Sj>λj},L_j(\lambda_{1:j})=V_j\,\mathbf 1\{S_1\le\lambda_1,\dots,S_{j-1}\le\lambda_{j-1},\ S_j>\lambda_j\},

and the objective loss is

Lm+1(λ1:m)=Vm+11{S1λ1,,Smλm}.L_{m+1}(\lambda_{1:m})=V_{m+1}\,\mathbf 1\{S_1\le\lambda_1,\dots,S_m\le\lambda_m\}.

The population target is

minλ1Λ1,,λmΛm ELm+1(λ1:m)s.t.ELj(λ1:j)βj  (j[m]).\min_{\lambda_1\in\Lambda_1,\dots,\lambda_m\in\Lambda_m}\ \mathbb E L_{m+1}(\lambda_{1:m}) \quad\text{s.t.}\quad \mathbb E L_j(\lambda_{1:j})\le \beta_j\ \ (j\in[m]).

The paper introduces a dynamic-programming baseline (MRBase) and a finite-sample, distribution-free risk-controlling algorithm (MultiRisk) for this sequential dependence structure.

Unsolved Problem

Extend finite-sample distribution-free multiple-risk control from the current sequential (totally ordered) dependence to general graph-structured dependence among risks. Formally, let G=(V,E)G=(V,E) be a directed acyclic graph on V=[m]V=[m], with parent sets pa(j)\mathrm{pa}(j). Define graph-triggered events Ej(λ)E_j(\lambda) from parent conditions and local score thresholds (the sequential case is the special path graph). Develop an algorithm that, for all j[m]j\in[m], guarantees

E[Vj1{Ej(λ)}]βj\mathbb E\big[V_j\mathbf 1\{E_j(\lambda)\}\big]\le \beta_j

in finite samples and distribution-free fashion, while keeping the objective risk near-optimal relative to the graph-structured population program, with explicit dependence on graph complexity, sample size, and number of risks.

§ Discussion

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§ Significance & Implications

Real AI safety/quality pipelines often use interacting constraints rather than a strict sequence. Extending MultiRisk to graph-structured dependencies would substantially broaden practical applicability while preserving rigorous risk guarantees.

§ Known Partial Results

  • Joshi et al. (2025): gives finite-sample distribution-free control for multiple sequential constraints and near-optimality results under stated regularity conditions.

  • Joshi et al. (2025): The same source explicitly identifies extension to more general graph-structured dependence among risks as future work.

  • Joshi et al. (2025): Existing conformal risk-control tools provide ingredients for single or structured constraints, but a full finite-sample graph-structured theory with near-optimal objective guarantees is not yet available.

§ References

[1]

MultiRisk: Multiple Risk Control via Iterative Score Thresholding

Sagar Joshi, Yifan Sun, Hamed Hassani, Edgar Dobriban (2025)

arXiv preprint

📍 Section 2 (problem formulation), Sections 4-5 (MRBase and MultiRisk algorithms and guarantees), and Section 7 (Conclusion: open extension to graph-structured dependencies among risks).

[2]

Conformal Risk Control

Anastasios N. Angelopoulos, Stephen Bates, et al. (2024)

arXiv preprint

📍 Distribution-free risk-control methodology motivating single- and multi-constraint conformal calibration.

[3]

Algorithmic Learning in a Random World

Vladimir Vovk, Alexander Gammerman, Glenn Shafer (2005)

Springer

📍 Nested prediction-set and exchangeability principles underlying distribution-free control constructions.

§ Tags