Constrained convex p-value weighting in monotone likelihood ratio families (Princessp)
Mathematical Methods AIMech:ConstrainedConvexPValueWeightingInMonotoneLikelihoodRatioFamilies DRAFT
Aliases: Princessp, Prior-Informed Convexly Constrained Spjotvoll P-Value Weighting, Order- and Box-Constrained Convex P-Value Weighting, Monotone Likelihood Ratio Convex P-Value Weighting
A convex-optimization p-value weighting methodology (Princessp: 'PRior-INformed, Convexly Constrained Spjotvoll') introduced by Edgar Dobriban (2018, Information and Inference: A Journal of the IMA 7(2):251-275, arXiv:1603.05334v2, DOI:10.1093/imaiai/iax013) for testing massive collections of J hypotheses H_{0,j}: theta_j = theta_{0,j} against H_{a,j}: theta_j = theta_{a,j} at per-test significance level q in (0, 1) using p-values P_j and prior weights w_j >= 0 with J^{-1} sum_{j=1}^J w_j = 1 (controlling the family-wise error rate via weighted Bonferroni P_j <= q w_j or the false discovery rate via weighted Benjamini-Hochberg). By re-parametrizing the power of the j-th test in terms of the p-value threshold u_j = q w_j as the receiver operating characteristic (ROC) function R_j(u_j) = F_{a,j}(F_{0,j}^{-1}(u_j)) rather than the non-concave critical-value parametrization c_j = F_{0,j}^{-1}(q w_j), Dobriban proves that R_j(u_j) is concave on [0, 1] whenever the test statistic comes from an absolutely continuous parametric family with monotone likelihood ratio (MLR) for one-sided tests (Proposition 2.1) or from a canonical exponential family for two-sided equal-tailed tests |T_j| >= z(u_j/2) (Proposition 2.2), where unconstrained two-sided Gaussian weights take the closed form w_j^* = 2 q^{-1} Phi(-|mu_j|/2 - |mu_j|^{-1} arccosh(lambda exp(mu_j^2/2))) (Proposition 2.3). Because unconstrained Spjotvoll weights become non-monotone in |mu_j| when q exceeds a critical level (assigning less weight to the largest effect sizes; Propositions 3.1-3.2) and place zero weight on small prior effects, Princessp maximizes J^{-1} sum_{j=1}^J R_j(q w_j) subject to the convex constraint set C = {w in R^J : J^{-1} sum_{j=1}^J w_j = 1, l <= w_j <= u, w_1 <= w_2 <= ... <= w_J} for hypotheses sorted by increasing |mu_j|, enforcing effect-size monotonicity and non-zero minimum weights l in (0, 1] via an O(J)-step interior-point Newton solver whose barrier Hessian + order-constraint KKT matrix reduces to a symmetric tridiagonal-plus-rank-1 system solved in O(J) time via the Sherman-Morrison formula combined with hybrid subsampling for large J.
Identity Notes & Concept Scope
No normalized identity match for Constrained convex p-value weighting in monotone likelihood ratio families (Princessp) across all 442 pinned AIO records and 591 maintained IDs, names, aliases and scoped synonyms. Only frontier reference matches in Round 194-196 discovery artifacts were found. Distinct from AIMech:BayesOptimalPValueWeightingUnderGaussianPrior (Dobriban, Fortney, Kim, & Owen 2015), which models uncertain Gaussian priors mu_i ~ N(eta_i, sigma_i^2) on one-sided Gaussian means and solves an unconstrained non-convex marginal power optimization via quadratic-root critical values and jump-discontinuity sorting, whereas Dobriban (2018) proves concavity of the ROC function R_j(q w_j) across general monotone likelihood ratio (MLR) families and two-sided exponential-family tests (Propositions 2.1-2.3), proves non-monotonicity of unconstrained Spjotvoll weights in |mu_j| for moderate q (Propositions 3.1-3.2), and formulates Princessp to maximize average ROC power under linear order constraints w_1 <= ... <= w_J and box bounds l <= w_j <= u via an O(J) tridiagonal-plus-rank-1 interior-point solver (Section 4.2); and distinct from AIMech:OptimalMultiWeightedStepUpProcedureForFDRControl (Roquain & van de Wiel 2009) and AIMech:AdaptiveDataDrivenOptimalPValueWeighting (Durand 2019).
Claims & Grounded Evidence
4 Claims
Mechanism
#roc-reparametrization-concavity-in-mlr-families
Whereas the critical-value parametrization c_j -> 1 - F_{a,j}(c_j) subject to J^{-1} sum_{j=1}^J (1 - F_{0,j}(c_j)) = q is non-convex (neither concave nor convex even in the Gaussian shift model), re-parametrizing power in terms of the per-test significance threshold u_j = q w_j via the receiver operating characteristic (ROC) function R_j(u_j) = 1 - F_{a,j}(F_{0,j}^{-1}(1 - u_j)) (for upper-tail tests) or F_{a,j}(F_{0,j}^{-1}(u_j)) (for lower-tail tests) yields a concave function on [0, 1] with derivative R_j'(u_j) = f_{a,j}(F_{0,j}^{-1}(1 - u_j)) / f_{0,j}(F_{0,j}^{-1}(1 - u_j)) whenever the test statistic comes from an absolutely continuous parametric family {F_theta} with monotone likelihood ratio (MLR) and theta_{a,j} > theta_{0,j} (Proposition 2.1, Section 6.1), reducing optimal p-value weighting under any convex constraint set C to a convex optimization problem.
Mechanism
#two-sided-exponential-family-concavity-and-closed-form-gaussian-weights
For two-sided tests rejecting H_{0,j}: theta_j = 0 in favor of theta_j != 0 when |T_j| >= z(u_j/2) with F_0(z(u)) = 1 - u in a canonical one-parameter exponential family f_theta(t) = exp(theta t - A(theta)) f_0(t), the two-sided ROC function R_theta(u) = 1 - F_theta(z(u/2)) + F_theta(-z(u/2)) has derivative R_theta'(u) = (1/2)[f_theta(z(u/2))/f_0(z(u/2)) + f_theta(-z(u/2))/f_0(-z(u/2))] = exp(-A(theta)) cosh(theta z(u/2)), which is non-increasing on [0, 1] because u -> z(u/2) >= 0 is decreasing and cosh(|theta| x) is increasing on [0, infinity), establishing concavity of R_theta(u) on [0, 1] (Proposition 2.2, Section 6.2); in particular, for the two-sided Gaussian model T_j ~ N(mu_j, 1) with mu_j != 0, whenever J^{-1} sum_{j=1}^J Phi(-|mu_j|/2) >= q/2, the unconstrained Spjotvoll two-sided optimal weights are given in closed form by w_j^* = 2 q^{-1} Phi(-|mu_j|/2 - |mu_j|^{-1} arccosh(lambda exp(mu_j^2/2))), where lambda > 1 is the unique root of J^{-1} sum_{j=1}^J w_j(lambda) = 1 (Proposition 2.3, Section 6.3).
Mechanism
#spjotvoll-non-monotonicity-at-moderate-significance-levels
In the Gaussian shift model with distinct non-zero prior effect sizes |mu_j|, there exists a critical significance threshold q_0 > 0 such that the unconstrained Spjotvoll weight vector w^* is strictly increasing in |mu_j| (both one-sided for mu_j < 0 and two-sided for mu_j != 0) for all q <= q_0 (Proposition 3.1, Section 6.4), whereas for larger q > q_0 when dual multiplier lambda > 1, the weight function mu -> w^*(mu) is unimodal on (-infinity, 0): it increases from 0 at mu = 0 to a peak at the negative root mu = -sqrt(2 log lambda) of mu^2/2 - log lambda = 0 (one-sided) or at the unique root mu = -sqrt(a^*) of a - 2 tanh(a/2 + acosh(lambda exp(a/2))) acosh(lambda exp(a/2)) = 0 (two-sided, Proposition 3.2, Section 6.5) and then decreases to Phi(0)/q = 1/(2q) as |mu| -> infinity, paradoxically assigning smaller weights to the largest prior effects than to intermediate prior effects.
Mechanism
#princessp-order-and-box-constrained-tridiagonal-rank1-solver
To eliminate both the non-monotonicity of unconstrained Spjotvoll weights at moderate q and the fragility of assigning zero weight to underestimated effects, Princessp (Section 3.1 & Section 4.1–4.2) sorts hypotheses by |mu_1| <= |mu_2| <= ... <= |mu_J| and maximizes J^{-1} sum_{j=1}^J R_j(q w_j) over the convex polytope C = {w in R^J : J^{-1} sum_{j=1}^J w_j = 1, l <= w_j <= u, w_1 <= w_2 <= ... <= w_J} with lower bound l in (0, 1] and upper bound u >= 1; in the log-barrier interior-point method minimizing t f_0(w) + sum_{k=1}^{J+1} phi_k(w) subject to 1^T w = J, the barrier Hessian H is symmetric tridiagonal (because each constraint w_k - w_{k+1} <= 0 couples only adjacent indices), so the Newton KKT system [[H, 1], [1^T, 0]] [Delta w; nu] = [-g; 0] decomposes into two tridiagonal linear solves H x = -g and H y = 1 combined via the Sherman-Morrison formula nu = (1^T x)/(1^T y) and Delta w = x - nu y in O(J) arithmetic operations per Newton step (Section 4.2.1), while a hybrid subsampling and linear-interpolation scheme resolves numerical ill-conditioning from active equality clusters when J is large (Section 4.2.2).
⚠️ Curated Limitations & Negative Results
- Concavity of the receiver operating characteristic (ROC) objective R_j(q w_j) requires continuous test statistics with monotone likelihood ratio (Proposition 2.1) or canonical exponential-family structure for two-sided equal-tailed tests (Proposition 2.2); discrete test statistics produce piecewise-constant step-function ROC curves that are not concave (Section 2.1), and non-MLR heavy-tailed models such as the Cauchy shift family violate concavity (Section 2.1).
- In the log-barrier interior-point solver (Section 4.2.1–4.2.2), adjacent weights that are equal at the constrained optimum (w_k^* = w_{k+1}^*) force the barrier Hessian entries (w_{k+1} - w_k)^{-2} -> infinity as the barrier parameter t increases, causing numerical ill-conditioning for large J > 10^3 that requires solving the convex program on a grid/subsample of size S ~ 500 and linearly interpolating the resulting monotone weight function (Section 4.2.2).
- Princessp optimizes weights assuming point estimates mu_j of the prior effect sizes and requires user specification of the lower bound l in [0, 1] and upper bound u >= 1 (typically l in {0.1, 0.25, 0.5}); when prior effect estimates have known heterogeneous standard errors sigma_j > 0 in a Gaussian model without order constraints, analytical Bayes p-value weighting (Dobriban et al. 2015) directly integrates over the Gaussian prior uncertainty.
- All 962 lines of Dobriban (2018, Information and Inference: A Journal of the IMA 7(2):251-275, arXiv:1603.05334v2, DOI:10.1093/imaiai/iax013) were read. Constructed numerical checks in research/discovery/constrained-convex-p-value-weighting-in-monotone-likelihood-ratio-families-boundaries.py verify (1) Proposition 2.1 ROC concavity in Gaussian shift and Exponential scale MLR families (gaussian_roc_strictly_concave = True, exp_mlr_strictly_concave = True) versus non-concavity of the critical-value parametrization (second derivative at c = -3 is +0.241971 > 0) and discrete Bernoulli step ROC (bernoulli_step_roc_non_concave = True), (2) Propositions 2.2 & 2.3 two-sided exponential-family concavity and exact closed-form two-sided Gaussian arccosh weights (lambda^* = 0.08047, budget error = 0.0, max KKT stationarity error = 9.71445146547012e-17), (3) Propositions 3.1 & 3.2 small-q monotonicity at q = 4e-06 (monotone = True) versus moderate-q non-monotonicity at q = 0.001 where w^*(|mu|=3.5) = 1.16198 < w^*(|mu|=2.2) = 2.375011 and Proposition 3.2 two-sided mode a^* = 230.464399 (root error = 2.6645352591003757e-15), and (4) Section 4.2 Princessp O(J) tridiagonal-plus-rank-1 Sherman-Morrison KKT solver (KKT residual = 4.6629367034256575e-15, order and box constraints satisfied = True / True, active-tie barrier curvature max H = 1.24e+10, and power on an underestimated true signal mu_true = -2.5 improved from 0.0 under Spjotvoll to 0.391248 under Princessp with l = 0.5).
Artificial Intelligence Ontology (AIO) Grounding
Mapped AIO Classes
| AIO Target Class | Mapping Relation | Mapping Rationale |
|---|---|---|
AIO:DataDredgingBias
Data Dredging Bias
|
related_match | Constrained convex p-value weighting (Princessp) allocates monotone, box-bounded per-hypothesis significance thresholds q w_j using prior effect-size estimates while strongly controlling frequentist family-wise error rate or false discovery rate to prevent multiplicity-induced false positives (AIO:DataDredgingBias). |
Evidence Sources & Primary Literature
3 Sources| Source ID | Publication / Document | Type / Access | Reference & Checksum |
|---|---|---|---|
dobriban2018-princessp-ar5iv
|
Edgar Dobriban
|
primary paper
full_text
|
ID: https://doi.org/10.1093/imaiai/iax013
sha256:2cb5aec839dc…
|
dobriban2018-princessp-crossref
|
Edgar Dobriban
|
primary paper
abstract_only
|
ID: https://doi.org/10.1093/imaiai/iax013
sha256:8c16d847b555…
|
dobriban2018-princessp-abs
|
Edgar Dobriban
|
primary paper
abstract_only
|
ID: https://doi.org/10.48550/arXiv.1603.05334
sha256:b43dd4a2f163…
|
Ontology & Grounding Topology
Open in interactive network graph →Curation Provenance
Curator: Antigravity
Method: ai_assisted
Model: Gemini 3
Created: 2026-10-17T15:15:00Z
Updated: 2026-10-17T15:15:00Z
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