Adaptation sampling
Algorithms AIMech:AdaptationSampling DRAFT
An online optimizer-hyperparameter controller that compares sample quality under a current and a hypothetical setting, using either fresh evaluations or importance-weighted reuse of existing observations, to decide how to adapt the setting.
Identity Notes & Concept Scope
Adaptation sampling denotes the online optimizer-hyperparameter comparison controller, with direct fresh-sample and virtual density-ratio-reuse modes. It differs from baseNES/xNES/SNES/IGO updates, CMAevolutionpaths, Rpropgradient-sign control and population-based training. xNES-as is the composed optimizer, not an alias. Current733native442AIO inventory and four ignored-inclusive checkout scans found no equivalent identity; preserve existingowner195. Current committed331 assessment covers733native and442pinnedAIO records: all1175 identity/definition/hash rows equal the accepted natural-gradient research inventory. Four combined rg --no-ignore --hidden scans reconcile4491occurrences in196unique line contents. Earlier supporting assessments cover167 retained contents; root read all29 newly observed contents, including new331 generated pages/review and hyphenated adaptation-sampling exclusions. The initial oversized display was recovered with a bounded read of items13–20. All new contexts describe established NES/IGO/xNES/SNES or reserve the proposed methods; none supplies an equivalent maintained record. All908main393nested frontier objects retain the331 predecessor; root reassesses owners193–196/203 and retained broader supporting semantic/frontier/AIO readings. Original natural-gradient2997match and adaptation1456match assessments remain separately attributed, not claimed as fresh full root reread. Actual merge/base and prewrite searches must be verified before creation; no universal absence or saturation.
Claims & Grounded Evidence
6 Claims
Mechanism
#direct-hyperparameter-comparison
Given an algorithm setting theta, a sampling law pi_theta and a quality measure psi for its samples, direct adaptation sampling evaluates fresh samples under a nearby hypothetical setting theta_prime. It retains the new setting when the chosen quality comparison indicates sufficient improvement and otherwise reverts. The comparison acts at the algorithm-hyperparameter level, with progress over time as its motivation; it is not itself the base optimizer’s natural-gradient update. The source gives a Mann–Whitney comparison as an example, not a complete universal testing protocol.
Mechanism
#virtual-density-ratio-reuse
Virtual adaptation sampling reuses samples z_i drawn under pi_theta. It compares their existing quality values once with unit weights and once with weights w_i_prime = pi_theta_prime(z_i) / pi_theta(z_i). The weights represent the hypothetical law while the observed quality values remain unchanged. This can avoid fresh quality evaluations for the comparison, but the two groups reuse the same observations and are not independent samples.
Mechanism
#reported-weighted-rank-comparison
For quality values s_i and s_j_prime with positive weights w_i and w_j_prime, the thesis defines U as the sum of w_i*w_j_prime over pairs with s_i greater than s_j_prime, plus half that product for equal values. It sets m = sum_i w_i and m_prime = sum_j w_j_prime, then uses mu = m*m_prime/2 and variance m*m_prime*(m+m_prime+1)/12 in a normal comparison. These are the source’s reported weighted-statistic and approximation formulas. They do not establish nominal independent-sample calibration for the paired, importance-weighted virtual mode.
Mechanism
#nes-counterfactual-scale-learning-rate
In the concrete NES application, the controller adapts the learning rate eta_sigma of the global search scale. It forms the hypothetical distribution that would result from the previous optimizer state using 1.5 times the current eta_sigma, then weights the current population by the hypothetical-to-actual density ratio and compares its fitness ranks with their weighted counterpart. The hypothetical learning-rate change is distinct from directly multiplying the current search scale by 1.5 or adapting every optimizer block learning rate.
Mechanism
#empirical-increase-or-return-policy
The described NES policy starts from a conservative initial learning rate. When its improvement criterion succeeds, it sets eta_sigma_new = min((1+c_prime)*eta_sigma, 1); otherwise it sets eta_sigma_new = (1-c_prime)*eta_sigma + c_prime*eta_sigma_init. The reported defaults are c_prime = 0.1 and rho = 1/2 - 1/(3*(d+1)) for search dimension d. These are empirical controller settings, not optimality or nominal error-rate guarantees. The unspecified test-return and rank-orientation conventions in the displayed pseudocode remain explicit limitations.
Scope
#modes-and-composition-boundary
The source distinguishes direct fresh-evaluation adaptation from virtual reuse and also discusses combining reweighted observations with some new hypothetical-law samples of weight one. Fresh sampling and reuse are therefore explicit modes, not interchangeable implementations. The 2012 paper calls the combination of xNES with the controller xNES-as. That combined optimizer, generic importance sampling, importance mixing and the weighted comparison statistic are not exact aliases of the adaptation-sampling controller.
⚠️ Curated Limitations & Negative Results
- The weighted normal approximation is not established as calibrated for reused importance-weighted groups. In the equal-law case with finite ratios equal to one, both groups contain the same n quality values. Pair symmetry, including ties, makes U=n²/2 deterministically, whereas the displayed substituted variance is n²*(2*n+1)/12>0 for n>0. This bounded curator derivation refutes that expression as the actual variance in this paired case; it is not an author-issued erratum, a general error-rate calculation or a claim that every independent direct-sampling test is invalid.
- The thesis Appendix B gives half credit for equal values but displays no tie-adjusted variance. Integer weights as repeated observations explain the pair-count identity, not independence or valid variance. Adaptive choice of the hypothetical law, repeated comparisons and dependence between the reused groups require separate calibration. Empirical rho is not asserted to be a valid nominal significance level.
- The thesis and journal prose attach weights to unchanged quality values. The 2012 Algorithm 2 and 2014 Algorithm 4 instead write a set containing weight times rank, which must not silently be implemented as altered rank values. Their weighted-Mann-Whitney return value and rank/tail convention are not fully specified; the threshold branch is not certified as a literal implementation of the thesis’s directional normal comparisons. No repaired pseudocode or author-code behavior is claimed.
- Ratios need finite, positive sampling densities at reused observations and defined finite hypothetical densities. Representing hypothetical-law expectations also requires suitable proposal coverage and integrability; positivity only at observed points does not establish global support coverage or stable weights. Large distribution changes can create large as well as small ratios. A weighted finite batch need not reveal an improvement, and no automatic effective-sample-size or numerical safeguard is supplied.
- Direct mode spends fresh evaluations, while virtual mode reuses expensive quality observations and still needs hypothetical-density evaluation and comparison work. The optional interpolation using fresh samples is not required in every mode. No cost-free controller, general variance reduction, monotonic progress, convergence, universal noise robustness or benchmark advantage is asserted.
- The concrete NES rule concerns the global-scale learning rate and empirical defaults. It is distinct from xNES or SNES themselves, natural-gradient geometry, IGO flow, CMA-ES evolution-path control, Rprop gradient-sign updates and population-based model copying. The source’s increase/decrease analogy with Rprop does not establish an exact alias. Underlying full-covariance NES formulas are not re-certified by this controller description.
- Primary reading is limited to the declared methods and context: the thesis Section 2.4.4 and Appendix B, journal Section 3.2, and the 2012 Section 2.2/Algorithm 2 and defaults. The thesis body incorrectly points to Appendix A; the acquired 134-page author copy places the weighted test in Appendix B, PDF p. 121 / printed p. 97. Its cover dates and the separately inspected TUM repository metadata are retained without claiming byte equivalence to the repository PDF. The full thesis and empirical figures/tables were not audited.
- The 2012 proceedings paper notes that its use of the known target fitness for restart decisions was outside the BBOB guidelines; its numerical comparisons are not imported here. Its initial sandbox DNS download failure and separate successful retry remain in the research provenance. An author BibTeX fetch was unsupported by the web tool. No author implementation, benchmark, statistical test or calculator was executed for this controller assessment.
Artificial Intelligence Ontology (AIO) Grounding
Explicit AIO Snapshot Assessment: No Match
Rationale: No inspected pinned target supplies a sufficiently informative identity or necessary defining-component relation for the general comparison-based controller. Optional learning applications and host-optimizer components do not justify forcing a mapping.
Search Scope: Current733native442pinnedAIO inventory and all scoped synonyms were reconciled at committed331head32760a0e5b75bbc3187aa1ae2ed2ed71f499ae9f. Four combined ignored/hidden-inclusive scans yielded4491occurrences in196distinct contents; retained supporting readings cover167, with all29 new contexts read by root. Earlier adaptation-specific reading covered88definitions,nine full native neighbors,13exactAIOCLASSnodes and74incidentedges; root inspected all13nodes/74edges. All908main393nested frontier objects were mechanically scanned in retained research;95relevantlabels/five fullowners were read, and currentowners193–196/203 were reassessed. Existingowner195 remains the sole controller lead. This bounded pinned-snapshot assessment is not global absence or literature saturation; actual merge-based creation freshness is recorded separately.
| Examined AIO Candidate | Rejection Reason |
|---|---|
AIO:MetaLearning
|
The source uses meta-learning in a broad optimizer-control sense. The pinned target specifically concerns metadata about machine-learning experiments; that scope is not inherent to this general controller. |
AIO:TrainingStrategy
|
The pinned definition concerns model training and preprocessing. The controller can adapt black-box search without training a machine-learning model. |
AIO:MathematicalFunction
|
The pinned definition is broad and is not restricted to scalar functions. Generic computational describability supplies no sufficiently informative identity or necessary specific-component match for this family of sampling, comparison and controller procedures. |
AIO:ExponentialFunction
|
Scalar exponentiation is a component of a possible underlying NES update, not a mandatory defining operation of the general adaptation-sampling controller. |
AIO:ReinforcementLearning
|
A possible policy-search application does not make an environment/reward learning interface inherent to the controller. |
AIO:ProbabilisticHiddenLayer
|
Evaluating sampling densities does not supply a predictive category-estimation hidden layer. |
AIO:SelectionAndSamplingBias
|
Coverage and calibration problems are limitations of a comparison, not an identity mapping to a bias category. |
AIO:ActiveLearning
|
Extra objective or quality evaluations do not inherently constitute interactive labeling or a predictive query-selection task. |
AIO:KnowledgeTransfer
|
Reusing evaluations within a search is not inherently transfer of knowledge between entities. The target’s related Adaptation synonym does not establish equivalence. |
AIO:MetaLearningLLM
|
No language model, pretrained prior or few-shot task-adaptation mechanism is required. |
AIO:EvolutionaryLLM
|
No language model is required; the related evolutionary algorithms synonym does not identify this controller. |
AIO:RegularizationLayer
|
No layer-specific parameter or activity penalty is required. |
AIO:MachineLearningTask
|
The controller can operate on arbitrary black-box search. Adapting optimizer settings does not by itself identify the pinned task of building methods that learn from data. |
Evidence Sources & Primary Literature
3 Sources| Source ID | Publication / Document | Type / Access | Reference & Checksum |
|---|---|---|---|
schaul2011-thesis
|
Tom Schaul
|
author technical report
full_text
|
sha256:788a40bc471c…
|
wierstra2014
|
Daan Wierstra, Tom Schaul, Tobias Glasmachers, Yi Sun, Jan Peters, Jürgen Schmidhuber
|
primary paper
full_text
|
sha256:80ec84951836…
|
schaul2012
|
Tom Schaul
|
primary paper
full_text
|
sha256:ef2d3e54ebf7…
|
Curation Provenance
Curator: Codex
Method: ai_assisted
Model: GPT-6
Created: 2026-10-15T05:26:04Z
Updated: 2026-10-15T05:26:04Z
Source File:
data/curated/AdaptationSampling.yaml