Index: Foundations (Bayesian Experimental Design)

Foundations

Routing Summary

The shared conceptual core of Bayesian experimental design: the origin (Lindley’s measure), the objective (EIG), why it’s hard (nested estimation), and how it extends to sequences (adaptive design). Contains 4 notes.

• The historical origin — Lindley’s 1956 average-information measure, Theorems 1–9, the design rule? → Lindley’s Information Measure
• The design objective — EIG, its four equivalent forms, mutual-information reading? → Expected Information Gain
• Why the EIG can’t be computed directly; the NMC estimator and its slow $\mathcal{O}(C^{-1/3})$ rate? → Nested Estimation and Nested Monte Carlo
• Sequential/adaptive design, incremental EIG, total EIG, greedy myopia? → Sequential and Adaptive BED

Concept Map

Concept	Note	Type	Depends On	Key Result
Lindley’s measure; Defs 1–2; Thms 1–9; partial order; design rule	Lindley’s Information Measure	concept/theorem	Probability and Bayesian Inference	$\mathcal{I}(\mathcal{E},p(\theta ))=E_x[{\mathcal{I}}_1(x)-{\mathcal{I}}_0]$; non-negative, additive, concave
EIG; information gain; mutual-information forms; optimal design	Expected Information Gain	concept/definition	Lindley’s Information Measure	$\mathrm{EIG}(\xi )={\mathbb{E}}_{p(y,\theta \mid \xi )}[\log \frac{p(\theta \mid y,\xi )}{p(\theta )}]={\mathrm{MI}}_{\xi }(\theta ;y)$
Double intractability; NMC estimator; debiasing vs variational	Nested Estimation and Nested Monte Carlo	concept/theorem	Expected Information Gain	NMC is biased ($\mathcal{O}(1/M)$), costs $NM$, rate $\mathcal{O}(C^{-1/3})$ with $M\propto \sqrt{N}$
BAD; incremental EIG; total EIG additivity; greedy myopia	Sequential and Adaptive BED	concept	Expected Information Gain	${\mathrm{EIG}}_{\theta }({\xi }_t\mid h_{t-1})$ with updated prior; $\mathrm{TEIG}={\sum }_t$ incremental EIGs

Notes

• Lindley’s Information Measure — CONTAINS: Shannon→statistics adaptation; information of a distribution (Eqs. 3–5, sign convention); Definitions 1–2 (average information = EIG, Eqs. 6–7); symmetric/mutual-information forms (Eqs. 8–11); Theorems 1–9 (non-negativity, additivity, sufficiency, concavity, diminishing returns, partial order, Blackwell relation); the design rule; worked examples (normal variance, determinant/D-optimality criterion, Wald SPRT, Beta-binomial sequential boundary).
• Expected Information Gain — CONTAINS: InfoGain (Eq. 1) & EIG (Eqs. 2–3) definitions; four equivalent forms / mutual-information theorem; double-intractability argument; decision-theoretic (log-score utility) reading; discrete Rao–Blackwellized estimator.
• Nested Estimation and Nested Monte Carlo — CONTAINS: NMC estimator (Eq. 7) + importance-sampled NMC (Eq. 8); convergence theorem ($\mathcal{O}(C^{-1/3})$, $M\propto \sqrt{N}$, finite-$M$ bias); the two escape routes (MLMC debiasing vs variational approximation); Jensen-bias worked example.
• Sequential and Adaptive BED — CONTAINS: sequential model (Eq. 5); incremental EIG (Eq. 4); total-EIG additivity (Eq. 17); the two flaws of traditional BAD; estimator-compatibility caveat; adaptive psychology / CES examples.

Sources

• Lindley 1956 - On a Measure of the Information Provided by an Experiment.pdf — Lindley, D.V. (1956), On a Measure of the Information Provided by an Experiment, Ann. Math. Stat. 27(4):986–1005. The founding paper.
• Rainforth et al 2023 - Modern Bayesian Experimental Design.pdf — §2 (objectives, BAD), §3.1–3.2 (nested estimation, debiasing)
• Foster et al 2019 - Variational Bayesian Optimal Experimental Design.pdf — §2 (background, NMC, sequential model)
• Foster et al 2020 - Unified Stochastic Gradient BOED.pdf — §2 (background), §3.5 (iterated design)

See Also

• Variational EIG Estimators — the fast estimators that beat NMC
• Decision Analysis — expected-utility framing of the EIG
• Introduction to Bayesian Computation — the inference machinery these methods rely on