Sparse Expectation Maximization

Identity Notes & Concept Scope Sparse denotes selective posterior work in the Neal-Hinton construction, not sparse model weights, pruning or setting excluded states to zero. It differs from incremental EM’s selection of observations and can be combined with that method. It is also distinct from restricting a variational posterior to independent chain factors or permanently imposing a truncated support. No normalized identity matches among 442 pinned and 476 maintained records, including acronym probes. GEM is the exact-current-E/Q-improvement framework, IEM refreshes cached independent cases, sparse EM preserves frozen outside mass, and DAEM is the warm-started cooling-to-beta1 procedure. Existing TEM has the same finite-state fixed-beta update, but its broader update framework and held-out inverse-annealing realization do not define that outer cooling procedure. ECM, AECM and SAGE specialize parameter/augmentation updates, not these case or probability-subset operations. Structured factorial-HMM variational inference imposes a different family restriction. Names and incidental frontier references do not establish identity; qualified GEM/IEM aliases avoid unrelated uses. The absence assessment is bounded to this snapshot and corpus. Identity-search counts: 253 matched lines in the worktree and 260 in main; all 98 distinct matching-text windows were read, with ignored and hidden files included.