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Coarse To Fine Search

Search broadly at a coarse level first, then refine only the most promising regions in more detail.

The Diagnostic Story

Symptom: The team applies high-resolution effort to a large number of candidates before doing any broad screening, exhausting review capacity before the most promising regions are reached. Alternatively, a coarse dashboard is used as a final judgment when it was only meant to guide deeper search. Either way, high-value options are missed, premature commitment locks in early choices, and nobody can explain why certain candidates received detailed attention and others were ignored.

Pivot: Define a coarse representation of the full space, use it to identify which regions deserve refinement, concentrate detailed evaluation there, and build in an audit mechanism to detect and recover from false negatives before the screen becomes permanent.

Resolution: Search cost drops because detailed evaluation is reserved for promising regions, not the entire space. The original search boundary stays visible so attention never becomes unfairly narrow. Final choices rest on high-resolution evidence where stakes require it, not only on the coarse screen.

Reach for this when you hear…

[drug discovery] “We ran full assays on three hundred compounds before screening — we burned the budget before we even got to the likely hits.”

[investigative audit] “I need a quick scan of all the accounts before I commit my forensic team to a handful of suspects, or we will miss the real outliers.”

[urban planning] “The site-selection criteria knocked out eighty percent of parcels in a day — now we do the detailed environmental review on the ten that actually qualify.”

Mechanisms / Implementations

  • Multi-Resolution Search (multi_resolution_search): Implements the archetype by scanning at multiple levels of resolution and escalating detail only where the lower-resolution pass indicates value, uncertainty, or risk.
  • Coarse Grid Search (coarse_grid_search): Implements the archetype in parameter or design spaces by testing a rough grid first, then searching more finely near promising grid regions.
  • Funnel Process (funnel_process): Implements the archetype in review or product workflows by moving many candidates through cheap early screens before detailed evaluation of a smaller set.
  • Diagnostic Narrowing (diagnostic_narrowing): Implements the archetype by starting with broad symptom, signal, or evidence groups and then applying more specific tests to likely diagnostic regions.
  • Portfolio Screening (portfolio_screening): Implements the archetype by using coarse financial, strategic, risk, or feasibility filters before intensive due diligence on selected opportunities.
  • Progressive Candidate Review (progressive_candidate_review): Implements the archetype by reviewing applications, proposals, designs, or options in stages, with deeper review reserved for candidates that pass earlier screens or uncertainty checks.
  • Design Downselection (design_downselection): Implements the archetype in design work by comparing rough concepts first and investing detailed engineering, prototyping, or testing in the most promising concepts.
  • Search Tree Pruning with Refinement (search_tree_pruning_with_refinement): Implements the archetype when a tree or hierarchy is explored shallowly first, then expanded more deeply along selected branches while keeping audit checks for pruned branches.
  • Coarse Grid Search
  • Design Downselection

Abstractions this archetype builds on — directly (a source ingredient) or as a related pattern. Links follow the typed catalog namespace.

Built directly on (3)

Also references 7 related abstractions

Variants

Narrower or domain-specific specializations that share this archetype's core structure. Recognized variants are established; candidate variants are provisional.

Multi-Resolution Search · mechanism family variant · recognized

Search across explicit resolution levels, using each level to decide where the next level of detail should be applied.

Coarse Grid Search · implementation variant · recognized

Evaluate a rough grid of possibilities first, then search finer neighborhoods around promising coarse cells.

Funnel Screening · implementation variant · recognized

Move many candidates through cheap early screens, then reserve deeper review for candidates that pass or remain uncertain.

Diagnostic Narrowing · domain variant · recognized

Start with broad diagnostic categories and selectively apply finer tests to the most plausible or highest-risk possibilities.