The inability of users or systems to locate relevant resources within or across discovery layers (catalogs, indexes, search interfaces, harvests) because of missing or poor metadata, broken or stale indexes, faulty interfaces, or blocked ingestion and harvesting processes.

Principle

Discovery requires accurate descriptive metadata, healthy indexing and query services, and interoperable interfaces; if any component degrades, discoverability falls non‑linearly and user search cost, bias, and duplication of effort increase.

Demonstration

Illustrative scenario: Situation — A repository ingest pipeline fails to update the public search index after a batch ingest. Recognition — Newly deposited items do not appear in search results. Action — Researchers cannot find the materials via search and may duplicate work. Consequence — Reduced reuse, elevated redundancy, missed evidence for research or operational decisions, and inequitable access for users relying on discovery tools.

Misapplication

Blaming users for poor query formulation when the underlying index is stale or metadata are absent. The semantic error is locating the cause in user behavior rather than in system shortfalls that remove items from the searchable universe.

Consequence

Hidden or effectively lost resources; increased time and cost to locate materials; skewed metrics and evaluations based on discoverable subsets; potential inequities when some communities or formats are systematically less discoverable.

Reversal

Alternative access paths (direct identifiers, curated lists, citation networks, or targeted API queries) and remediation of metadata and index health can recover discoverability; intentional non‑discovery (dark archives, restricted collections) are cases where lack of discovery is by design rather than failure.

Boundary

Clearly within: broken search index, failed metadata harvest, or non‑ingested records. Boundary case: items discoverable via advanced API calls but not by default search interface. Clearly outside: resources intentionally excluded from discovery (classified or private archives).

Semantic Tension

Discoverability ↔ Confidentiality — enhancing discovery increases access and reuse but may conflict with privacy, confidentiality, or embargo requirements that legitimately restrict discovery.

Synthesis

Discovery failure obscures resources rather than destroying them; effective stewardship therefore requires maintaining not only content and metadata but also the health of indexing, harvesting and interface layers so that preservation yields usable access.