Federated v. Aggregated A debate. Keith Ewing MnPALS User Groups Meeting 28 October 2008

The Problem Information is scattered. Information is scattered. Internal Catalog of physical materials Local digital collections and assets Public and vended data providers Multiple content sources Frequently duplicated content External Requiring multiple search interfaces User confusion and frustration

What users want then sort, rank, and show me the first 10 scholarly, peer- reviewed, full-text, accessible, easy-to-read, results Search everything: GOOGLZONGOOGLZON

Federated Search (MetaSearch) User Search DB1 DB2 DB3 DB4 DB5 Broadcast Retrieve Collect Sort De-Dup

Aggregated Search (Google-ized) Search Harvest Crosswalk Index De-Dup DB1 DB2 DB4 DB5 User DB3 Display

Head-to-Head Sources: External/OAI/Web Sources: External/OAI/Web Aggregate: at search Aggregate: at search Minimal bandwidth, but searches can be slowed by Internet congestion Minimal bandwidth, but searches can be slowed by Internet congestion Content updates by vendor may be in real time Content updates by vendor may be in real time Authentication with query Authentication with query Screen-scraping  weak results Screen-scraping  weak results Relevance ranking uneven due to multiple vendors Relevance ranking uneven due to multiple vendors Uneven delays in retrieval Uneven delays in retrieval Sources: Internal/Negotiated external Sources: Internal/Negotiated external Aggregate: at index Aggregate: at index High bandwidth for harvest, lower for search, but high hardware storage costs High bandwidth for harvest, lower for search, but high hardware storage costs Content updates dependent on harvest timing Content updates dependent on harvest timing Authenticate to access Authenticate to access Metadata  stronger results Metadata  stronger results Consistent relevance ranking Consistent relevance ranking No delay in retrieval No delay in retrieval FederatedAggregated

A debate with no winner Depends on what you want/need Depends on what you want/need Each has its use Each has its use Analyze what you want/need Analyze what you want/need What works for one library may not work for a consortium What works for one library may not work for a consortium Neither will solve all problems alone Neither will solve all problems alone Probably need both Probably need bothBut…

As students change… Will they understand the difference? Will they understand the difference? Will teaching the difference be enough to change behaviors? Will teaching the difference be enough to change behaviors?