T.Sharon-A.Frank 1 Internet Resources Discovery (IRD) Types of Digital Libraries

2 T.Sharon-A.Frank Contents Types of DLs Comparisons Additional Aspects

3 T.Sharon-A.Frank Sample list of Digital Libraries LOC - Library of Congress American Memory ( ) NSDL - National Science DL ( ) IPL - Internet Public Library ( ) CDL - California DL ( ) ADL – Alexandria DL ( ) BL - British Library ( NZDL – New Zealand DL ( ) Einstein Archives Online (

Types of DLs

5 T.Sharon-A.Frank Basic SE (BSE) Meta SE (MSE) Popularity SE (PSE) Stand Alone DL (SDL) Harvested DL (HDL) Federated DL (FDL) Digital Library (DL) Search Engine (SE) Directory (Catalog, Guide, Subject Gateway) Web Repositories Hierarchy

6 T.Sharon-A.Frank Types of DLs Stand-alone Digital Library (SDL) – also self-contained, several collections Federated Digital Library (FDL) – also confederated, networked Harvested Digital Library (HDL) – also distributed

7 T.Sharon-A.Frank Exemplary Digital Libraries Stand Alone DL (SDL) Library of Congress (LC) and National Digital Library (NDL) Internet Public Library (IPL) Snunit Federated DL (FDL) Networked Computer Science Technical Reference Library (NCSTRL) Online Computer Library Center (OCLC) Harvested DL (HDL) SourceBank ( ArticleCentral.com! ( ) Harvest/Katsir, OAI

8 T.Sharon-A.Frank Virtual (Symbolic) (VDL) Metadata Oriented Several SDL (General) Collection General VDL Specialty VDL Library Index Weblog List Real (Physical) Self-contained (SDL) Data-Objects Oriented Single SDL (Specialty) Collection Stand-Alone (SDL) First Generation Digital Libraries

9 T.Sharon-A.Frank Stand-alone Digital Library (SDL) A regular DL Usually localized on server/LAN Self-contained material: – edited/generated – scanned/digitized – purchased Single or Several digital collections

10 T.Sharon-A.Frank Federated Digital Library (FDL) Contains many autonomous libraries Usually heterogeneous repositories Connected via a network Forms a virtual library Unified/Transparent user interface  The major problem is interoperability

11 T.Sharon-A.Frank Harvested Digital Library (HDL) Harvests digital objects, not full DLs. Objects harvested into metadata (protocol was Harvest/SOIF, nowadays OAI). Does not have to contain objects, just metadata/summaries. But has regular DL characteristics.

12 T.Sharon-A.Frank SDL vs. HDL

13 T.Sharon-A.Frank References Academic Info: Digital Library Moving to the Electronic Library Digital Library Definition (ARL at DL SunSITE) Digital library scope What are Digital Libraries UIUC DLI Glossary Digital Libraries: A selected Resource Guide