JISC/NSF PI Meeting, June Archon - A Digital Library that Federates Physics Collections with Varying Degrees of Metadata Richness Department of Computer Science Old Dominion University, Norfolk, VA K. Maly, M. Zubair, M. Nelson In Collaboration With Los Alamos National Laboratory (R. Luce) & American Physical Society (M. Doyle)

Motivation Lack of a federation service that provides an unified interface to diverse collections in the physics domain having metadata that differ in richness, syntax, and semantics

Motivation Dissemination and discovery of Physics resources Contributors LANL, APS, AIP, CERN researchers, teachers Users Students, teachers, researchers

Arc: The Basic Federation Engine

Challenges Resource Discovery –Diversity in metadata richness –Lack of controlled vocabulary –Ease of discovering (formula based discovery) –Cross linking support –Classification Creation and Maintenance –Freshness of metadata –Dynamic nature of collections –Filtering Economic Sustainability –Rights management –Who pays? For what?

Issues – No controlled vocabulary Different subject classifications Same authors but different rendering Same affiliation but different form

Interactive resource discovery approach components

Issues - Equation based search Representing search query Rendering of equations and embedding them into the HTML display Integrating into search interface Identifying equations inside the metadata Filtering equations Equation storage

Filtering Equations Errors in equation encoding, some examples: – missing "$" in LaTeX representation – illegal LaTeX symbols Simple equations like "n=3"

Filtering/categorizing Equations Approach: Use of "Stop Equation File" similar to "Stop Word File" used for indexing. In equation filtering context, the stop equation file consists of rules in form of regular expressions, which describe the LaTeX string to be dropped. The regular expression approach gives us the flexibility to describe easily variety of strings to be filtered.

How to search for records using equations? Three search alternatives (or any combination of these) for the user: Search for docs containing all formulae found in a) abstracts b) subject fields of documents containing user input ‘keywords’ Search for docs containing formulae defined by category (e.g. integrals, moments, limits) Browse formulae by various categorizations and search for docs containing selected formulae

Issues - Cross Linking References Obtaining references from full-text documents or parallel metadata sets Bad format of such references when obtained from full text Needed standard way to represent across collections

Issues – Name similarity Authors use different names for themselves and their affiliation Could use authority files, difficult to create and maintain across different collections

Similarity approach Clustering Iterative refinement approach: Coarse level clusters based on approximate string matching (edit-distance, soundex, n-gram) Refining clusters based on affiliation where available Presentation Allow user to follow search by clicking authors and then selecting appropriate, i.e., no authority files

Homogenizing User Space Enabling Web users to discover information in OAI collections (DP-9 Service) – Enabling OAI users to discover information in Web enabled non-OAI compliant collections/databases/web sites

DP-9 Service for Exposing OAI Collections to Web

Web Enabled Non-OAI Compliant Collections/Databases/ Web Sites Web Enabled Non-OAI Compliant Collections/Databases/ Web Sites Web Enabled Non-OAI Compliant Collections/Databases/ Web Sites OAI Service Provider Gateway to Non-OAI Collections WIDL Description (XML based language) WIDL Description (XML based language) WIDL Description (XML based language) Vac: Gateway Service for Harvesting Non-OAI Collections

Sample Description in WIDL of a Web enabled Non-OAI Collection

Federation/archives Consistency

Future Tasks Post processing of search results for easier navigation Exploiting richer metadata and handling diversity in metadata across all participating collections Concentrate on interactive search interface for resource discovery Data normalization, authority files, filtering Investigating different schemes for maintaining federation/archives consistency More high level services beyond formula based search and cross-linking User testing!!!!

Links ODU DL research group: – Main federation engine: – NSDL research: – ITR/IM research –

Not used

Automated metadata mapping approach