Linking electronic documents and standardisation of URL’s What can libraries do to enhance dynamic linking and bring related information within a distance of “only one click”? Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Theo van Veen Linking digital objects and standardisation of URL’s

What can libraries do? n Standardisation and agreements n Personal linking page (SFX and OpenUrl) n Offer additional query responses in XML n Conversion of references in electronic documents to OpenUrl (DOI, CrossRef) n Local resolution and redirection of OpenUrl n Disclosure of searchable sites (harvesting, OAI-protocol and deep linking) Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Request Response OpenUrl HTML, javascript OpenUrl XML, javascript XML XML, javascript (dynamic) url’s HTML, javascript telnet,VT100 ASCII Z39.50 scripting screensteeling http to Z39.50 Z39.50 to http Trend

Aspects in standardisation n What do we want ? n High degree of interoperability n Low barrier implementation n High level of automation n How (besides reaching agreements)? n Extendibility: Do not reject a response with items that are not (yet) in the standard n Tolerance: Do not reject a response if items are missing if it is not fatal n Flexibility: Try to allow responses that are not requested n Do not rely on negotiation between http server (“take it or leave it”) and browser (“make the best of what it gets”) n Keep it simple Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Personal remark: As interaction between systems becomes more complex and is moving all the time, standardisation of request and response might require a more non-conventional approach.

OpenUrl (simplified) n OpenUrl=Base-url + query with standardised syntax Example: Base-url: Query: issn= &year=2000&vol=8&spage=123 n Usage: Dynamic and automatic generation of “just in case” links depending on “current” metadata and “user preferences”. n Link = request for service, search or object Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Personal link page n Metadata from anywhere link to any system of the user’s choice n Let the user set his own base-url (by means of a cookie) n Allow the user to set this base-url when presenting the metadata (“only one click away”) n The personal link page can analyse the query-part of the OpenUrl in the user’s browser: no server needed! Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Personal Link Page Query

Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Personal Link Page Response with javascript to allow setting the base url to personal link page.

Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Personal Link Page Next responses will show personal link page as default for openURL link. PLP Personal, context dependent, dynamically generated links Base-url points to plp

Record display with option to select personal link page Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Example of personal link page for articles Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Result obtained via PLP Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Example of personal link page for books Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

HTML-page to create plp Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

HTML page with Javascript to get issn from openurl and present a link Koninklijke Bibliotheek, Nationale bibliotheek van Nederland srch=unescape(location.search); srch=srch.substring(1,999); sarray=srch.split("&"); issn=""; for (i=0 ; i<sarray.length ; i++) { ind_key=sarray[i].split("="); if (ind_key[0] == "issn") issn=ind_key[1]; } function search() { if (issn== "") alert("No issn"); else location=" + issn } This is a very simple example of a personal link page. Click here to search on issn.

Additonal XML-metadata Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Query Response NO HITS Example : Response with terms that are most alike (fuzzyness) Fuzzy matching terms: Term 1 Term 2 Term 3 Term 4 Term 5

Additional responses n Related terms n Results of fuzzy matching n Index browse (z39.50 scan) n Short title list n Number of hits for each term n Etc. Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Additional data in XML Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Query to different targets Responses from different targets Fuzzy results Short title list No hits Index browse Fuzzy results Related terms Integration of the results allows the user to improve his query and retry a distributed search

Example of additional responses XML 0 abc bcd abc acc Koninklijke Bibliotheek, Nationale bibliotheek van Nederland For new tags that are not know to the client: Adapt XSL (and/or javascript) to display this item The user application may try to ask for this new tag (using the same name) in automatic generated urls. Example of requesting URL:

Electronic references, DOI and Crossref n Author submits article n Publisher resolves references n Publisher submits metadata to DOI-agent and receives DOI for referenced articles n Publication is issued n User requests publication n User clicks on DOI of reference (link to DOI- resolver) n DOI-resolver presents DOI metadata n User selects location from DOI metadata n User requests article from that location Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Remarks: 1.Not all references have a DOI 2.User may not have access to DOI-resolver 3.User may not have access to locations specified by the metadata from DOI-agent 4.The DOI identifies but does not localise objects

Retrieval of electronic references Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Query ? Article Reference 1 Reference 2 Reference 3 Search for referenced article Referenced article Personal link page resolved base-url (resolution)

Retrieval of electronic references Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Electronic references: what can libraries do? n Convert references via XML or HTML to OpenUrl’s n Maintain a local list of journals with the base-url of their locations n Forward the user’s query to new base-url for journals that are on other locations. Koninklijke Bibliotheek, Nationale bibliotheek van Nederland

Distributed query (Z39.50) Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Distributed query to the “whole world” user query

Central index (web search engines) Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Harvesting of the “whole world” user query

Selective query propagation Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Distributed search to selected targets user query subject y geographical ownership subject x

Selective query propagation (hybride solution) Koninklijke Bibliotheek, Nationale bibliotheek van Nederland target selection for subject x subject y geographical ownership subject x Distributed query to selected targets query to gateway or to selected targets directly Central index (OAI-protocol ?)

Multi target search Koninklijke Bibliotheek, Nationale bibliotheek van Nederland 1.Search for : dutchess art search* 2.Enter new search e.g. Rembrandt 3. Query will be send to all searchable targets

Metadata and digital objects n Separation of metadata and digital objects (different databases) n Metadata independent from digital objects (no hardcoded file names in bibliographic metadata) n Structure of digital objects not always known (e.g. subject to change e.g. due to preservation activities) n Digital objects can be anything (from single file to database of streaming objects) n Request is not always the whole digital object but a role: thumbnail, table of contents, title page etc. Koninklijke Bibliotheek, Nationale bibliotheek van Nederland Fields to be used in URL to request digital objects: 1.Identification of object (oid) 2.Role (standardised) Examples:

Conclusions and recommendations n Make your services OpenUrl-compatible n Focus on XML for the presented results and as transfer format n Implement the small piece of javascript to allow setting of the plp n Let’s come to agreements on extension of OpenUrl to allow for fast and “low barrier” implementation of extra services and searches. Koninklijke Bibliotheek, Nationale bibliotheek van Nederland