Catálogo de publicaciones - libros

User interfaces for digital library systems must support a wide range of user activities. They include search, browsing, and curation, but perhaps the most important is actual reading of the items in the library. Support for reading, however, is usually relegated to applications which are only loosely integrated with the digital library system. One reason for this is the absence of toolkit widget support for the activity of reading. Most user interface toolkits instead provide support for either text editing or text presentation, making it difficult to write applications which support reading well. In this paper we describe the origins, design, and implementation of a new Java Swing toolkit widget called ReadUp , which provides support for reading page images in a digital library application, and discuss briefly how it is being used.

Last year at the ECDL 2004 conference, we reported some initial progress and experiences developing DSpace as an open source community-driven project [8], particularly as seen from an institutional manager’s viewpoint. We also described some challenges and issues. This paper describes the progress in addressing some of those issues, and developments in the DSpace open source community. We go into detail about the processes and infrastructure we have developed around the DSpace code base, in the hope that this will be useful to other projects and organisations exploring the possibilities of becoming involved in or transitioning to open source development of digital library software. Some new challenges the DSpace community faces, particularly in the area of addressing required system architecture changes, are introduced. We also describe some exciting new possibilities that open source development brings to our community.

This paper introduces the write-once/read-many XMLtape/ARC storage approach for Digital Objects and their constituent datastreams. The approach combines two interconnected file-based storage mechanisms that are made accessible in a protocol-based manner. First, XML-based representations of multiple Digital Objects are concatenated into a single file named an XMLtape. An XMLtape is a valid XML file; its format definition is independent of the choice of the XML-based complex object format by which Digital Objects are represented. The creation of indexes for both the identifier and the creation datetime of the XML-based representation of the Digital Objects facilitates OAI-PMH-based access to Digital Objects stored in an XMLtape. Second, ARC files, as introduced by the Internet Archive, are used to contain the constituent datastreams of the Digital Objects in a concatenated manner. An index for the identifier of the datastream facilitates OpenURL-based access to an ARC file. The interconnection between XMLtapes and ARC files is provided by conveying the identifiers of ARC files associated with an XMLtape as administrative information in the XMLtape, and by including OpenURL references to constituent datastreams of a Digital Object in the XML-based representation of that Digital Object.

The Multivalent Document Model offers a practical, proven, no-compromises architecture for preserving digital documents of potentially any data format. We have implemented from scratch such complex and currently important formats as PDF and HTML, as well as older formats including scanned paper, UNIX manual pages, TeX DVI, and Apple II AppleWorks word processing. The architecture, stable since its definition in 1997, extends easily to additional document formats, defines a cross-format document tree data structure that fully captures semantics and layout, supports full expression of a format’s often idiosyncratic concepts and behavior, enables sharing of functionality across formats thus reducing implementation effort, can introduce new functionality such as hyperlinks and annotation to older formats that cannot express them, and provides a single interface (API) across all formats. Multivalent contrasts sharply with emulation and conversion, and advances Lorie’s Universal Virtual Computer with high-level architecture and extensive implementation.

The results of an ongoing interview study with custodians of historic photograph collections are reported. In particular the success or otherwise of recent digitisation projects is addressed, as well as the extent to which these projects have affected the long term management of the collections. We examine the effects of digitisation on the primary sources, their digitised surrogates and the relationship between the two in terms of selection, authenticity and representation. In most cases we have observed that the emphasis placed by the funding bodies on ‘accessibility’ of tangible numbers of resources is detrimental to these three other issues. However, we report in detail on one case study of a local history library where its digitisation work is embedded in core library activity and seen as successful and positive. We conclude by suggesting that their deliberate eschewing of short term project funding is a determining factor in their success.

The OAI protocol facilitates the aggregation of large numbers of heterogeneous metadata records. In order to make harvested records useable in the context of an OAI service provider, the records typically must be filtered, analyzed and transformed. The CIC metadata portal harvests 450,000 records from 18 repositories at 9 U.S. Midwestern universities. The process implemented for transforming metadata records for this project supports multiple workflows and end-user interfaces. The design of the metadata transformation process required trade-offs between aggregation homogeneity and utility for purpose and pragmatic constraints such as feasibility, human resources, and processing time.

The Alexandria Digital Library (ADL) project has been working on automating the processes of building ADL collections and gathering the collection statistics on which ADL’s discovery system is based. As part of this effort, we have created a language and supporting programmatic framework for expressing mappings from XML metadata schemas to the required ADL metadata views. This language, based on the Python scripting language, is largely declarative in nature, corresponding to the fact that mappings can be largely—though not entirely—specified by crosswalk-type specifications. At the same time, the language allows mappings to be specified procedurally, which we argue is necessary to deal effectively with the realities of poor quality, highly variable, and incomplete metadata. An additional key feature of the language is the ability to derive new mappings from existing mappings, thereby making it easy to adapt generic mappings to the idiosyncrasies of particular metadata providers. We evaluate this language on three metadata standards (ADN, FGDC, and MARC) and three corresponding collections of metadata. We also note limitations, future research directions, and generalizations of this work.

The National Digital Data Archive (NDDA) is an ongoing initiative of the Hungarian government that makes Hungary’s national cultural assets available in digital form. The NDDA features a decentralized OAI-based network of archives and service providers facilitating discovery and access to digitized objects. Authors’ participation in the project is described including the implementation of an NDDA service provider. This service provider is connected with an RDF-based metadata schema registry enabling the service to automatically adapt to the metadata schemas defined within the NDDA.

The challenge of finding appropriate learning objects is one of the bottlenecks for end users in Learning Object Repositories (LORs). This paper investigates usability problems of search tools for learning objects. We present findings and recommendations of an iterative usability study conducted to examine the usability of a search tool used to find learning objects in ARIADNE Knowledge Pool System [1]. Findings and recommendations of this study are generalized to other similar search tools.

The personalized project space is an important feature in G-Portal that supports individual and group learning activities. Within such a space, its owner can create, delete, and organize metadata referencing learning objects on the Web. Browsing and querying are among the functions provided to access the metadata. In addition, new schemas can be added to accommodate metadata of diverse attribute sets. Users can also easily share metadata across different projects using a “copy-and-paste” approach. Finally, a viewer to support offline viewing of personalized project content is also provided.