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Ndltd Dissertations

  • Atkins, A., Fox, E.A., France, R.K., & Suleman, H. (Eds.). (2001).ETD-ms: An Interoperability Metadata Standard for Electronic Theses and Dissertations — version 1.00. [Online] Available: Scholar

  • Borgman, C.L. (1999). What are digital libraries? Competing visions.Information Processing and Management, 35, 227–243.CrossRefGoogle Scholar

  • Das Neves, F.A., & Fox, E.A. (2000). A study of user behavior in an immersive virtual environment for digital libraries.Proceedings of the 5th Conference (pp. 103–111). New York: ACM Press.Google Scholar

  • Fox, E.A. (1999). The 5S Framework for Digital Libraries and Two Case Studies: NDLTD and CSTC.Proceedings of the 11th International Conference on New Information Technology (pp. 115–126). W. Newton, MA: MicroUse Information.Google Scholar

  • Fox, E A., France, R.K., Sahle, E., Daoud, A.M., & Cline, B.E. (1993). Development of a Modern OPAC: From REVTOLC to MARIAN,Proceedings of the 16th International ACM SIGIR Conference (pp. 248–259). New York: ACM Press.Google Scholar

  • Fox, E.A., & Marchionini. G. (1998). Toward a worldwide digital library.Communications of the ACM, 41(4), 29–32.CrossRefGoogle Scholar

  • Fuhr, N., Hansen, P., Mabe, M., Micsik, A., & Solvberg, I. (2001). Digital Libraries: A Generic Classification and Evaluation Scheme.Proceedings of the 5th European Conference on Research and Advanced Technology for Digital Libraries (ECDL2001).Google Scholar

  • Giles, C.L., Bollacker, K.D., & Lawrence, S. (1998).Proceedings of the 3rd ACM Conference on Digital Libraries, (pp. 89–98). New York: ACM Press.CrossRefGoogle Scholar

  • Gonçalves, M.A., Fox, E.A., Watson, L.T., & Kipp, N.A. (2001a). Streams, Structures, Spaces, Scenarios, Societies (5S): A Formal Model for Digital Libraries.Technical Report TR-01-12. Virginia Tech Department of Computer Science.Google Scholar

  • Gonçalves, M.A., France, R.K., & Fox, E.A. (2001b). MARIAN: Flexible Interoperability for Federated Digital Libraries.Proceedings of the 5th European Conference on Research and Advanced Technology for Digital Libraries (ECDL2001).Google Scholar

  • Kengeri, R., Seals, C.D., Harley, H.D., Reddy, H.P., & Fox, E.A. (1999). Usability study of digital libraries: ACM, IEEE-CS, NCSTRL, NDLTD.International Journal of Digital Libraries, 2(2), 157–169.CrossRefGoogle Scholar

  • Lagoze, C., & Van de Sompel, H. (2001). The Open Archives Initiative: Building a Low-Barrier Interoperability Framework.Proceedings of the First ACM/IEEE-CS Joint Conference on Digital Libraries (pp. 54–62). New York: ACM Press.CrossRefGoogle Scholar

  • Marchionini, G., & Maurer, H. (1995). The Roles of Digital Libraries in Teaching and Learning.Communications of the ACM, 38(4), 67–75.CrossRefGoogle Scholar

  • McMillan, G. (2001a, June) “Do ETDs Deter Publishers?”College and Research Libraries News, 62(6), 620–621.Google Scholar

  • McMillan, G. (2001b) “What to Expect from ETDs: Library Issues and Responsibilities.” 4th International Conference on ETDs, Caltech, March 24, 2001. [Online] Available: Scholar

  • Powell, J., & Fox, E.A. (1998, September). Multilingual Federated Searching Across Heterogeneous Collections.D-Lib Magazine, [Online] Available: Scholar

  • Rao, R, & Pedersen, J. O., Hearst, M. A., Mackinlay, J. D., Card, S. K., Masinter, L., Halvorsen, P., & Robertson, G. C. (1995).Communications of the ACM, 38(4), 29–39.CrossRefGoogle Scholar

  • Reddy, R., & Wladawsky-Berger, I. (Eds.). (2001).Digital libraries: Universal access to human knowledge — A report to the president. President Information Technology Advisory Committee (PITAC), Panel on Digital Libraries.Google Scholar

  • Saracevic, T., & Covi, L., (2000). Challenges for digital library evaluation.Proceedings ASIS, 37, 341–350.Google Scholar

  • Urs, S.R., & Raghavan, K.S. (2001). Vidyanidhi: Indian digital library of electronic theses.Communications of the ACM, 44(5), 88–89.CrossRefGoogle Scholar

  • Table 4. Access by Non-US Sites


    Multimedia Use in ETDs

    One of the main objectives of NDLTD is to promote student creativity through the use of diverse types of multimedia content in ETDs, while making students comfortable with the use of this technology to exploit richer modes of self-expression.

    Table 5 indicates how much of this objective has been achieved in the VT-ETD collection, with a breakdown of the 8,056 multimedia files contained in a selection of 2,180 available ETDs. This illustrates both that authors are beginning to shift towards non-textual media and that some are moving away from the early single-file paradigm of digitization.

    File type



    Still imageBMP, DXF, GIF, JPG, TIFF


    VideoAVI, MOV, MPG, QT


    AudioAIFF, WAV




    OtherMacromedia, SGML, XML


    Table 5. Multimedia use in VT-ETD collection


    Worldwide Release

    In terms of copyright, a significant issue is whether to allow the electronic document to be viewed worldwide, on campus only, or not at all. The “mixed” case, which is a unique capability of electronic documents, occurs when some portions (e.g., particular chapters or multimedia files) have restricted access while others are more widely available. The majority of Virginia Tech students allow their documents to be viewable worldwide (see Figure 1) - but some initially choose not to grant worldwide access in order to protect their publication rights. To address this concern, there are ongoing discussions with publishers to help them understand the goals and benefits of NDLTD [NDLTD, 1999]. We are pleased to see a change in attitude by some publishers over the course of the project. The American Chemical Society developed a policy more favorable to NDLTD as a result of lengthy discussions and the American Physics Society has been receptive to issues concerning the Open Archives Initiative and NDLTD.


    Figure 1. Student and committee choice for ETD availability from Virginia Tech
    (2668 ETDs as of July 17, 2000).


    Standards Activity

    In order to support many of the current and future research and service-related activities, work has begun to define standards that will enable more consistent exchange of information in an interoperable environment. Among the first of these projects is ETDMS - the Electronic Thesis and Dissertation Metadata Standard - and a related project for name authority control.

    Electronic Thesis and Dissertation Metadata Standard (ETDMS)

    ETDMS was developed in conjunction with the NDLTD, and has been refined over the course of the last year. The initial goal was to develop a single standard XML DTD for encoding the full text of an ETD. Among other things, an ETD encoded in XML could include rich metadata about the author and work that could easily be extracted for use in union databases and the like. During initial discussions it became clear that the methods used by different institutions to prepare and deal with theses and dissertations would make it all but impossible to agree on a single DTD for encoding the full text of an ETD. Many institutions were unwilling or unprepared to use XML to encode ETDs at all.

    Thus, instead of an XML DTD for encoding the full text of an ETD, ETDMS emerged as a flexible set of guidelines for encoding and sharing very basic metadata regarding ETDs among institutions. Separate work continues in parallel on a suite of DTDs, building on a common framework, for full ETDs.

    ETDMS is based on the Dublin Core Element Set [DCMI, 1999], but includes an additional element specific to metadata regarding theses and dissertations. Despite its name, ETDMS is designed to deal with metadata associated with both paper and electronic theses and dissertations. It also is designed to handle metadata in many languages, including metadata regarding a single work that has been recorded in different languages. The ETDMS standard [Atkins, et al., 2001] provides detailed guidelines on mapping information about an ETD to metadata elements.

    ETDMS already is supported as an output format for the Open Archives interface to the Virginia Tech ETD collection. ETDMS will be accepted as an input format for the union catalog currently being developed in conjunction with VTLS [VTLS, 2001]. NDLTD strongly encourages use of ETDMS.

    Authority Linking

    Each reference to an individual or institution in an ETDMS field should contain a string representing the name of the individual or institution as it appears in the work. In addition, these references also may contain a URI that points to an authoritative record for that individual or institution. Associating authority control with NDLTD seems particularly appropriate since universities know a great deal about those to whom they award degrees and since a thesis or dissertation often is the first significant publication of a student.

    The “NDLTD: Authority Linking Proposal” [Young, 2001] identifies several goals for a Linked Authority File (LAF) system to support this requirement:

    • LAF records should be freely created and shared among participants. While a central authority database is an option, the LAF design expects the database to be distributed to share cost. Individual participants or groups should be able to host a copy of the LAF database and share changes they make to local copies of LAF records with other hosts using the Open Archives Initiative (OAI) protocol [Lagoze and Van de Sompel, 2001]. The mechanism for keeping records in sync is described in the proposal.
    • The URIs should be meaningful and useful to anyone outside NDLTD’s domain. A benefit of using the OAI protocol is that individual LAF records will be accessible via an OAI GetRecord request (discussed in the second part of this article).
    • The URIs should be persistent and current. This raises a number of challenges, such as duplicate resolution. By using PURLs [OCLC, 2001] in ETDMS records, the underlying OAI GetRecord URLs can be rearranged without affecting the ETDMS records that rely on them.
    • The model should be scalable and applicable beyond NDLTD. The LAF model was designed to work entirely with open standards and open-source software.

    The LAF design has other advantages over alternatives such as the Library of Congress Name Authority Database [Library of Congress, 2001]. Only the level of participation among decentralized participants limits the coverage of the collection. Because the records are based on XML, the content of LAF records can be as broad or narrow as needed. Finally, because they are distributed using the OAI protocol, multiple metadata formats can be supported.

    Future of NDLTD

    The statistics presented illustrate that the production and archiving of electronic theses and dissertations is fast becoming an accepted part of the normal operation of universities in the new electronic age. NDLTD is dedicated to supporting this trend with tools, standards, and services that empower individual institutions to set up and maintain their own collections of ETDs. At the same time NDLTD promotes the use of these ETDs through institutional websites as well as portal-type websites that aggregate the individual sites and create seamless views of the NDLTD collection.

    Ongoing research and service-provision projects are addressing the problems of how to merge together the currently distributed and somewhat isolated collections hosted at each member institution. The second part of this article discusses some of these projects in detail, including development of the Union Catalog Portal based on VTLS’s Virtua system and the myriad of research efforts investigating how to provide better services to researchers with specific information-seeking needs and behaviors.


    Atkins, Anthony, Edward A. Fox, Robert France and Hussein Suleman (editors). 2001. ETD-ms: an Interoperability Metadata Standard for Electronic Theses and Dissertations -- version 1.00. Available from <>.

    DCMI. 1999. Dublin Core Metadata Element Set, Version 1.1: Reference Description. Available from <>.

    Fox, Edward A. 2000. Core Research for the Networked University Digital Library (NUDL), NSF IIS-9986089 (SGER), 5/15/2000 - 3/1/2002. Project director, E. Fox.

    Fox, Edward A., John L. Eaton, Gail McMillan, Neill A. Kipp, Laura Weiss, Emilio Arce, and Scott Guyer. 1996. National Digital Library of Theses and Dissertations: A Scalable and Sustainable Approach to Unlock University Resources, D-Lib Magazine, September 1996. Available at <>.

    Fox, Edward A., Brian DeVane, John L. Eaton, Neill A. Kipp, Paul Mather, Tim McGonigle, Gail McMillan, and William Schweiker. 1997. Networked Digital Library of Theses and Dissertations: An International Effort Unlocking University Resources, D-Lib Magazine, September 1997. Available at <>.

    Fox, Edward A., Royca Zia, and Eberhard Hilf. 2000. Open Archives: Distributed services for physicists and graduate students (OAD), NSF IIS-0086227, 9/1/2000-8/31/2003. Project director, E. Fox (w. Royce Zia, Physics, VT, and E. Hilf, U. Oldenburg, PI on matching German DFG project).

    Fox, Edward A., J. Alfredo Sánchez, and David Garza-Salazar. 2001. High Performance Interoperable Digital Libraries in the Open Archives Initiative, NSF IIS-0080748, 3/1/2001-2/28/2003. Project director, E. Fox (with co-PIs J.Alfredo Sánchez, Universidad de las Américas-Puebla --- UDLA, and David Garza-Salazar, Monterrey Technology Institute --- ITESM, both funded by CONACyT in Mexico).

    Kipp, Neill, Edward A. Fox, Gail McMillan, and John L. Eaton. 1999. FIPSE Final Report, 11/30/99. Available from <> (PDF version) and <> (MS-Word version).

    Lagoze, Carl and Herbert Van de Sompel. 2001. The Open Archives Initiative Protocol for Metadata Harvesting. Open Archives Initiative. January 2001. Available from <>.

    Library of Congress. 2001. Program for Cooperative Cataloguing Name Authority Component Home Page. Available from <>.

    NDLTD. 1999. Publishers and the NDLTD. NDLTD, July 1999. Available from <>.

    OCLC. 2001. Persistent URL Home Page. Dublin, OH: OCLC Online Computer Library Center. Available from <>.

    Powell, James and Edward A. Fox. 1998. Multilingual Federated Searching Across Heterogeneous Collections. D-Lib Magazine, September 1998. Available at <>.

    VTLS. 2001. Virtua ILS. Available from <>.

    Young, Jeffrey A. 2001. NDLTD: Authority Linking Proposal. Dublin, OH: OCLC Online Computer Library Center. Available from <>.

    Copyright 2001 Hussein Suleman, Anthony Atkins, Marcos A. Gonçalves, Robert K. France, Edward A. Fox, Vinod Chachra, Murray Crowder, and Jeff Young