I watch the CD-ROM industry with considerable interest. Here at Vanderbilt University, we had one of the early CD-ROM networks in libraries. Since then, we have gone through many generations of CD-ROM networks. At CD's peak, we provided access to over 300 discs through our CD-ROM networks. Even though many of our formerly CD-ROM-based titles have shifted to Web access, we've yet to see a significant decline in the total number of CD-ROMs on the network. Large multi-disc products migrate to the Web, and several single-disc, lesser-used prodcts take their places.
Our current environment consists of three large CD-ROM servers, one with a 150-platter jukebox. Other than the one with the jukebox, all our CD-ROM servers are CD-ROM-less. We long since learned that transferring data from the CD-ROM discs onto large-scale magnetic discs offers significantly improved performance, supports higher numbers of simultaneous users, and is less expensive overall. Why buy towers of CD-ROM drives when the equivalent volume of magnetic storage costs a fraction?
Though we'll continue to maintain and upgrade these CD-ROM network servers as long as our libraries have titles that they want to provide to their users in this way, we expect the need to diminish over time. We also have a SilverPlatter ERL server and WebSPIRS clients that allow us to take the shared CD-ROM data in a client/server environment. More about that later. Fortunately, I have been able to delegate the day-to-day management of our CD-ROM efforts: Almost one full-time position in our Library Technology Team is dedicated to supporting CD-ROM-based products.
Besides watching the design and implementation of CD-ROM networks at Vanderbilt and other libraries, I have been following the industry as a writer and analyst. Since 1992 I have been covering CD-ROM networking technologies for DataPro Information Services (now part of GartnerGroup); I was a regular contributor to Mecklermedia's CD-ROM World before it ceased publication; and I have written White Papers for CD-ROM networking companies. It's been interesting to watch the realm of CD-ROM technologies evolve and transform over the past 12 years or so.
We now are witnessing an unmistakable migration away from CD-ROM-based products toward Web-based information resources accessed via the Internet. But does this mean the total demise of CD-ROM? Not necessarily. Read on to learn what place I believe that CD-ROM and DVD will have in the libraries of the next millennium.
The CD-ROM Format: Looking at Its Short Past
CD-ROM made a huge impact on libraries as one of the main technologies for providing access to databases of citations and abstracts. The term CD-ROM became almost synonymous with this category of products.
Libraries' first efforts at electronic information involved the creation of online catalogs. The ability for a library to provide information about its holdings of monographs, serials, and other materials represented a major advancement in using computer technology to provide access to information to library users. Through the OPAC, users could easily find a library's holdings—down to the title, copy, and issue.
The next step of advancement involved citation databases that provided access to journal articles, book chapters, and other resources. Some of the initial efforts in this area involved mounting citation databases into the same systems as the OPAC. These locally mounted databases involved a high burden of effort in the constant data loading and index generation they required.
As CD-ROM technology became more mature in the mid- to late 1980s, a large number of products emerged that were delivered on CD-ROM and that ran on personal computers. The PC would run a search-and-retrieval environment, pulling information off the CD-ROM loaded in the drive attached to the computer and reading the data directly off the CD-ROM disc. Unfortunately, each vendor took a somewhat different approach with its retrieval software, so users had to learn a different interface for each product. With this PC-based approach, only one person at a time could search each CD-ROM disc. Libraries would often purchase multiple copies of a CD-ROM product to offer access to multiple users at once. Multiple products, multiple computers, and multiple users all contributed to a complex and confusing environment.
CD-ROM networks soon emerged, allowing a library to purchase a single copy of a CD-ROM database and provide access to multiple computers on a network. The CD-ROM was loaded into a server on the network, and the library would pay an additional fee to the vendor for each simultaneous user, which was considerably less expensive than purchasing multiple copies. At the time, CD-ROM networks were the most efficient way to deliver multi-user access to citation and full-text information resources. Vendors such as Meridian Data, Online Computer Systems, and CBIS, Inc. specialized in providing CD-ROM networking solutions to libraries.
CD-ROM networks, however, were hardly the ideal approach. Libraries often purchased products from multiple vendors, forcing library users to deal with multiple search interfaces. The early CD-ROM networks were not technically elegant: The lack of standards and the various proprietary components involved proved difficult to implement and manage. The constant need to update the CD-ROM discs on the server, to install new products, and to deal with new versions of the search software periodically all contributed to the difficulty of managing a CD-ROM network. Another drawback was the difficulty of supporting different computing platforms and operating systems.
The CD-ROM network approach also created difficulties for the vendors of information products. The technical difficulties and incompatibilities of CD-ROM networking translated into a heavy support burden for the vendors. Distributing software and data for these products is a major undertaking. Constantly remastering discs and distributing updates to every single customer is quite a chore.
CD-ROM's Present: The Emergence of Client/Server and Web-Based Systems
Since the inception of the Web, there has been a gradual shift in the way that libraries provide information to their users. Most of the vendors of citation, abstract, and full-text information products have made the transition from delivering information on CD-ROM networks to delivering them on the Internet through the Web. You just can't miss this trend in the industry. Visit the exhibition hall of conferences such as ALA, Computers in Libraries, Internet World, or the National Online Meeting and you will see a plethora of Web-based products demonstrated and a dearth of CD-ROM-based applications. The information publishing community has fully embraced the Web as its preferred medium for distributing its products.
Web-based technologies solve many of the problems involved in the CD-ROM network approach for the information vendor, for the library, and for the end user. The basic model for delivering information on the Web involves a database stored on a centralized server, a search engine and indexes on the server for accessing the information, and Web-serving software programmed to communicate with the search engine. The user's Web browser communicates over an intranet or the Internet with the Web server to access the database. Figure 1 illustrates the classic model of a Web-based application.
Libraries find Web-based information much easier to support than CD-ROM networks. The convergence of systems around the Web allows libraries to build standard networks that support a large variety of systems and services. If a library develops a network that supports TCP/IP network protocols and provides a Web browser on each of its client computers, then it has the necessary infrastructure to support any Web-based product. Providing network access to Web-based information resources in a library is dead easy compared to the prior CD-ROM approach—no proprietary software or add-ins required. With all the search software operating from the central servers, the client network can be comparatively simple.
Web-based products typically are accessed via the Internet, with the database server located at the vendor's site. But this does not have to be the case. The database server can also be located within the library's own network. Several vendors, including SilverPlatter and Ovid, offer products allowing libraries to have a Web-based server locally rather than at the vendor's site.
Web-based technologies are not limited to citation, abstract, and full-text databases. Library automation systems with Web-based catalogs also follow this model. With a Web OPAC and a suite of Web-based citation and full-text databases, a library can offer a well-integrated suite of information resources. The degree of integration can be further enhanced through linking citation databases to full-text electronic resources and through an interface back to the library's online catalog to display current holdings of journals and periodicals. SilverPlatter's “SilverLinker” and “Link to Holdings” features are examples of products that offer this enhanced level of integration.
The move to Web-based products also makes progress toward solving the long-standing problem of requiring library users to master multiple search interfaces. Although there may be some differences in the Web interfaces from one vendor to another, the basic approach is much the same among them. Most users find it easy to operate the Web-based interfaces for the major information products to which the libraries subscribe.
Here Are Some Guideposts for the Next Millennium
The CD-ROM networking industry has changed significantly in the last couple of years. The products that were formerly promoted to create large-scale CD-ROM servers are in decline. The main approach that thrives in the marketplace now is the network attached CD-ROM/DVD miniserver. Examples of this are the Microtest DiscZerverVT and the Axis StorPoint CD E100. The CD-ROM networking industry has morphed into a niche within the low end of the current NAS (network attached storage) arena. Typical of this market evolution, the former library-oriented CD-ROM networking giant Meridian Data has been acquired by Quantum Corporation to diversify its storage products to include Meridian's NAS product, the Snap! Server.
For libraries that must implement some sort of CD-ROM network, the CD-ROM/DVD miniserver approach is the most practical one in today's market. Products such as the DiscZerver and the StorPoint CD offer easy setup and maintenance and include performance features such as disc caching that were formerly only found in the large-scale CD-ROM network servers.
If you have non-Web products that you need to continue to support on your in-library public access stations, you can use Web-launching applications to integrate them into such an environment. Through Web-launching, a user can click on a link on a Web page that then loads a Windows- or DOS-based product on the workstation. In many cases the Windows product will eventually be replaced by a Web-based version anyway. In today's environment, it makes sense to consider the Web as the standard approach.
CD-ROM stands as the preferred medium for distributing bloatware (ahem … I mean, software). The size of most applications has grown so large that distribution on diskettes is unthinkable, and downloading from the Internet could take days. As a read-only technology, CD-ROM offers greater safety from viruses than other media, and offers vendors more options for thwarting unauthorized use of licensed software.
CD-ROM is now an end-user medium. We already see a trend for CD-ROMs or DVDs to be included with books, and many titles are now published solely on CD-ROM instead of paper. Libraries increasingly have to deal with CD-ROMs in their circulation operations. I certainly expect that CD-ROMs and DVDs will gradually increase as a proportion of materials circulated in libraries.
DVD vs. CD-ROM:Which Format Wins Now?
DVD will likely supplant CD-ROM over time, but the transition will take several more years. It is just now getting to the point where you should be thinking about DVD drives instead of CD-ROM drives as you buy new computers for your library. Most computer hardware manufacturers offer DVD as a fairly minimal added-cost option now. In a year or two, DVD drives should be standard. There is no particular reason to jump ahead of the curve though, unless your library already has a significant number of titles now that are available only on DVD and not CD-ROM.
Focus on Content!
The point that I want to stress the most is that CD-ROM and DVD are just storage media. Paper or plastic? Optical or magnetic? CD or DVD? Don't focus on the format, but rather on the content of information products, and on the overall architecture of the library's information environment. Buy the titles that offer the most valuable information content and the most exciting delivery and presentation. Vendors are not going to offer products on media that are not accessible by their clientele. We have to assume that the computer industry will define and develop appropriate storage technologies. Libraries just need to pay attention to the general trends in the industry and develop data storage and information infrastructures consistent with the world at large, but each needs to do so in a way that is optimized for its specialized needs.
Marshall Breeding is the technology analyst for the Jean & Alexander Heard Library at Vanderbilt University in Nashville, Tennessee. He has edited or authored several books on library technology and Internet-related technologies, and has written dozens of articles on these topics. His e-mail address is firstname.lastname@example.org. His Web page is at staffweb.library.vanderbilt.edu/breeding.