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Special: CD-ROMs

By Kristin E. Nelson, Donna Milici, and Patricia Renfro

Part I. The state of the art

Compact discs, those small, shiny discs that have taken over music stores, are now infiltrating the shelves of software vendors and bookstores. Audio CDs gained popularity because of their superior sound, small size, and durability; computer CDs are becoming popular for the same reasons, in addition to their capability for storing large amounts of data and integrating different media formats.

Until recently, the 10-year-old CD-ROM (compact disc-read only memory) technology, originally introduced as an alternative to floppy disks and magnetic tape storage media, suffered from the "chicken and egg" syndrome: With few software titles on discs, consumers had little incentive to buy CD drives, and without an installed base of CD players, software publishers had little incentive to produce titles on compact disc. The current proliferation of CD-ROM titles and players indicates not only that this cycle has broken but that CD technology is a hot trend in desktop computing.

CD-ROMs meet the current demand for a high-capacity, low-cost storage medium that can handle various types of information: text, graphics, sound, and video. A single CD-ROM can contain over 600 Mbytes of data -- more than a typical hard drive, 800 double-sided, double-density diskettes, or 200,000 printed pages. In addition, CD-ROM is a durable medium that can be mass produced and shipped at low cost. Nevertheless, the technology does have two important drawbacks: The players are much slower than hard drives (generally about 10 times slower) and the discs cannot be used to store data that changes.

Uses of CD-ROM

While all compact discs may look alike, they serve many different purposes.

Distribution. Compact discs are widely used to replace traditional distribution methods:

• Bulky volumes of printed information, such as government resources or system documentation.
• Large sets of data on magnetic tape, which a system administrator has to transfer to a local mainframe.
• Software packages on floppy disks. CD-ROM distribution minimizes the problems of file corruption and missing program diskettes common to floppy disks.

The usefulness of CD technology as a distribution medium has led some vendors to use CDs to distribute product samplers, allowing consumers to try a number of commercial products without a commitment to purchase. A single phone call and credit-card charge unlocks the full capabilities of some, or all, of the products on the discs.

Reference. CD-ROM has become a popular reference resource because users can quickly search a large amount of material stored on a single CD. Many university libraries have installed CD drives to access a variety of reference material available via CD-ROM

Education. The multimedia capabilities of CD-ROM technology make it a new vehicle for educational uses. To see some of the possibilities that CD-ROMs present, consider replacing traditional resources for learning a foreign language -- printed texts, audio tapes, a pocket dictionary, and foreign films -- with a single CD that could display the text, provide audio pronunciation, show the definition of a word, and play film footage of the foreign location described in the text. An individual could search for information about a specific topic, which would be immediately available on the computer monitor. Educational resources on CDs are widely available for grades K-12 and more titles are becoming available for higher education.

Music. While most people are aware that CDs may contain the soundtrack for a favorite musical, they may not know that with the proper software and hardware, these digital audio CDs can also be played on a computer.

Photos. Kodak's new PhotoCD discs can store up to 100 35-mm photographs, which can be used for on-screen viewing or can be integrated into electronic documents or presentations.

Entertainment. Aside from any entertainment value in the above categories, certain CDs are created purely for fun. Computer games take a new twist with the audio and video capabilities of CD-ROM.

Titles in each of the above categories are currently available on CD-ROM, and with the proper hardware and software, they can open a new chapter in how you use your desktop computer.

If you are buying...

There is no shortage of CD-ROM drives on the market today. If you want to add CD capability to your Macintosh or IBM PC/compatible, consider the following factors.

Transfer rate. The time to bring information from the CD to the computer's memory is most important for applications needing a steady stream of data, such as video and multimedia applications. Current CD drives are known as double-speed drives because the transfer speed of 300 Kbps (kilobytes per second) is double the 150 Kbps rate of earlier drives and audio CD players. While the newest drives, triple-speed (450 Kbps) or quad-speed (600 Kbps), may provide some speed benefit for reading large image or data files and may provide slightly smoother video, a double-speed drive is sufficient for most CDs currently available. CD drives also come with a buffer or cache (generally 64 Kbytes to 256 Kbytes for double-speed drives) to help maintain a steady flow of data to the computer's processor. Look for drives with a minimum transfer rate of 300 Kbps with at least a 64 Kbyte buffer.

Access time. The time it takes to locate a piece of information on the CD-ROM is important for applications that primarily search the disc for information, such as database applications. Look for drives with access times less than 300 milliseconds (ms).

XA ready. A drive that is CD-ROM/XA (eXtended Architecture) ready can read discs written in the XA format, which is a standard for storing compressed audio and video information on the disc. Select a drive that is CD-ROM/XA ready.

PhotoCD capability. Drives labeled with the Kodak PhotoCD logo are capable of reading images from a PhotoCD disc. While most compact discs are factory pressed for mass production, you can create a custom PhotoCD by taking your own photos to a local photo shop.

Multi-session capability. A multi-session drive can read information written to a CD at different times, but a single-session drive can only read what was written to the disc the first time it had information stored on it. For example, if two rolls of film are placed on a PhotoCD at two different times, a single-session drive can read only the first set of images while the multi-session drive can read all the images. Look for a drive with multi-session capability.

MPC compatibility. The Multimedia PC, MPC, or MPC2 label on a CD drive or disc indicates compatibility with standards set by the Multimedia PC Marketing Council for running multimedia on an IBM PC/compatible. A disc labeled MPC2 requires a minimum of a 25 MHz, 486SX CPU with VGA graphics; 160 Mbyte hard drive; 4 Mbytes RAM; 16-bit sound board; Windows 3.1; and a CD-ROM/XA, multi-session drive with 300 Kbps transfer rate and 400 ms access time. A disc labeled MPC has lower minimum requirements, including a CD-ROM drive with 150 Kbps transfer rate and 1,000 ms access time.

When shopping for a CD-ROM disc, check the label for MPC, DOS, Windows, or Macintosh compatibility. Discs labeled for DOS without the MPC label do not require Microsoft Windows. Some discs are identified as working with both Macintosh and IBM PC/compatible computers.

Connections. IBM PC/compatible microcomputers generally require that a card be added to the machine to use a CD-ROM drive. The CD drive may plug into the available CD-ROM port on a sound card, if purchased in a multimedia bundle; or the SCSI (small computer system interface) port of an internal SCSI adapter card; or an external parallel-to-SCSI adapter. For Macintosh computers, a CD drive connects to the built-in Macintosh SCSI port. Before purchasing any CD drive, check with its manufacturer to identify what hardware and software is needed to make it work with your computer.

If you're considering purchasing a CD-ROM drive to use with today's CD-ROM discs, look for a double-speed, multi-session, CD-ROM/XA-capable drive with the proper connections for your Macintosh or IBM PC/compatible. If you are purchasing a new computer, consider adding an internal CD-ROM drive as a purchase option.

Part II. Educational CDs

Recently we have seen an increased number of educational CD-ROM offerings in catalogs and trade journals, and by educational software vendors. Are they the long-awaited answer to the "computer-aided instruction" craze of a decade ago or simply a fleeting fancy? Is CD- ROM a medium with real potential for enhancing the learning experience and, if so, at what level (K-12 or higher education)? Are people using this technology? What are the benefits, obstacles, and projections for the future?

Uses at Penn

Let's start by taking a look at how CD-ROM technology is being used in instruction and research in our own academic environment. One example of instructional use can be seen in the School of Engineering and Applied Science, where a materials science textbook, The Bicycle and the Walkman, is being reengineered in hypertext format on CD-ROM. Conceived and developed by Professors Charles J. McMahon, Jr., and Charles D. Graham, Jr., this project was initially viewed as a regular printed textbook that used an innovative case study approach to teach an introductory materials science course. In conjunction with the print version of the text, the authors recently created a multimedia module that treats the subject of polymeric materials. The video component of the module allows the authors to teach molecular structures, for example, in a multi-dimensional fashion, a capability that print materials cannot provide. In the book's hypertext incarnation, multimedia technology is used to enhance understanding of difficult concepts in materials science that can be visualized over time and in three dimensions. This is accomplished through the addition of graphics, animations, and video clips. In addition, standard navigation controls are available, along with random access to sections, help, glossary entries, and review questions.

An example of CD-ROM use in humanities research can be seen in the School of Arts and Sciences. Professor Robert Kraft, his colleagues, and students make regular use of data on CD-ROM in the study of ancient texts, particularly Greek and Latin. This type of research, in which large collections of materials are reviewed and studied, often in a non-linear fashion, can be enhanced by the use of a flexible storage medium. The primary advantage offered by CD-ROM is the ability to search large databases quickly and conveniently. Dr. Kraft would also like to expand his use of CD-ROM materials in the study of Christian texts in Latin and Jewish texts in Hebrew and Aramaic, contingent upon the ability to get the CD-ROMs to run properly. He'd also like to make use of maps on CD-ROM, but pursuing this will take time.

CD-ROM use among students

Many Macintosh computers that students purchased from the Computer Connection during the Fall 1993 Truckload Sale had CD-ROM drives as part of their system configuration. An informal poll of students through the upenn.talk newsgroup reveals that a popular use of these drives is for listening to audio CDs. Some of the more adventuresome are also exploring multimedia capabilities, by working with CDs containing sounds, graphics, clip art, and HyperCard stacks. Still others are investigating the purchase of CD-ROM games or reference materials, such as encyclopedias.

One interesting experiment underway in the student residences may provide an opportunity for students to explore the potential of CD-ROM offerings. Christopher Dennis, Director of Academics Programs in Residence, is setting up a CD-ROM pilot program in DuBois College House this semester. After receiving a request from the House Council to update library resources, Dennis decided to replace an old encyclopedia with the Grolier Multimedia Encyclopedia, which offers interactive access to information enhanced by video and sound. Dr. Dennis is also exploring the possibility of adding other CD-ROM resource materials to the house collection and creating similar libraries in other residences.

Hurdles

What is the future of CD-ROM technology in higher education? Although we have seen significant improvement in speed, navigation tools, and exploitation of video and sound in CD-ROM resources over the past several years, numerous barriers have to be removed before we can expect to see a true democratization of this technology in academia. Foremost among the hurdles encountered by faculty and students here at Penn are:

• difficulty of assessing the quality of commercial offerings: A brief descriptor in a catalog is insufficient for gauging the effectiveness of a CD-ROM resource.
• cost: Most of today's commercial offerings are still too expensive for individual student purchases, and the industry as a whole needs to come up with effective site license and network access alternatives.
• NIHS (not-invented-here syndrome): Commercial offerings, as well as many resources developed at other educational institutions, are "read-only"; many faculty members would prefer to be able to easily modify CD-ROM resources for their environments.
• time and money: Many innovative ideas remain undeveloped because there is neither time nor money to invest in the creation of useful CD-ROM resources for instruction or research; increased support from within the institutions, from publishers, and from funding foundations is necessary to support development.
• ownership issues: Issues regarding copyrights, patents, and intellectual property rights often result in limitations on use and dissemination of CD-ROM resources; these issues need to be discussed and resolved by all parties involved, as current laws and guidelines don't adequately address them.
• accessibility: Individual desktop machines, as well as those in public access labs, must be suitably equipped for using CD-ROM technology effectively.
• slow or inadequate performance: Many people still find the search and retrieval tools to be sub-optimal; others find that the effort required to get a system configured and optimized for running CD-ROMs is unacceptable.
• insufficient value added: There are many examples of flashy technology being used solely for effect, with little value added; attention must be paid to what the new technology provides and how it can enhance traditional media offerings.

Potential

Although most of the "educational" uses of CD-ROMs are currently for pre-school and K-12 students, there have been some promising developments for the higher education audience. Exciting examples include:

• Perseus 1.0, Interactive Sources and Studies on Ancient Greece, an interactive resource for the study of ancient Greece; one resource recently published by Yale University Press on CD-ROM.
• Who Built America?, containing historic documents, recordings, videos, and over 1,000 pictures; one of many books on CD-ROM published by Voyager.
• The Crucible, incorporating audio, video clips, interviews, and scholarly commentary to enhance the text; one of several interactive works distributed on CD-ROM by Penguin USA.

If the hurdles outlined above can be surmounted, those involved in developing CD-ROM resources believe there is a growing market for this technology which is likely to get an even stronger boost as more textbook publishers get involved. Robert Kraft predicts that we'll see more CD-ROM products for instructional use, but that they will probably be slow in coming since there is no centralized support (such as publishers or generous funders) to facilitate progress. He outlined the process we might expect to see as follows: Networked experimentation will lead to CD-ROM capture and development, experimentally and then by the less timid publishers. "There is a great interest in hypertexting, and especially in the use of images, but where the technology permits, energies are going into network access first, and it may be that CD-ROM access will follow, but that depends on lots of factors, the most important of which are time and money, in that order."

As a new generation of computer-literate students exposed to multi-sensorial stimuli enters our institutions, we need to find new ways to create conducive learning environments for them. The interactive, hypertextual opportunities provided by CD-ROM technology may offer one answer.

Part III. CD-ROMs in Penn Libraries

Patricia D'Alonzo, a student in the College majoring in economics, is getting a taste for what historical research involves in Donna Rilling's history seminar. The current assignment is to write a paper drawing on primary resource material -- Ben Franklin's own Pennsylvania Gazette. Using Van Pelt's CD-ROM of the newspaper, Patricia looks for material on attitudes to the theater in the first half of the eighteenth century. The disc allows her to track down a list of references and then read the full text of the paper on screen. But what makes the Gazette real to her is the capability (at a single keystroke) to switch from searchable text to a bit-mapped image of the original paper complete with advertisements and announcements.

MBA student Steve Kitadei recently used the Lippincott Library's Worldscope database to research a paper comparing the strategic alliances made by Sony and Corning. He found the combination of financial data in annual reports and citations to articles in the Wall Street Journal and Financial Times right on target. Steve has only one complaint about the Worldscope CD, and that is that he can't access it from home.

Patricia and Steve are two of the thousands of Penn students and faculty who use over 120 CD products available throughout the Penn Libraries. Inexpensive to produce, and easy to deliver and market, compact discs have become an increasingly popular medium for vendors of data. Many of the Library's CDs are key bibliographic databases, but a significant number also provide users with complete text or numeric data. Among the many electronic resources in the Lippincott Library are CD-ROM images of annual reports for over 15,000 U.S. and foreign companies and a 450-disc collection of index and page images for over 400 current business and management journals, which eliminates the need to track journal volumes down in the Library's stacks. In Van Pelt, users of the 1990 Census of Population and Housing CDs have access to more data, in more detail, for more geographic areas, than for any previous census. Data that was distributed on magnetic tape or on microfiche for the 1980 census is now easily accessible on disc. A set of 10 discs cover city block statistics for the entire country, and the 46 Tiger/Line Census discs supply data on 85 percent of the street addresses in the United States.

Numerous other powerful new databases can be found in libraries across campus. In the Annenberg Library, students can use the Broadcast News CD to review transcripts of news and current affairs programs on ABC, CNN, NPR, and PBS; or they can search Ethnic Newswatch, a full-text database of English and Spanish language newspapers from ethnic and minority presses in the United States. At the Biomedical Library, the Entrez CD allows researchers to move from journal citations to protein or nucleotide sequence information. Also on CD at the Biomedical Library is MDX Health Digest, a consumer health database listing references in health and general-interest magazines, with abstracts written in terminology that is understandable to the health-care consumer.

Good news and bad news

How effective are CDs for distributing text, numeric data, and citation indexes? On the plus side, the products we buy generally come with well-designed and powerful search and display software. CDs don't require complex hardware configurations and maintenance is, therefore, usually straightforward. In libraries that are at full capacity and where every linear foot of shelf space is at a premium, CDs are attractive alternatives to bound volumes. Furthermore, CD products, when purchased for single-user configurations, are generally affordable and fit well into the Library's need to budget for subscription costs on an annual basis.

On the down side, CDs are not a great medium for offering campus-wide access, and as MBA student Kitadei noted, once you get used to using PennData from your dorm or office, it's inconvenient to have to go to the library to use a database on CD. The typical library CD, with only an MS-DOS search program, doesn't adapt well to multi-user access, especially over the TCP/IP network. Products now available on the market do allow an MS-DOS session to be opened remotely via Telnet, but Macintosh users find the resulting DOS-in-a-window image non-intuitive, with awkward key mapping and other problems. As well, CD-ROM technology is by itself too slow to support more than a limited number of simultaneous users.

Alternatives to CDs

Recognizing the desirability of PennNet access for many of our CD resources, the Library's Systems Office is looking for solutions that will work with Penn's network infrastructure and diverse desktop environment. One approach that we're currently taking with the Oxford English Dictionary is to license the data in a form that can be mounted on a network- friendly computer that accommodates multiple simultaneous users, rather than try to provide network access to the OED on CD. As vendors make databases available in a choice of formats, this approach may become increasingly viable. However, even allowing for solutions to all the technical hurdles, it's unlikely that every database will be accessible from dorm or office. Licensing costs increase with numbers of simultaneous accesses, and the Library's acquisitions budget is finite. Depending on costs and patterns of use, some resources will probably always be candidates for in-library access.

Do we have what you need?

To see the scope of the Library's CD databases or to find out what's available in a specific subject area, try a co=cd (call number = CD) search on Franklin or call up the guide to "Free Compact Disc and Online Databases" in the Libraries section of PennInfo.