1.0 Introduction: Audience and
Scope of Project
As part of its mission, the Cornell Theory Center (CTC), one of four National Science Foundation-supported supercomputing centers in the US, communicates information about research conducted using its resources (hardware, software, and staff expertise) through a variety of media at several levels of technical detail (http://www.tc.cornell.edu). This work includes the production of a periodic book featuring scientific and engineering applications of interest to a lay audience.
CTC's 1996 online science book, Explorations, is intended for a mixed audience that includes researchers, college students, the media, K-12 students, legislators, and the general public. Our goal was to retain the graphic appeal of hardcopy publications and to enhance the publication through the incorporation of hypermedia technologies. We wanted to involve the viewers at the same time that we entertained them.
Target audiences access the World Wide Web via all possible computing platforms, from high-end workstations with accelerated graphics processors to outdated personal computers donated to schools and libraries. In general, CTC tries to accommodate low-end users when providing online information. Since a goal of this project was to experiment with leading-edge technologies for the communication of science, development of Explorations was not constrained in this way. Instead, we attempted to select new technologies and the hardware they would be ported to early on and aimed the technical development at the midlevel machines.
Emerging technologies featured in Explorations include inline animation using a server push, the frames function that was new with Netscape 2.0*, and viewing of 3D files in Virtual Reality Modeling Language (VRML). By designing with frames, we were able to enhance the visual appeal and the graphical navigation of the book. Frames were suppoorted on all platforms at the time this paper was prepared. In contrast, porting of the technology for viewing VRML files has not been consistent among platforms. Acceptable viewers were not available for Macintosh* or UNIX* platforms at this writing. These factors influenced the development process.
Because we wanted to avoid
presenting the audience with unnecessary surprises or frustrations,
we incorporated a CGI script to detect the reader's browser and
its version when he/she first enters the site. This information
is presented on a gateway page along with links to sites for downloading
the necessary browser and other technologies before entering the
publication (these resources are also accessible from within the
publication). For VRML, we link to the VRML Repository (http://www.sdsc.edu/vrml),
which maintains current technical information as well as access
to downloadable software. In addition, we provide a navigation
tips screen that graphically and succinctly explains the features
of the document and buttonbar functions, a text-based table of
contents, and an index-based search capability.
2.0 Technical Development of Explorations
2.1 Implementation of Frames
Explorations is comprised of a series of feature stories describing research in computational science. Through the use of hypertext, the stories are supported with background information, examples from practical applications related to the research, and links to related sites. We incorporated scientific visualizations wherever possible to illustrate the concepts being presented. The structure of the book emerged through a team effort as we explored the possibilities of the frames function.
As one of our first steps after committing to publishing a multimedia science publication on the Web, we created a changeable storyboard using 4x5 file cards, which provided space for a small representation of each screen type and explanatory notes and comments. These aided us in determining the interrelationships of the publication screens within the whole and within a story. Shifting them around and changing their order facilitated planning by trial and error. Once the flow concept was set, the plan was documented and communicated to the team members via a generalized storyboard diagram created in Adobe PageMaker*. The frame structure emerged from this planning process.
Netscape likens frames to
window panes in the browser screen, each with a view of a different,
but related, part of the site. By clicking in a frame, you can
move deeper, either as that particular frame refreshes itself
with new files, or as it calls up a file into another frame on
the page. In the second model, the original frame remains the
same and serves as a reference point. We used both models in designing
Explorations, but focused our efforts on exploring the power of
The frames function was used in Explorations as a graphical navigation
tool. Here an image map in the left frame holds links to two deeper
layers of the story presented in the large frame. The small frame
(buttonbar, lower right) gives the viewer access to the whole
site as well as help, feedback, and search functions.
At the beginning of the project, we rejected the use of controlled formats such as Adobe Acrobat* or PostScript*. Although they would have provided more design flexibility and artistic control, we saw this as adopting hardcopy technology for online publication, rather than employing new technologies to develop the publication completely in a hypertext environment. We began production of Explorations with the first beta version of Netscape 2.0 (Netscape was estimated to be preferred by approximately three quarters of the browsing audience when we began this project). Cornell University student interns Daniel Cane and Timothy Chi developed the file structure and coding methods used for the Explorations frames.
The use of frames offered several advantages in design and layout of the publication, establishing a "place" for each major component of the pages (graphic image maps, text, illustrations) and, therefore, a consistency of format. Frames also enabled us to maintain a logical and pleasing relationship among the scrolling story, the illustrations, and utility items such as the buttonbar.
All of the top level pages are divided into three frames. On the left, a vertical frame presents a graphic image that is usually a composite of illustrations from the pages at the level below. These images act as graphic sidebars to the pages, enhancing the visual interest at the same time that they present an intuitive graphical guide to the next level in the text. They are sized to fit the initial template and mapped with links to the pages in the hypertext structure to which they refer. Brief text overlays give additional indication of links. The new version of the server software NCSA HTTPd (HTTPd NCSA/1.5.0a), which was installed on our system soon after we started, greatly simplified setting up the image map links.
The major frame for each page is the focal point for that level in the site. Each contains the body of the text, the full illustrations, and often text links to other levels. This is the one frame that we expect to generate scrollbars--since size and font are set by the viewer, we did not attempt to prevent scrollbars here. However, we limited the text length for any segment to no more than three screens in a relatively large font (14 point Times on a Macintosh, "huge" on an SGI). A horizontal frame at the bottom of the page allows the viewer to navigate at a larger scale within the publication. Buttons access the top level of the current story, the entry page for the entire publication, a text-based table of contents, and the navigation tips page.
Any frame on the page will
automatically generate scrollbars within its allotted space if
the files that are called into it are wider or longer than the
space provided. This was inconsistent on different viewing platforms
and it was necessary to compromise, determining the final image
template sizes by trial and error. (There is an HTML tag that
will override the scrollbars, but the results are extremely problematic.)
We attempted to minimize the presence of scrollbars on the pages
by offering a screen sizing page that functions also as a cover
page at the beginning of the site. Viewers are asked to size their
browser window to fit the image on this cover page. Because the
images in the graphic vertical frames are standardized, scrollbars
become necessary only to view oversized illustrations or to scroll
text that is larger than the area of the major frame.
2.2 Additional Features
We elicit feedback from viewers
wherever they may be in Explorations so that we can make continual
improvements in our online science publications. A feedback form
is readily accessible via the buttonbar, and the messages are
sent to the project coordinator as electronic mail.
Explorations is not only an
information book, but also serves as an educational and reference
tool. We incorporated an ALIWEB* CGI search mechanism, available
via the buttonbar, to improve access for students and researchers.
This search engine will permit major Web indexed sites to point
to the articles in Explorations for the entire World Wide Web
audience. Searches are based on the IAFA (Internet Anonymous FTP
Archive) template and look for titles, keywords, and descriptions
that are provided in the source code for individual pages. This
system requires an investment of time by the developers to index
the pages manually, but ensures the quality of their accessibility
to broad searches.
3.0 Telling the Story with Words:
Writing for Hypertext
CTC participated in the development of the National Science Foundation MetaCenter Computational Science Highlights project (http://www.tc.cornell.edu/Research/MetaScience/) during 1994-95, generating new science stories specifically for that site. This experience drove home the importance of breaking apart the text of a traditional, linear feature article into "chunks" of information that are linked and yet stand alone, analogous to, but more complex than, the use of sidebars in conventional print media.
In the hypermedia environment, conventional wisdom suggests that short pages are better. We began with linear features on the research and then took out sections that could become related chunks. Once the story was dissected, it was recast with references to the chunks. Top level pages averaged more than 500 words in length.
Chunks were rewritten to add necessary, though sometimes redundant, information. At this point, chunks often evolved and deepened, especially where we presented practical applications of the research. Chunk length varied from less than 100 to more than 350 words, and this was related to their evolution. The hypertext structure enhances this style of development. By the end of the project, we were writing in hypertext chunks.
While we used images to attract
viewers and as lures to deeper levels of information, we also
wanted to ensure that people read the text. We therefore kept
text and images close together on all the pages, for example interpreting
illustrations on the same page as the image. We wrote captions
after we incorporated animations and images into the structure
of the story to ensure that the context of the illustrations was
4.0 Telling the Story with Pictures:
Incorporating Scientific Visualizations and Illustrations
CTC visualization specialists and individual researchers collaborate to present research results graphically, often in three or more dimensions. In some cases, these visualizations represent subjects, such as the human heart, that are easily recognized by a lay audience; in others, the images may be extremely abstract, for example, a solution surface for a complex series of equations. Inevitably, there are aspects of the visualizations that require careful explanation and interpretation. The choice of format is thus important and the complexity of the information included in the images must be considered in terms of clarity as well as file size.
We were able to incorporate
still images, animations, and 3D files based on researchers' results
to illustrate the stories, although in many instances, these files
required reprocessing. In particular, there was a great deal of
staff time invested in translating 3D files to the VRML format
while controlling for file size and image quality. In addition,
most of the animations required extensive editing and reformatting
before being included in the site.
4.1 Still Images
We sought to place the research in context by providing examples of related applications. Illustrations for these examples were critically important to the publication, both because the structure required them and because they balanced scientific visualizations which were often exotic in appearance and difficult to interpret. These additional still images were chosen for their ability to add interest and to clarify the stories and were gathered from a variety of sources, both hardcopy and electronic. We found these supporting images almost exclusively via the Web. For example, the image of the Matterhorn was taken from a photograph shot in the summer of 1995 by a mountain climber. We found him by searching the Web using the mountain's name as the keyword and were delighted when he agreed to digitize his best image and then provided the file to us free of charge.
Whereas we enhanced the visual
interest of the book by creating the compound images for the vertical
frame, we did not modify the actual images to which these were
linked so that we ensured accuracy of representation of the researchers'
work and fair representation of borrowed images. However, many
scientific visualizations were reformatted, resized, or cropped;
several were extracted from animations. All were reviewed and
approved by the researchers.
The animations presented in the book were made available to us in a number of formats ranging from video tape to MPEG movies. Almost all were too lengthy (input video files generated movies of several hundred megabytes), and often too slow-paced to be translated directly into an online animation. We compromised by identifying clips from the tapes that would illustrate concepts presented in the text. We did not attempt to edit any existing soundtracks to fit the clips.
The animations that appear automatically on the pages that present the four sections of the book (for example, Down to Earth) are server pushes. They are generated, image by image, by the server and sent sequentially to the browser. The viewer does not have to wait for the entire file to be downloaded (as much as 25 megabytes) or to store such large files on their machines. When the viewer has a reasonable connection to the network that is not overloaded at the time of viewing, this is a very satisfying option for presenting animations.
With the exception of the four server push files, virtually all the animations were edited in Adobe Premiere* and output as flattened QuickTime* movies (the format required by our UNIX server). In many cases, we adjusted the quality (increasing the contrast during input, for example, to improve the translation from video tape) and compromised on file size through a variety of approaches in order to keep the files as small as possible. Even so, many still fall outside our desired 5 megabyte upper limit for file size.
We chose the QuickTime format
for several reasons. First, viewers were available for all platforms.
(We make the general UNIX viewer, xanim, available for downloading
from our server.) In addition, because there was no simple editing
approach for the MPEG format, saving MPEG files as QuickTime movies
was the only way to access them without going back to the original
digital files (often no longer available). In addition, QuickTime
plays more smoothly than MPEG on a Macintosh.
4.3 3D Files
Scientific visualization offers intuitively accessible information about research results and is recognized by many researchers as an important part of the scientific process. In the laboratory--whether it is a physical location with test tubes or an immersive environment in cyberspace--3D visualization of data enables exploratory analyses and aids in processes such as interactive steering through databases. With Web-based technologies, the lay viewer now has the opportunity to fly into and through these files in much the same way as the experienced researcher.
We chose to include a limited number of VRML files in features where exploration of a 3D data set would enhance the information presented and the experience of the viewer. This work depended on conversion of visualization files created for CTC users into VRML format.
The two initial applications approach this goal in different ways. The first, a biomolecular model, affords an experience similar to that of the researcher, presenting a challenge to the viewer in terms of navigating the file. It has an embedded hypertext link that functions as an illustration caption, explaining what the viewer sees. This allows the viewer to explore the environment and learn about the chemistry of the enzyme molecule by clicking on a part of it. We intend to expand the use of this technique in future features.
The second example of 3D illustration, a set of sample files from a geographic information systems (GIS) database of New York State, allows the viewer to fly over selected regions of the state looking at the distribution of vegetation, for example, and is geared more toward entertainment.
To accommodate viewers new
to VRML, we grouped the VRML files together with access through
an introductory page, Virtual Reality Tours, where introductory
information and a link to the VRML repository are provided. The
repository maintains up-to-date information on software and formats.
Moving from the Virtual Reality Tours page into a model, viewers
find a user interface (designed by Cornell University undergraduate
Daniel Switkin) in the form of a remote control. At this point,
they select a specific model, load it, and fly into it. Viewers
exit the models through links in the models themselves or through
text links on the Virtual Reality Tours page, which remains visible
during their VRML session.
5.0 Self-evaluation and Future
Development of Explorations
ended on April 1, 1996 when it was released publically, and while
the site has been refined in response to feedback, no major changes
have been made to the publication since. Our aim in developing
Explorations was to apply the latest available technologies to
create a highly interactive, exciting, and information-filled
multimedia experience through the World Wide Web. This forced
us to explore the limits of such new technology and to develop
new capabilities for online documents. This is an ongoing process.
5.1 Overall Design
We experienced an unwelcome design constraint working for cross-platform application. Because of the effect that differences in screen resolution have on the size of the images on the page, we enlarged the design as much as possible to make the publication look reasonable on high resolution screens; this necessitated additional vertical scrolling for low-end Macintosh screens (13" RGB monitors). In the future, we hope that new technologies such as Java* will resolve this problem by allowing the images to be resized on the fly.
This was our first use of
frames and we hope that the artificial boundaries they enforced
can be overcome though design and a more flexible frame structure
similar to the grid system used in conventional publications.
Depending on the evolution of Web standards, we may look for alternatives
to the frames approach to page design. Access to the broadest
possible audience will be an important factor in the decision-making
Five hundred words is probably too much text to include in one piece of hypertext. To further reduce the size of the text pages we will have to rethink our approach to telling the stories. We are also considering a discrete method for providing hypertext definitions--one that will not detract from the flow of the stories for those choosing not to access the definitions.
To enhance the illustration
captions, we plan to incorporate audio explanations of the animations
and still images into the features. In addition, sound files from
scientific data will be included whenever possible and we are
currently studying sound file formats for these files
In this publication, we did not pay a lot of attention to image file size reduction. This will be a priority in upcoming publications. To make this easier, we have acquired Equilibrium Technology's De-Babelizer*. We will also reconsider the use of the JPEG format. We had rejected JPEG in favor of the GIF* format, which permits transparent images, interlacing, and viewing as inline or spawned images on any browser.
VRML and animated illustrations
in online publications can be very effective. However, they are
not easy to incorporate into the page. Several limitations exist;
some will be resolved by advances in Web technology. Others involve
careful planning of the publication and close communication with
the researchers/visualization specialists. For example, we hope
that providing links to sources of information about VRML and
download sites for browsers will limit the frustration of those
without this capability. However, lumping these illustrations
together makes it easier for people only interested in VRML to
browse the files and leave without experiencing the rest of the
site--for better or worse depending on your point of view. We
look forward to the time when inline VRML browsers are commonplace.
6.0 Future Plans
In the next version we will enhance interactivity by richer use of VRML and possibly through interactive software applets. In addition, there is a potential for the development of interrelated themes within a more interactive publication structure. For example, intermediate pages between treatments of particle physics concepts which appear in both astrophysics and nuclear physics features.
By nature, hypermedia publications
depend on the availability of images, animations, sound, and 3D
files. As mentioned above, 3D files created by research teams
in the process of scientific work did not necessarily suit the
editorial and production needs of Explorations. Developing effective
illustrations for online publication requires early contact and
ongoing communication with the researchers as well as independent
resources and expertise to translate and edit files for transfer
and presentation on the World Wide Web. The importance of this
interaction will only increase as science features become richer
and more interactive.
Special thanks: We would like to acknowledge the contributions of Linda Callahan, CTC director of external relations, and Dan Dwyer, leader of CTC's Online Information Project, and to thank visualization experts Richard Gillilan, Chris Pelkie, Wayne Lytle, and Bruce Land for their help in many different ways during the course of the project.
This work was conducted as
part of the production of the CTC's online science book, Explorations.
CTC, one of four high performance computing and communications
centers supported by the National Science Foundation, operates
a 512-processor IBM SP system. Activities of the Center are also
funded by New York State, the Advanced Research Projects Agency,
the National Center for Research Resources at the National Institutes
of Health, IBM, and other members of CTC's Corporate Partnership
* Trademark or Registered trademark