Appendix to WWW Ad Hoc Report on the SLAC Home Page

Joan M. Winters

16 Dec 1997





From 1976 till the present I have been interested and involved in learning about the human factors of the human-computer interface. These activities include chairing a committee that investigated how people actually used online documentation to solve their own specific problems and their satisfaction levels with the various methods they tried. This research held up so well that it was published by the ACM Special Interest Group on Computer & Human Interaction eight years later. I served as Deputy and Manager of the SHARE Human Factors Project for nine years and heard hundreds of hours of talks by human factors researchers. I helped design the externals of system modifications and implemented the consequent local documentation changes throughout VM HELP, maintaining the updates over versions of the operating system using the same management system as Systems did for code. This effort entailed modifying at least a hundred files and installing them with thousands of unmodified IBM HELP files. The experience taught me to think about large systems of online documentation over time. Since 1993 I have been the owner of the SLAC Home Page and a number of related ones, though with increasingly shared authority since the central redesign installed in December 1995.

People have told me that this long-term involvement in on-line documentation doesnít count because the Web has changed everything.

People havenít changed. As before, sometimes they are learning, sometimes problem-solving, and sometimes refreshing their knowledge. Only the online applications to help them have significantly improved since the creation of the World Wide Web in 1990 and its subsequent evolution.

But at this point I also have significant experience in designing and evolving the central information space of the SLAC Web. I designed the first official SLAC Home Page and about thirty related pages including the precursor of the SLAC Welcome Page. I was complimented for the lack of perturbation that installation caused users (November 1993), an installation process I designed and implemented. I came up with the first common page elements. All but one are in the current set. I actively solicited additional content from across the Lab via personal contact and an online suggestion page. I was the primary designer and implementer of the live prototype in August 1995 to gain user feedback on that redesign of the central space. I am also the author of many of the early SLAC Web issues documents, e.g., ones on privacy, URL naming, and the concept of production Web space. I have designed and implemented the central AFS production file structure from the beginning.



The almost final version of the report of the WWWCCís WWW Ad Hoc Committee on the SLAC Home Page was distributed December 11th. The final report is scheduled to be given to the WWWCC December 16th. In the time available, here are some comments on aspects of that report as well as a summary of my views on important factors in the design and maintenance of the SLAC Home Page and its closely related pages.


SLAC Home Page Design Goals

The SLAC Home Page is intended to be a powerful, robust, and comfortable place for regular members of the globally distributed, SLAC working community to traverse again and again and again. The SLAC Home Page is not primarily a place for people learning about SLAC, whether they be virtual visitors passing through the site or people new to the working community. The SLAC Welcome Page has been designed for them and is the default page SLAC presents to the world at In addition, Getting Started, SLAC Introduction to WWW, and other pages are intended to help new members of the community get up to speed quickly.

Members of the SLAC working community have different backgrounds and purposes. They prefer different cognitive styles. Some prefer a hierarchy of information with limited information per page. Others prefer as much information as possible organized intelligibly in one flat space. They are in different cognitive states. They may be learning, problem-solving, or refreshing their knowledge. They are situated in different environments. They use different platforms and browsers and access SLAC across a wide range of network bandwidths.

Designing one general workplace for audiences with all these different characteristics is particularly challenging. SLAC has addressed this goal by laying out a carefully layered information architecture, into which are designed several forms of access. These include the structure of the links on the SLAC Home and other pages, the design of the URL name space, an index of local links that may be searched, and two different formats for the SLAC Home Page.

Achieving the goal includes designing consistently across pages, not just within them. Not only are content and presentation design important for usability, but also interaction design.


The basic design assumptions for the SLAC Home Page include:

This page is a workplace for users, a space where most people spend most of their time being familiar with the general layout and contents.

This page contains reference information and may make use of SLAC jargon.

Major goals include:

Secondarily, this page may passively teach concepts important to some major set of SLAC users, such as that PPRC stands for Polarized Photocathode Research Collaboration, ADCC for Associate Directors' Committee on Computing, and ILR-TRC for International Linear Collider Technical Review Committee, when this material does not interfere with the primary focus.

SLAC Home Page in Two Formats

Since December 1995, the SLAC Home Page has come in both a Highlighted and Detailed format. The Highlighted one is the top of a two-level hierarchy where the second level pages, one per major category on the SLAC Home Page, are called Secondary SLAC Home Pages. The Detailed one has the same information in the same order in one flat page. One caveat: Because of the greater availability of real estate in the Highlighted hierarchy, link text is usually spelled out to reflect closely the visual page title; on the Detailed page with its tight real estate, acronyms and two or three-word title subsets are usually used instead. For example, in the current SLAC Divisions, Groups, & Programs category, it is "SLAC Computing Services (SCS) Group" on the Secondary SLAC Home Page but "SCS" on the Detailed SLAC Home Page.

Providing these two formats is an attempt to meet two distinct cognitive styles of users. One format does not fit all. As one user Edgar Whipple said about why he prefers the Highlighted version, "Öit fits on one screen. I donít have to scroll to see all the major headings. I prefer my hierarchies hierarchical and not flattened." On the other hand, another user Lois White was equally articulate about why she prefers the Detailed version, "Ö I find paths to the things I want very quickly, because they are all there on one page."

These people are not unique. Usage statistics for the week of December 6-13, 1997, indicate approximately 35% used the Highlighted and 65% used the Detailed SLAC Home Page (of 3038 non-cached hits total). Of those in the edu.stanford.slac reversed domain, that is, those users pretty clearly in the SLAC working community, the usage shifts to around 25% Highlighted and 75% Detailed. The Highlighted page is hit from more different domains. These trends have been clear since a few months after the installation, though the preference for Detailed is more pronounced this time than times previously summarized.

Some have concluded that these preferences are due to links being in unexpected categories. Although this problem probably has some bearing, e.g., on where to look for Seminars, I am sure it is not the only significant factor from user comments over the years like those above from Whipple and White. Whether one prefers hierarchies or flat spaces seems deeply embedded in the way one thinks.

The pros and cons of hierarchies also bring to mind an ACM SIGCHI panel at the annual conference in the mid-eighties in San Francisco. As I remember, about two thirds of the audience were already using GUI interfaces. There was extended discussion about the difficulty GUI users had figuring out where they were. As a user of VM, a primarily line mode interface, I was surprised by the problem. Now that I use GUI interfaces, I have a much better understanding. When information is cut into small chunks and viewed sequentially, it is easy to get lost.

Although the Ad Hoc Committee decided to continue the two SLAC Home Page formats for the moment, in its deliberations there have been continuing efforts, some successful, to reduce the number of links on the Detailed SLAC Home Page, thus making it a less rich, flat space. Even last week some thought that the goal is to "roll up" links within sections like Computing and BIS to make the SLAC space more "Web-like", where "Web-like" is viewed as non-scrolling and, hence, more hierarchical. Users of the SLAC Home Page would be increasingly forced to go through a topicís top-level link to get to any of the lower- level ones. Another member of the committee spoke of objections from colleagues elsewhere about having two formats.

The two formats are not for visitors to the SLAC site. They are for active working members of the SLAC community. Migrating to one format with fewer links seems counter-indicated by the usage data we have, some strongly felt direct user feedback, and by concerns among the professional computer-human interaction community about fragmentation. Scrolling can be part of a very effective strategy for finding information one uses regularly.


Some Rules and Practices

The SLAC Home Page is a complex, carefully layered place with a deceptively simple-seeming center.

It is a nexus of competition.

To create a powerful, robust, and comfortable space, many design rules and practices must be followed. The procedure is not usually a cookbook but must carefully balance different aspects in light of particular circumstances.

URL naming is one important element I have not yet addressed. If names are carefully thought out with an eye towards likely additions and naming conventions consistently followed, the result can be powerful. As one experienced author Ilse Vinson said:

Joan, Today I was working with the WWW telecommunications pages, and I noticed that once again I really appreciated certain conventions that you established and that we all follow quite consistently now, such [as] directory names in lower case and singular. It really takes a lot of the guesswork out of generating and remembering names like: should it be singular or should it be plural? Beyond that , I also appreciate the clarity of organization: grp and functional page names make a lot of sense to me. If I know what Iím looking for but not necessarily that exact name, I can usually find it.

Given the constraints of time, for more information contact me for a copy of the slides from a talk at SHARE on designing the central SLAC Web space. If there is interest, I would be happy to write up the rules and guidelines Iíve evolved over the years of developing the SLAC Home Page.


Perceived Problems and Suggestions for Improvement

Some of the problems I see with the current draft of the SLAC Home Page developed by the WWW Ad Hoc Committee and suggestions for reducing their impact follow. In some cases these problems affect the current production SLAC Home Page as well.

There are a number of features of the draft that I think will reduce problems with the current production SLAC Home Page, or are likely to. Only the event will tell the tale. These features include the new SLAC Home Page in Transition section, the cross-link section among the Secondary SLAC Home Pages, and some of the new major category names. The vertical rather than horizontal lists of links are a strong step in the right direction, particularly as the implementation tables are "squishable" so that they will be useful under diverse circumstances. I also think the link column in the top right has benefits over the current button bar but needs a bit more work.

To be a smooth, effective workplace, the SLAC Home Page has to reflect a broad understanding of the diverse needs of the Lab.

Specific Comments

This list in non-exhaustive.

The main information categories have insufficient dispersion. Most task-oriented links tend to fall into either the Research Program or Working at SLAC. If the proposals to fold Scientific Information and Computing into the first two categories, thereby reducing the number of links on the SLAC Home Page and leaving only two "functional" categories, succeed, the problem will be exacerbated. (In addition there are, of course, the Organization and the new SLAC Home Page in Transition categories that view the Lab from those different perspectives.) Some subcategories could be improved also, e.g., Web Forms in Working at SLAC and General Information in Computing.

Titles are no longer kept distinct from links. See the Business Information Services (BIS) subsection.

This mixing of roles makes the page harder to parse; hence it is less quick and comfortable to use.

Items appear in surprising categories. For example, as the subjects of Computing and Communications grow ever closer together in the world beyond SLAC, as well as at SLAC, the draft SLAC Home Page splits the current top-level Computing and Communications section. This information now appears in a shrunken Computing section and a new subsection named Communications and Directories in Working at SLAC. "Accelerator Physics" appears in Synchrotron Radiation (SSRL) rather than Accelerator Research & Development; "SPEAR Status" likewise, rather than in Accelerator Operations. Some find the Faculty and User Information subcategories surprising in the Research Program. The ESnet multi-institutional "Network Monitoring Task Force" appears in the task-oriented General Information subsection in what is otherwise a SLAC Computing section. Putting another multi-institutional link "ILC-TRC" in the Task Forces and Committees subsection in the middle of the otherwise SLAC Organization section seems inappropriate at best.

Expanded titles are no longer used on the Secondary SLAC Home Pages. See, for example, "SLAC Admin Handbook" and "Stanford Admin Web" on the Working at SLAC Secondary SLAC Home Page. Using the visual page titles "SLAC Administrative Services Handbook" and "Stanford University Administrative Resources" would be clearer, and the space is available. Even more disconcerting are "Property Transfer Form", which goes to a page titled "Property Transfer Notification" and "ES&H Training Form", which goes to a page titled "ES&H Training at SLAC: Training Schedule Through December, 1997 and On-line Registration Form." Similarly, "SLAC Computing Services (SCS) Group" would be clearer on the Organization Secondary SLAC Home Page than the current "SCS".

"Link from" text does not match "link to" text. For example, "Particle Astrophysics (GLAST)" in Research Program goes to a page titled "GLAST: the Gamma-ray Large Area Space Telescope." Users are likely to look for subtle differences because of the difference in terms and wonder if the link is as intended. The SLAC Home Page is for working members of the community who mostly have become familiar with the material.

I would recommend changing the link text to "GLAST" on the Detailed SLAC Home Page and "Gamma-Ray Large Area Space Telescope (GLAST)" on the Research Program Secondary SLAC Home Page as well as the page title to "Gamma-Ray Large Area Space Telescope (GLAST): an orbiting telescope for high-energy gamma rays".

The effectiveness of the Highlighted SLAC Home Page seems seriously diminished. It is certainly politically easier not to select the specific "nominated" links, but only having links to the Secondary SLAC Home Pages left forces people always to traverse the second level of the hierarchy. I wonder if this loss in functionality will increase peopleís use of bookmarks rather than the SLAC Home Page at all, with the consequent loss in organizational familiarity.

The major Information Elsewhere section has been removed. This means SLAC context is harder to determine. It also means the quick reference material that has been very quickly accessible will now be slower to obtain. The passive educational function it has served will also be lost.

To the extent that the "More" links have been removed, e.g., "More Platforms" in Computing, there will be no easy room for expansion. This lack will force functional information into Group and Department pages, counter to current recommendations in the trade to organize information by usersí perspectives on their work, not by the institutionís structure.

The inconsistent contents of the top right menu column of general-access links is confusing. The title and link column are intermixed. As one moves across the pages, it helps to position oneself if the column remains the same.

No selection criteria (other than usage) have been articulated for inclusion in the column as it needs to evolve over time. I have suggested the following:

To some extent, these criteria also may also apply to inclusion of a link in the body of the SLAC Home Page. To which I add the criterion that a given link appear only once in the body of links on the SLAC Home Page (the taxonomy). A link may also appear up to once in the "metalanguage" links, those "navigational" links like the ones in the top right menu column.

Using a tailored form of the list of links to the Secondary SLAC Home Pages near the top of each one is maintenance-heavy and occasionally can interfere with usefulness

The top of the SLAC Home Page appears cluttered. Putting the Contents and SLAC Announcements next to each other seems particularly distracting. Given some peopleís strong desire to put fill up the right hand side to maximize the information available in one window without scrolling, some may like this design. It seems to be a good candidate for research into SLAC usersí preferences.

Use of italics that supported immediate recognition of newsletter titles has been dropped. Italics display poorly on low-end systems, especially old Macs. But in any complex information space like the SLAC Home Page, the benefits of using peopleís pre-existing knowledge (document titles appear as italics) are strong, too. One needs as many reasonable ways as possible to distinguish information categories. Taking advantage of conventions supports almost automatic transmission of information (a document title in this case). Before we give up this easy method of discrimination, we should size the italics problem. Is it a serious one for a significant number of users today? Note that italics are also currently used for SLACSpeak definitional links to distinguish them from links to information pages at user request.

Procedural Recommendations

The basic taxonomy (main and secondary information categories) should be tested by research. There are some inexpensive techniques for gaining insight into the underlying structure of information. The SLAC Home Page will be an endless source of time-wasting behavior and user frustration to the extent Lab politics are an overriding design criterion.

The SLAC Home Page Coordinator needs design authority. For the past couple of years there has been a tendency for single individuals and committees who look at the SLAC Home Page cursorily to work to have it modified to address their immediate interests. This has led in part to an unbalanced, inconsistent design. An advisory committee broadly representative of the Lab and with willingness to learn in depth about Web workplace design would be an essential element of this approach.

The SLAC Home Page Coordinator needs to be on the WWWCC ex officio at a minimum. This propinquity is important for mutual education about design issues and user needs. Often specific terms and layout elements can affect the usability of the design positively or negatively.

The SLAC Home Page Coordinator needs authority to resolve terminology differences across link transitions. Working with the page owners there needs to be an institutional commitment to come to common terminology and recognizable formats across link transitions.

The central URL and file name design should stay with the Web Support Group. It is too tightly bound to certain aspects of server administration to move to an unrelated group.