CMU-ITC-079

Carnegie Mellon's Andrew:

The Evolving User Interface of the Messages Program

Christina Haas, Consultant for Interface Design and User Testing

Daniel Boyarski, Graphic Designer and Consultant for Interface Design

Nathaniel Borenstein, System Designer and author of the Messages Program

Information Technology Center

Carnegie Mellon University

Pittsburgh, PA 15213

(412) 268-6717

Introduction

The Andrew project at Carnegie Mellon University is a prototype computing environment foruniversities, developed by the Information Technology Center, a joint venture of IBM and CMU(Morris, et al, 1986; Morris, 1988). The Andrew system includes the Andrew File System, alarge distributed network file system (Howard, 1988); the Andrew Toolkit, an object-orientedenvironment to support user interface software development (Palay, et al, 1988); and theAndrew Message System, a multi-media mail and bulletin board system which utilizes the Vicenetwork (Borenstein, 1988; Rosenberg, et al, 1987).

Designing the user interface for a computer system such as Andrew is a complex task, involvinga variety of issues, such as visual/verbal communication, cognitive psychology, system design,the written word, usability testing, etc. Contributing to the Andrew project over the last severalyears have been individuals with a range of different backgrounds and academic disciplinesfrom Graphic Design to Computer Science, from Engineering to Rhetoric. These individualsbring different perspectives on how to design and produce the user interface for a system andthe resulting interdisciplinary give-and-take has been crucial to the design and development ofAndrew's User Interface.

The Andrew project is now five years old; this paper focuses on one aspect of Andrew--the

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Message System--in which the user interface has continued to evolve in useful, innovative, andproductive ways. We begin with a brief overview of the Andrew Message System as it existstoday. Then we describe some of the improvements made to the Messages program during thepast year by examining two strands of work which have contributed significantly to the evolvinguser interface of the Andrew Message System: 1) the contributions of graphic designers inanalyzing issues of visual/verbal communication; and 2) contributions from human factors testingand usability analysis examining how actual users learn, understand, and use the AndrewMessage System.

The Andrew Message System Today

The Andrew Message System (AMS) is a portable, distributed, multi-media, multi-interfacesystem for reading and sending mail and bulletin board (bboard) messages. The AMS supportsmulti-media messages, which may include line drawings, hierarchical drawings, spreadsheets,raster images, animations, and equations. It is explicitly designed to support a huge database ofmessages and an enormous user community. At CMU, it services over 1600 bboards, includingnetnews, the Dow Jones information service broadtape, and bboards on which newspapercartoons appear as raster images.

The system incorporates an automatic "white pages" for doing name Iookups, includingphonetic matching of misspelled names. In addition, the system supports a number of advancedfeatures such as voting on multiple-choice questions, private bboards, shared mailboxes, andautomatic classification of incoming mail messages. The server-based architecture makes iteasy for client interfaces to be ported to or built on almost any computer. For instance,associates of the Center for Educational Computing in English have developed the Commentsprogram, which allows teachers to comment on student papers electronically (Neuwirth, 1988).Currently, interfaces to the AMS run on IBM RTs, DEC MicroVaxes, Suns, IBM PC's,Macintoshes, and Vax UNIX and VMS timesharing systems. For more detailed descriptions ofthe Andrew Message System, see Borenstein, et al (1988) and Rosenberg et al (1988).

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Figure 1. Reading Messages.

Thousands of students, faculty, and staff have been using the system during its developmentover the last few years for reading and sending personal mail, and for reading and posting toacademic, technical, and general interest bulletin boards. Users are alerted--via a lit icon--whenthey have new personal mail and the mail and bboard facilities share a common interface.Figure 1 shows the Messages window, used for reading mail and bboards. There are threeregions: the upper region, or folder region, which contains a list of subscribed "folders"(including a mail folder) which have new messages. The center region (or captions region)shows the titles, senders, and dates of the new messages in the selected folder (which isindicated as bold in the folders regions). The bottom region, or message region, shows the textof the message selected in the captions region. How the space within the messages window isallocated has been the focus of much discussion and several rounds of user testing and isdiscussed in more detail below.

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Sending or replying to mail is done is a separate window (running under the same program) sothat users may compose messages and view messages simultaneously. In Messages, usersuse the mouse, menus, scroll bars and other features much as they do in other Andrewapplications. In SendMessage, text in entered, deleted, and moved as it is in the Andreweditors. Within SendMessage users can use general formatting features such as titles, specialfonts, and indented text. In addition, the AMS is a multi-media mail system: users can insertdrawings, tables, raster images and other insets. Figure 2 shows the Andrew screen of oneuser; the user is replying (in the lower window) to a message she has just read (in the upperwindow.) Note the mail icon in the Monitor window which indicates that the user has one pieceof new mail and the drawing which the user has created within the sendmessage window.

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Figure 2. Reading and Sending Messages.

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While the number of available bboards may number in the thousands, when users invoke theMessages program (by typing 'messages' in the typescript window or by using a pop-up menu)they typically see only a few bulletin boards: those to which they are subscribed which havenew postings. Figure 3 shows a tree structure which symbolizes the configuration of Messagesfor one user, Pat. In addition to personal mail, Pat is subscribed to six bulletin boards, includingofficial.andrew, a bulletin board containing official announcements such as printer down timesand to which new users are automatically subscribed; academic.englishlOOe, the class bulletinboard for Pat's English class; and ext.nn.rec.skydiving, an external netnews bulletin board.

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Figure 3. Pat's Messages

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Improving the AMS Interface: The Graphic Designer's Perspective

Goals

When we first started discussing the physical appearance of Messages, we wrote down ourgoals:

Clarity in the presentation of information is our primary goal.

Clarity can be achieved a number of ways:1. A logical hierarchy to the presentation of the information:

message folders first, message captions second, the message text third.(macro view to micro view)

2. Consistency in the location of the information. Surprises are not alwaysappreciated.

3. Consistency in the size of window sections.4. Readable typography. This refers to the arrangement of the type/text within each of

the sections; it also refers to the typeface (font) and type sizes in use, line length, and linespacing.

A second goal is to allow the user to read, reply, post, and organize one's messages easily andefficiently. It has been proven that when a user has a positive experience running a program,he/she will gladly return to this program the next time a similar task needs to be done.

Icons

The task was to show a distinction between mail and bboard postings in the middle section ofthe messages window, where the message captions are displayed. Icons were considered,since they often function as a visual shorthand for words. The design process initially involved :

1. understanding the content of each icon: what is it to say?2. understanding the location of each icon: where will it appear, and how often; will it

be in the company of other icons or text?3. understanding other constraints: how large can the icon be; does it have to line up

with type/text or other icons; how large of a family of icons will this involve?

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The Mail IconSeveral ideas were considered, including an envelope and a traditional "rural" mailbox. Thismailbox, we argued, was not appropriate, given the fact that not many people today own such amailbox, while others have never even seen such a mailbox. Today's apartment dwellers aremore familiar with wall mail slots, which are opened and locked with a key. Therefore, the imageof the "rural" mailbox, mounted on a post, with its little flag, is meaningless to a larger andlarger segment of our population. (The same argument can be made about an hourglass toindicate the passing of time.)

The image of an envelope with a stamp and an address became our recommendation. This is afamiliar image, one that suggests new mail; a positive connotation. We preferred this to the backof an envelope because we consider the back of an envelope to be a rather passive image(waiting for some action to be taken), while the front of an envelope with stamp and address isa more active one.

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Figure 4. Mail Icon Options

The Bboard IconIn contrast to the envelope for the mail icon (a horizontal rectangle), the icon for a bulletin boardmessage became a vertical piece of paper with a folded corner (now part of our visualvocabulary for display graphics). This icon was fairly easy to design, given the visual context ofa bulletin board with multiple pieces of paper tacked up on it. Our campus is filled with suchbulletin boards, not unlike other campuses and other environments where people need tocommunicate with one another.

Various iterations on this icon explored the visual suggestion of tacks at the page's corners (tooface-like), and the suggestion of text on the page (too busy). The directness and simplicity ofthe single page was clear enough.

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The Other Icons

After the two basic message icons were accepted, we proceeded with expanding the family oficons. Without going into detail, here are the other icons and their functions:

Figure 6. Icons: New Mail, Deleted Mail, New Bboard Posting, Delected Bboard Posting

The "check mark" is an icon that has been around the ITC for many years and has proven itsvalue as the iconic indicator that says, this message has been read. There was no reason forme to improve on it.

[] 27-Apr-88 Preface - Ann Ungar (3043+0)[] 28-Apr-88 Partic,pating in EXPRES Study - Charles Huff (2654")[] 28-Apr-88 A questionnaire - Charles Huff (9647*)i"'_ 28-Apz-88 Z_ort¢_t tr=tst./o_ - Mzziz G. Wz,.'tlov,, (183+0).......

i_ 29-Apz-88 Re: O'SEzVZXP_t_ - Dzvid TiZbzook (160+0>

[] 3-May-88 Q_estionn=ire reminder, - Charles Huff (761")[] 3-May-88 Message loggzng - Charles Huff (757*)

.J 6-Ma¥-88 Mcl_rCx_ft_m Tom Hum@ - John Howard (382+0)/__._.10-May-88 Messages logg_Hg- Chorles Huff (849*)

[] 10-May-88 Aatomc_ted Questtbnnazre - Charles Huff (831")[] 10-May-88 Commun¢cation Questtonn_re- Charles Huff (10186*)

Figure 7. Middle Section of Messages Window with Icons

Typography

Along with the discussion on allocating screen space within the Messages window (see latersection of this paper), was the task of making recommendations on typefaces (fonts), sizes, andweights, as well as the arrangement of this type in the various window sections.

The typefaces available within the Andrew system are a serif font (like Times Roman), a sansserif font (like Helvetica), and a fixed-width typewriter font (like Courier). For legibility reasons,we selected the serif font for all the information display in messages. Weight and size changeswithin the serif family, along with formatting options, gave me enough signalling devices for aclear hierarchical structure of the information.

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As Messages evolved, we had to consider ways to indicate:a message that has not been reada message that has been reada message that has been deleted

A Message That Has Not Been ReadRecommendation: All message captions are listed in one typeface (serif) and a single weight(normal), with italics used to call out the message title. The caption line includes four pieces ofinformation: the date the message was posted, the message title, the author, and the numberof words in the body of the message. The message title is italicized, to visually separate it fromthe rest of the information. It is given added emphasis with a character space between it andthe date, and a flush left arrangement, thereby giving the user easy visual access. The goalhere was to give it visibility and accessibility, and not to have it appear buried in the grayness ofthe text.

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"¢-_"25-Apr-88 Re: _ few questzons - Nathaniel Borenstein (1935+0)Q 26-Apr-88 Re: Text gnd "_0' - Zalman Stern (313+0)

iiiil [_ 26-Apr-88 Re: Text _nd '_0' - Tom Neuendortfer (55_,+Q)[_ 27-Apr-88 Fwd:Afe_questions/bugs- Nathaniel Borenstein (3424+0)Q 27-Apr-88 Object Extenswn L_ngu_ge M.. - Fred Hansen (762)

iiii_{i [_ 29-Apt-88 Re: A Jew questions/bugs - Mark Steven Sherman (2005+0)Q Zg-Apr-88 V_lue, cel, gnd _rbiter mee.. - Tom Neuendorffer (466+0)

3-May-88Needhelp ,.- a,h e,Bore.,,e,n[_ 3-May-88 Re: Need help tnstaZLV_gfo,. - Mark Steven Sherman (852+0)

[_ 3-May-88 l STILL need help, guys,.. - Nathaniel Barenstein (235+0)[_ 3-May-88 Bug tn EZ - Nathaniel Borenstein (274)

[_ 3-May-88 Re: Need help t>_st_Zlingfo.. - John Howard (599+0)[_ 9-May-88 A codefrggment- Nathaniel Borenstein (464+0)[_ 9-May-88 Re: A code[ragment - Zaknan Stern (697+0)[_ 10-May-88 More onfdh&dfgbsence - Nathaniel Borenstein (806+1)

Figure 8. Messages that Have Not Been Read

Our recommendation involved the combined communicative potential of words and icons. Asshown above, the icons are used as scanning devices, then as bits of information (new, hasbeen read, deleted) and as pointers to the message captions which sit next to them on thesame baseline.

The middle window section employs several margins (tabs) for a clear, hierarchical structure.The first margin contains the icons, the second one contains the date, and the third margincontains the message title, its author, and the number of words in the message itself. We tried anew margin for each bit of information, but the various lengths in the titles and the authors'names proved to be a problem. It became difficult to read across a rather long horizontal linethat was peppered with short and long bits of type and five margins.

A Message That Is Selected and ReadTo select a particular caption, the cursor (a left pointing arrow) is pointed to that caption and amouse button is clicked. The result is that the entire line of type turns bold. The body of themessage appears in the bottom section of the window. This rather obvious, but very clearsignal, is most effective in the midst of many titles. The single bold line stands out clearly

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against the field of grey type. This signal is used consistently throughout the Messagesprogram, and the Andrew system. When a new caption is selected, the old caption returns to itsoriginal normal weight, while the newly selected one turns bold. Accordingly, the icon changesfrom the mail or bboard icon to a check mark icon, signifying that the user has read thatmessage. The physical change from the envelope or page icon to check mark icon is a clearvisual signal that a change in status has occurred.

•I 24-Apr-88 bugs in ez - Fred Hansen (434)[] 25-Apr-88 Re: ¢/ew questions - Nathaniel Borenstein (1935+0)[] ?..6-Apt-88 Re: Text ¢_nd "V)' - Zalman Stern (313+0)[] 26-Apr-88 Re: Text and '_0' - Tom Neuendorffer (551+0)[] 27-Apr-88 Fwd: A few questions/&ugs - Nathaniel Borenstcin (3424+0)[] 27-Apr-88 Object Extension L_ngu_ge M.. - Fred Hansen (762)

[] 29-Apr-88 Re: A/ew questionsbugs - Mark Steven Sherman (2005+0)_/ 29-Apr-88 Value, ceZ,and axbiter mee.. - Tom Neuendorffer (466+0)

.__3-Ma¥-88 Need help _s_fonts .. - Nathaniel Borenstein (1398+0)-May-88 Re: Need help inst_ltz_zg fo.. - John Howard (470+0)

[_ 3-May-88 Re: Need kelp instczlling]o., - Mark Steven Sherman (852+0)[] 3-May-88 I STILL need kelp, guys...- NathanJel Borenstein (235+0)[] 3-May-88 Bug _n EZ- Nathaniel Borenstein (274)[] 3-May-88 Re: 57eed help inst_Eing fo.. - John Howard (599+0)[] 9-May-88 A codefr_gr_ent- Nathaniel Borenstein (464+0)[] 9-May-88 Re: A codefr_zgment- Zalman Stern (697+0)[] 10-May-88 More on fdbbdf absence - Nathaniel Borenstein (806+1)

Figure 9. A Message that is Selected and Read

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A Message That Is DeletedDeleting a message is accomplished with a menu item selection. When this is done, the captionline changes in appearance: it shrinks to a smallerpoint size.This was actually therecommendation of Nathaniel Borenstein, the creator of Messages. Coupled with that change inappearance, the icon changes to a faded envelope or page. Seen in the context of Messages,these changes are clear signals to the user.

I_ 27-Apr-88 Preface - Ann Ungar (3043+0)[] 28-Apr-88 Participating in EXPRES Study - Charles HuE (2654*)

[] 28-Alor-88 A q_estionnaire - Charles Huff (9647*)[3 2$-Apz-e$ I=_p_rtalt fusn'#_ - Mafia G. Wzdto_, (153+0)

29-Ap1-88 R_': 6PS"_,,cV[AtP_'tS - bzvid Tf.lbzoek (160+0)

[] 3-May-88 Questionn_'re remznder. - Charles Huff (761")[] 3-May-88 Message logging - Charles Huff (757*)

,,,/ f-May-g8 MaWria_fr_m Tom HaZy- John Howard (382+0),/ 10-May-88 Messages _oggtng- Charles Huff (849*)[_ 10-May-88 Automated Questionnaire - Charles Huff (831")[] 10-May-88 Coz_muntcation Q_estionnczzre- CharlesHuff(10186*)

Figure 10. Several Messages: Unread, Selected, Deleted

GenerallyObserving ourselves and other people using Messages, we are reminded that one can movearound rapidly, selecting, reading, deleting, moving on. Therefore, the visual cues and signalshave to be visible, recognizable, and clear. Icons and typographic cues that make intuitivesense are easily remembered by new and/or occasional users. They allow the user toconcentrate on the task at hand, and get through the task as efficiently and effortlessly aspossible.

Improving the AMS Interface: User Testing

The AMS interface has also benefitted from testing the system with real users. Not only is thesystem used by a group of sophisticated and vocal users at the Information Technology Center,but several iterations of user testing have been conducted with users from the campuscommunity with varying degrees of expertise. We have conducted two kinds of user tests: 1)general, exploratory studies to determine how people actually use the Andrew Message System,and 2) more focused, issue-driven experiments designed to answer specific questions about theinterface. Each of these strands of testing has been important and fruitful: the exploratorytesting has allowed us to learn from users and often to be "surprised" by how they use theAndrew Message System in a way that wouldn't be possible with more controlled studies; theissue-driven studies have allowed us to address specific questions about problematic features ofthe Andrew Message System. Often the exploratory studies have unearthed questions whichwe examined more carefully with controlled studies. Below we give examples of each of thesestrands of user testing that have contributed to the user interface of the Andrew MessageSystem.

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Exploratory Testing

The purpose of the exploratory testing is to get more information: about who uses Messages,how often, and for what purposes; about problems or concerns that users have; and aboutusers' opinions of the Andrew Message System. We have used a variety of methods to gatherthis information: we have walked about public workstation clusters on campus and observed if,how, and how much users seem to be using the Andrew Message System. We have alsoconducted interviews with users, some of a series of informal questions we asked users as weobserved them. Other interviews have been more structured and planned. We ask user suchquestions as how often they send and receive mail, how many and which bboards they aresubscribed to, or what improvements would make Messages easier to use.

Another example of exploratory testing is a series of surveys (Haas & Zalevsky, 1988; Rago &Haas, 1987) which have been distributed at the end of each semester to the instructors whoteach new students on campus about Andrew. The Computer Skills Workshop, offered toincoming students at Carnegie Mellon, includes a six week introduction to the Andrew System.Each semester we submit a survey to the teaching assistants who instruct the course. Theprimary goal of the survey is to collect data about the level of Andrew mastery of the CSWstudents. The bulk of the survey is a series of Likert-scale questions which ask instructors toindicate the number of students in their classes who have achieved mastery with variousAndrew features; instructors chose from these responses: almost all, more than half, less thanhalf, or very few. In addition, we solicit opinions from the instructors about Andrew. Thesurvey asks Likert-scale and open-ended opinion questions about five aspects of the Andrewsystem, including the Andrew Message System.

The results of the most recent survey (conducted in October 1987) showed impressive levels ofuse and satisfaction for the Andrew Message System. Virtually all of the instructors surveyedindicated that more than half of their students were facile and comfortable with reading andsending mail and reading bulletin boards; almost 88% of the instructors indicated that almost allof their students had reached this level of competence after six weeks of instruction. Further, inan open-ended question on the survey which asked instructors to indicate Andrew features orprograms which they personally found useful or valuable, two-thirds volunteered the informationthat Messages was one of these useful programs. This level of satisfaction was higher forMessages than for any other Andrew feature or program. And finally--the most heartening resultfor those of us who have worked together to improve the Andrew Message System--wheninstructors were asked to list any positive changes or improvements that they had noticed inAndrew in the last year, three-quarters volunteered that they had noticed actual improvements inthe Andrew Message System.

While these results were encouraging, the survey also pointed out a potential problem for newusers in the Andrew Message System. We noticed that for the second year in a row instructorsindicated that students were less facile with posting to bulletin boards than they were with otherAndrew Message System functions. Specifically, 30% of the instructors indicated that less thanhalf of their students were able and comfortable posting messages to campus bulletin boards.In other words, the level of competence with posting to bulletin boards was substantiallylower than with the other Andrew Message System functions, reading mail, sending mail, andreading bulletin boards. We are currently conducting follow-up studies to find out more aboutthis puzzling result.

Issue-Driven Testing

In contrast to the exploratory testing, issue-driven testing is usually designed to answer specificquestions about features within the Andrew Message System. For example, developers of the

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Andrew Message System were interested in the most beneficial way to allocate screen spacewithin the Messages window. Specifically, two rival Message window layouts had beendeveloped which allocated space to the regions within Messages differently and arranged theregions within the window in two different ways. These two rival interfaces were generallyreferred to as the "stacked" interface (pictured in Figure 3), in which the three regions arearranged in a stack; and the "next-to" interface (Figure 4), in which the folders region was nextto the captions region (the message region remained in the same location). We designed aseries of studies which were driven by the question: "What is the more useful way to allocateand arrange space within the Andrew Message System window?" (Zalevsky, 1987).

Figure 11. "Rival" layouts for three regions in Messages.

Users new to the Andrew System were introduced to and trained in use of the Andrew MessageSystem. Users were introduced to both of the rival layout schemes, the "stacked" interfaceand the "next-to" interface. The order in which users were introduced to the contrasting layoutschemes was counter-balanced across subjects. On a subsequent day users performed a recalltask: they were asked to role-play teaching the Andrew Message System to another new userof the system. The researcher took notes and tape recorded subjects' recalls. Following thisrecall task, we interviewed the subjects about which layout scheme they preferred and why.Results of both the recall task and the discussions with users revealed that the only effects werefor order: subjects both preferred and recalled better the layout scheme they had learned first.That is, regardless of which layout scheme subjects learned first, that is the layout scheme theyliked and remembered best.

Developers used the information obtained in this study to determine that the layout scheme ofthe Messages window might best be determined by individual users. The "stacked" interfacewas chosen as the default for new users, but--by simply choosing from a menu of displayoptions--users can change the layout they see to the "next-to" interface. One of the mostimportant results of this study is that it underscores the importance of consistency within aninterface. Bearing in mind that users seem to become accustomed to and prefer systemfeatures with which they are familiar is at least as important as determining specific interfacefeatures.

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Conclusion

Interface design is crucial to the success of any computer system since, to the user, theinterface is the system. This design process, however, is as complex as it is important. Theuser interface of the Andrew Message System has benefited from the expertise of a range ofpeople with different background, training, and contributions, including graphic designers andhuman factors evaluators trained in cognitive psychology, education, and document design.With help from experts in a variety of domains, the AMS has become an impressive and widelyused showpiece of the Andrew system.

Acknowledgments

Responsible for the development of the AMS was the Message System Group at theInformation Technology Center: Jon Rosenberg, Nathaniel Borenstein, Craig Everhart, andAdam Stoller. Tracy Futhey, Director of Computing for the College of Humanities and SocialSciences (and John Stuckey in that position before her), supported collection of survey datafrom the instructors of the Computing Skills Workshop. Monica Zalevsky and Vincent Ragoassisted in the collection and analysis of the data from the surveys. Current ITC Director AlfredSpector and former ITC Director Jim Morris deserve thanks, as do members of the UserInterface Group: Andy Palay and Maria Wadlow.

References

Borenstein, N., Everhart, C., Rosenberg, J., & Stoller, A. (1988) A multi-media message systemfor Andrew. Proceedings of the USENIX Technical Conference, February.

Haas, C. & Zalevsky, M. (1988). Report on Survey of Computer SKills Workshop TeachingAssistants. Information Technology Center Occasional Paper.Howard, J. H. (1988) Anoverview of the Andrew File System. Proceedings of the USENIX Technical Conference,February.

Morris, J., Satyarayanan, M., Conner, M., Howard, J. H., Rosenthal, D., & Smith, F. D. (1986).Andrew: A distributed personal computing environment. Communications of the ACM, 29 (3),184-201.

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