Issue
Article
Vol.29 No.1, January 1997
Article
Issue
Issue |
Article |
Vol.29 No.1, January 1997 |
Article |
Issue |
It is fair to say that the most extensive activity in human-computer interaction standards is currently happening in the International Organization for Standardization (ISO), and, specifically, in the Ergonomics technical committee (TC159). The purpose of this work is to help manufacturers of office automation systems produce more usable systems, thus enhancing the health, safety, satisfaction, and productivity of workers, to encourage some level of consistency among office systems, and to help purchasers of office systems make decisions among suppliers.
In this column I will cover the status of work on standards for user interface design of computer software and multimedia in ISO TC159. Next time, I will discuss the work stemming directly from this activity which has started in the U.S. by ANSI and the Human Factors and Ergonomics Society.
More than half a decade ago Subcommittee 4 (SC4) of TC159 began work on a multipart ergonomic and human-computer interaction standard for office work on visual display terminals (VDTs). This is ISO 9241. The second half of this suite of standards, Parts 10-17, pertain to the design of software displayed on VDTs. Each of these parts is being drafted and edited on an independent schedule, thus, some sections may become standards at different times, even though all the sections are interrelated. However, at this point, nearly all the parts are in the final stages of approval.
Table 1: ISO 9241 (Parts 10-17): Status as of 3Q96
---------------------------------------- Part Subtitle Status ---------------------------------------- 10 Dialogue Principles IS 11 Guidance on Usability DIS 12 Presentation of Information CD 13 User Guidance DIS 14 Menu Dialogues DIS 15 Command Dialogues DIS 16 Direct Manipulation Dialogues DIS 17 Form-filling Dialogues DIS ----------------------------------------
ISO rules define a four stage process in the development of standards (ISO/IEC, 1992). The first step is the production of a Working Draft (WD), often produced outside of committee by one editor or a small group. (By convention, the person responsible for the major writing and editing of a standards document is referred to as the "editor" and never as the "author" -- even when, in some cases, there is a single person who is the author of a document.) The WD may go through a series of revisions and additions until it is ready to be voted upon. At some point, the WD is ready to be circulated to the whole ISO sub-committee, at which point the document becomes a Committee Draft (CD). When the sub-committee believes the document is ready, the CD is circulated to national representative bodies for a vote. The national bodies vote on progressing the CD to the next stage, a Draft International Standard (DIS). Often these votes involve technical comments from different national bodies. Rejection at this level means further revision on the CD, which can then be brought up for vote multiple times, until it passes. At the DIS stage, the document can then circulate to the national bodies for vote on progression of the standard to the final stage, an International Standard (IS). With ISO 9241, drafts have sometimes been repeatedly brought up for vote, revised, and brought up for vote again at the DIS level. A new step has entered the process, a "final-DIS" vote, where national bodies are instructed to vote yes or no without any comments, as a final approval for release as a "real" standard. The current status of the human-computer interaction parts of 9241 is given in Table 1.
ISO 9241 is collectively titled "Ergonomic requirements for office work with visual display terminals (VDTs)", but, as shown in the table, each part has a descriptive subtitle. That's certainly not enough, so let's look in somewhat more detail at each Part.
This section sets forth some general principles of human-computer interaction which can be applied as guidelines for developing any application or dialogs within an application. Indeed, Part 10 is seen as a framework for deriving the more specific recommendations which appear in the remaining software sections of 9241. This document does not contain any requirements or recommendations. The generic dialog principles are:
This section also contains no specific requirements or recommendations, but, instead, it explains the concept of usability and how to identify the information needed to specify and evaluate the usability of software systems. This section emphasizes that usability is dependent upon the "context of use", that the usability of a piece of software is influenced by the specific tasks, users, hardware, physical and social work environment, etc. In some sense, this section is a counterbalance to Parts 12-17, which offer specific recommendations which are universal to software systems.
This part provides recommendations on the organization and coding of visual information as it is presented on display screens. Among the topics addressed are grouping of information, lists and tables, labels and fields, cursors, fields, abbreviations, visual coding of information (including coding by colors and graphics), and requirements for multiple windowing systems.
More than merely on-line help systems, user guidance here is defined as any information beyond the regular task dialog that is provided to the user on request, or is automatically provided by the system. Guidance aids users in achieving desired results, i.e. in using or understanding the system in order to complete their tasks. Specially, this section provides recommendations for the design of different classes of on-line help systems, feedback information, error management (messages and dialogs associated with errors and malfunctions). It does not cover on-line tutorials or on-line manuals.
Part 14 provides recommendations for the design of menus used in user-computer dialogs. Menus are lists of selectable options, and thus this section covers such dialog elements as pull-down menus, pop-up menus, full-screen menus, panels, buttons, fields, lists, and other similar techniques. The section covers menu structure, grouping and sequencing of menu items and groups of menus, menu navigation, methods or selecting and executing options in menus, and menu presentation.
Table 2: ISO 14915: Multimedia User Interface Design Ergonomic Requirements for Human-Computer Multimedia Interfaces: Status as of 3Q96
--------------------------------------------------
Part Subtitle Status
--------------------------------------------------
1 Introduction and Framework WD
2 General Design Issues for
Multimedia Controls and Navigation WD
3 Media Combination and Specific
Multimedia Requirements for
Individual Media WD
4 Domain Specific Multimedia Aspects No draft
--------------------------------------------------
Command dialogs are defined as sequences of instructions given by the user to the software system which result in system actions. The key here is that user inputs are syntactically structured commands and/or abbreviations which the user must recall from memory. Besides the typical command language dialog with which we are all familiar, Part 15 also covers commands which may be elements of graphical user interfaces, and also it covers function keys and command hot keys. It does not cover icons, menus, forms, or other elements which, although they may be related to commands, are recognized and not recalled by the user.
Direct manipulation is a dialog technique where the user directly acts upon objects or object representations on a display screen by pointing at them, moving them, or changing their physical characteristics, by the use of a input device (such as a mouse, trackball, joystick, etc.). The recommendations for user interface design in this section are on topics such as when to use direct manipulation as a technique, metaphors, appearance of objects, feedback, input devices, pointing and selecting, dragging, sizing, scaling, rotating, manipulation of text objects, and manipulation of windows. Note that this section covers the user input aspect of windowing systems whereas Part 12 covers the visual presentation aspect.
Part 17 provides recommendations on the design of computer displayed forms, both graphic and text-based. In addition, the design of dialog boxes in graphical user interfaces are covered (as a sub-species of forms). Included are sections on forms layout, field and label length and alignment, input into form fields, form-related menus, buttons, controls, and form navigation.
Recently, ISO TC159/ SC4 has committed to a new work item on multimedia user interface standards. All parts of this standards are currently in the extremely early stages of initial drafts and outlines. The current composition and titles of the parts of this standards are presented in Table 2. At this stage, it is not unlikely that outlines, structure, content, and titles in this document will change considerably.
Currently, Part 1 of 14915 is a general introduction which provides an overview and background information on multimedia, but no requirements or recommendations. Part 2 will provide recommendations for the design of multimedia controls and navigation (e.g. audio controls, functions such as play, stop, pause, scan etc.) and Part 3 will provide recommendations on specific media and media combinations. Part 4 may cover specific domains such as computer based training, computer supported cooperative work, kiosks, and other topics.
Although only some of the various parts of ISO 9241 have become ISO International Standards, we are already beginning to see various strategies for using this document to evaluate software. Recently, I have discovered the work of Willumeit, Gediga, & Hamborg (1996a, b) at the University of Osnabrück in Germany on a usability inventory they call IsoMetrics. This questionnaire assesses usability according to seven dialog principles set forth in Part 10 of ISO 9241 (see above). IsoMetrics was constructed from 151 items derived from existing usability inventories in the general literature. Each item was assigned to one of the seven principles of ISO 9241 Part 10 (excluding 61 items which could not be assigned to a principle). The resulting questions were given 5-point rating scales and validated with 229 subjects. The IsoMetrics inventory can thus rate a software system on each of the seven principles, and, in this sense, can assess "conformity" to Part 10. (In addition, a variation on the questionnaire can be used to elicit user comments as well and used in the iterative design process.)
Up to date descriptions and status of the various software sections of ISO 9241 and ISO 14915 will be found at the IBM Human-Computer Interaction Site, at the URL http://www.ibm.com/ibm/hci/on the World Wide Web. On the IBM HCI page you will also find coverage of other standards bodies concerned with human-computer interaction.
Thanks to Ken Holdaway, Scott Issensee, Eric Bergman, and Günther Gediga for contributing information used in this column.
Opinions expressed in this column are not necessarily those of AT&T, ACM, or SIGCHI.
Please contribute information, corrections, and thoughts to this column by sending Internet email to heb@acm.org, or call my office at +1 908 949-9745, or fax +1 908 949-8569.
ISO/IEC (1992). ISO/IEC Directives part 1: Procedures for the technical work. 2nd Ed. (Available for order from ANSI at +1 212 642-4600.)
Willumeit, H., Gediga, G., & Hamborg K-C. (1996a). The IsoMetrics usability inventory: An operationalization of ISO 9241/10. Unpublished manuscript. University of Osnabrück, Germany. (available on the World Wide Web at
http://www.psycho.uni-osnabrueck.de/ggediga/www/isometr3.htm)
Willumeit, H., Gediga, G., & Hamborg K-C. (1996b). IsoMetrics: Ein Verfahren zur formativen Evaluation von Software nach ISO 9241/10, Ergonomie & Informatik, 27, 5-12.
Issue |
Article |
Vol.29 No.1, January 1997 |
Article |
Issue |