A badly designed Web site interface can result in a site that is hard to find and hard to use but a well-designed interface helps users find and utilize the information they need quickly and easily. Explaining what interface design is and how to evaluate it, this guide explores the importance of interface design to users, reveals how a product gets designed, and provides a design evaluation template and design analyses of CD-ROMs, Web sites, and online providers.
|Publisher:||Information Today, Inc.|
|Sold by:||Barnes & Noble|
|File size:||1 MB|
About the Author
Alison J. Head is a lecturer, writer, and information management consultant. She has been a contractor on Internet design and evaluation at Hewlett-Packard and has lectured extensively on library and information science. She lives in Sonoma, California.
Read an Excerpt
A Guide for Evaluating the Interface Design of Information Resources
By Alison J. Head
Information Today, Inc.Copyright © 1999 Alison J. Head
All rights reserved.
Why Design Matters
It has happened more than once. I run across some souped-up Web version of one of my favorite information sources and, within seconds, I am sucked in. At last, all of that coveted information is compiled in one searchable multimedia extravaganza. With a slight tap to the keyboard, information comes pouring onto the screen like floodwaters from a Midwestern storm. I dive in with careless disregard: hook, line, and online registration. But after a few encounters, my enthusiasm dampens. The site is not all it is cracked up to be. The frenetic graphic that dances across the screen every time I pull up the site begins to annoy me. The circuitous layout wears me out. Searching is slow and frustrating. It does not take long. Less than three months later, I have pulled the site from my bookmark list. Another misbegotten venture in the online world.
Whatever system we are using — whether it is a CD or an online service or a Web site — most of us begin taking an interest in interface design (whether we call it that or not) when aspects of the interface stop working well for us. It is absolutely true that no one likes a slow, plodding CD-ROM. An online service glutted with overwhelmingly bright colors that draws our attention in ninety different directions can be tough to take, too. A Web site with undersized and incomprehensible icons is just plain unnavigable. When an interface becomes clunky, illogical, muddled, unintuitive, inflexible, obstinate, and circuitous — then interface design matters very much to us.
On the most basic level, design matters because it plays a large role in determining whether we can get our work done. A well-designed tool is one that is easy to interpret and satisfying to use. In fact, many software developers say that the best designs are ones that users never give a second thought about. They describe this quality as invisibility and it is the hallmark of effortless user interaction and good design. In contrast, a poorly designed tool is far from invisible, taking far too much time to use and delivering few results for our work in return. Whether an interface design is a good one or a poor one is a complex and involved issue. But one thing is certain for users, issues of design quality begin with a resource's interface.
What Exactly Is an Interface?
An interface is the visible piece of a system that a user sees or hears or touches. Users come into contact with an interface when they use a system, often needing to get a task done. Regardless of whether it whirs, spins, speaks, or lights up, an interface exists in one form or another in every system. There are millions of different interfaces that are designed by someone for something. Some interfaces work well for us, while others do not. Don Norman (who is interviewed at the end of this chapter) has written thoroughly and candidly about the interface design of computers, as well as that of commonplace devices. In The Design of Everyday Things, Norman even considers the interface of doorknobs. These common devices, depending on the visibility of their design, may reveal how a door works. A well-designed doorknob communicates to its users whether a door should be pushed or pulled. A poorly designed doorknob gives us no clues. When this happens, we must experiment until we figure out how the door works — sometimes to our own detriment! Norman's point is that well-designed interfaces, no matter what kind of mechanism we are talking about, are based on solid design principles that enhance use. A good design is a reliable and effective intermediary, sending us the right cues so that tasks get done — regardless of how trivial, incidental, or artful the design might seem to be.
Computer interfaces are also important translators of functionality. They work by projecting a simplified, designed version of all of the complex information-processing tasks actually occurring inside the box's circuitry, whether it is withdrawing money from an automated teller machine (ATM), word processing a letter, or viewing a video clip from a Web page. In order to carry out tasks, users type in something through a keyboard or they point and click with a mouse. This aspect of the exchange between a user and an interface is called interaction. Once a request has been entered by the user, the computer undergoes several translation stages. Translation occurs at the program level as well as at the circuitry level, funneling a response back to users through the interface. As involved as this electronic dance may seem, processing usually occurs very quickly, owing much to the speed and agility of the microprocessor chip.
ATMS: The Design of Everyday Banking
Several semesters ago, I taught an introductory seminar on Human-Computer Interaction (HCI) to advanced graduate students in information science. I used an assignment to find out what the untrained eye notices — good and bad — about interface design. During the first class, I gave a brief lecture on interface design. I then sent the students out to evaluate the design of a bank's ATM. For some, this sounded too hard for a first assignment. What did they possibly know about design? I gave them some basic guideline questions along with the assignment: Was the ATM usable? How easily did the system support the functions they use often and the ones they use rarely? What aspects of the ATM design were optimal and less than optimal? The following week the students returned with their field observations. Overall, they had mixed reviews about ATMs; some things worked well while others needed more design work. Among their observations:
A green light around the card entry slot on some ATMs drew their attention to an important starting point.
Commonly used functions, like withdrawing $40, appeared as first choices on menus, which made navigating a lot more direct and efficient.
Left-handed users had a tough time with ATMs because the input pad is designed for right-handed users.
There were hours during the day when the screen became unreadable because of intense glare from the sun shining on the screen.
Customizing options for operations that many students performed over and over again were non-existent.
It turned out after all that the students did know something about interface design. In fact, many of their observations were quite insightful. Among them, they found that it is reasonable to expect cues for first-time users. They anticipated quick responses from the system. When the screen sat mute after a button was pushed, their interaction with the ATM began to break down. The students' comments revealed an underlying dimension that is true for all user interactions with interfaces: No matter who we are, what system we are using, or what skill level we have mastered, we bring certain expectations to systems about completing some necessary task. When those expectations are not met, then the design begins to fail.
Interfaces and Design Language
In the past 20 years, most of us have come to know computer interfaces by what is being communicated to us through a unit's screen. The concept of design language describes how interfaces communicate what objects are to users, what they might do, and how they should be used. Just as spoken language is a basis of conversation between people, design language is a basis of communication between designers, users, and interfaces. While spoken language has grammar and words, design language consists of a more narrowly defined set of design elements (icons, for instance), the rules for their combination, and the context in which they exist. An interface design language has three primary parts. First, there are elements, (or the icons), color, and functions that appear on the screen. Second, there are organizing principles, an interface's grammar, which are the rules for how design elements will be combined to convey meaning. Third, there are qualifying principles, or design that takes into account the medium's context and its opportunities and limitations. The Web, for example, has many qualifying principles. On one hand, the Web medium has multimedia opportunities, while on the other, the Web is limited by external factors, such as variability among browsers.
As we saw in the ATM example, what is on the screen (icons, desktops, menus, or cursors) and how these artifacts can be manipulated (through a mouse or a keyboard) make up a system's interface and its design language. The menu that appeared on the ATM is an interface element that is featured in a variety of computer products as a method for navigation. The choice of functions that serve as headings and their layout on a menu are the organizing principles that communicate how the system can be manipulated and controlled by users. In the students' design commentary, they indicated that there are advantages and disadvantages to the ATM environment (such as the way sunlight minimized the readability of the screen during certain times of the day), which make up its qualifying principles. Interface designers and system developers have to choose between each one of these design language components and weigh the trade-offs. The choices that developers make and the impact that they may have on users and how users interact with a system is the basis of the study of Human-Computer Interaction (HCI).
Defining Human-Computer Interaction
Even though HCI is a relatively new field, it shares a long history with the design of artifacts for human use. In particular, HCI is concerned with creating interactive computer systems that are usable. Many of the early concepts in the HCI discipline originated in the late 1970s and 1980s. Ideas came to fruition by way of engineers' efforts at Xerox (and later, Apple and IBM) to build computer-based systems that were more user-centered than engineer-centered. As the field has taken hold, definitions of HCI have become multidisciplinary, technical, and diverse. Nevertheless, there are two general definitions of HCI that are widely agreed upon by practitioners in the field. The first one comes from the lead HCI association, The Curriculum Development Group of the Association for Computing Machinery (ACM) Special Interest Group on Computer-Human Interaction (SIGCHI):
Human-Computer Interaction is a discipline concerned with the design, evaluation, and implementation of interactive computing systems for human use and with the study of major phenomena surrounding them.
Another definition comes from a leading HCI textbook:
Human-Computer Interaction (or HCI) is, put simply, the study of people, computer technology, and the ways these influence each other. We study HCI to determine how we can make this computer technology usable by people.
As both definitions indicate, HCI has two primary dimensions. First, HCI has a dimension that is a practical method that involves user testing during the building and implementing of new systems. The second dimension of HCI is an evaluative study about cognitive and other behavioral factors that come into play when people interact with computers. Each one of these dimensions is interrelated and interdependent. In many cases, formal findings about how people interact with systems generated from the evaluation side of HCI become a basis for decision making about design trade-offs during product development.
Dimensions of HCI
In order to build user-centered systems, developers need to look at users' needs, values, and supportable tasks. This is why the HCI approach involves typical users who participate early on in testing of prototypes and other usability studies with product developers. Even before the actual design process begins, developers following an HCI approach first analyze a product's potential user base and how users are going to utilize the system in their jobs. To get at this information, developers simulate real work situations and prototypes with intended users. HCI researchers ask these five primary questions when building user-centered systems:
How will design work get done during the development phase?
How can systems be designed that work better to support users' tasks?
What design trade-offs exist and what are solutions that support users?
What can we make that is new?
Is the system usable?
Besides being a building methodology and technique, HCI is also an evaluative study about the interaction that occurs between people and computers. In the past 20 years, HCI research has been carried out to establish metrics and standards for creating user-centered design. When graphical user interfaces were just being developed, there were many unanswered questions about what rules to apply. HCI researchers played an important role in establishing many standards for predicting users' performance. One example of early empirical HCI research carried out at Xerox's Palo Alto Research Center (PARC) quantified the optimum speed of a mouse in relation to human processing speed. This study was one of the Human Processor Model Studies, groundbreaking work that paired engineering capabilities with human cognitive abilities so that more user-responsive systems could be built.
Much of HCI research pulls together seemingly disparate fields, such as engineering and cognitive science, to study interaction effects and to recommend design approaches. Yet the core of HCI evaluation is firmly grounded in four major disciplines: computer science, cognitive science, social psychology, and human factors or ergonomics. Each of these primary fields has made a significant contribution in defining the parameters of the HCI subfield.
Computer Science. Computer science delivers the device that creates a need for an interface. Computer science and HCI are deeply intertwined since HCI is actually a component of computer science. Computer science deals with the technological capabilities and the engineering components of computing systems and products, while HCI deals with translating system complexities into interfaces that support users' tasks and capabilities. HCI is chiefly concerned with creating user-centered interfaces that enhance user interactions, while computer science involves automating and processing symbolic information through algorithms. The combined fields have successfully led to automating dimensions of the design process of HCI, including the creation of high-level programming languages, new devices for interaction, and prototyping tools.
Cognitive Science. Cognitive science, a branch of psychology, is the study of how the human behaviors of perception, attention, learning, and memory affect information processing. Cognitive theory plays a seminal role in HCI because it analyzes how people figure out and communicate with computing systems. Many early HCI-based cognitive studies have focused on how people perceive computer systems, especially studying how users go about problem-solving in a computer environment, how their attention is managed, and how users learn and retain operational information over time. Cognitive fundamentals and principles, many of which were developed in the 1980s, have provided much of the early HCI framework.
Social Psychology. Social psychology is the scientific study of how humans behave as groups in social and work settings. HCI work, with a social psychology focus, combines group issues such as organizational structures, power, and authority with HCI issues of how information flows among groups, shared technology, and social contexts. A growing amount of HCI research is rooted in this framework, especially as networked tools like e-mail, groupware, and virtual reality applications have become more commonplace.
Human Factors. Human factors deal with matching the physical characteristics of systems with users' capabilities and capacities. In particular, human factors studies are concerned with training, performance, and behavior and ways to improve the design practicalities of safety and efficiency. Recent human factors research has concentrated on screen readability rates, repetitive stress syndrome and the building of safer systems, and developing emerging interaction styles like voice activation.
HCI as Process
The HCI process deals with creating more usable systems for people and their work settings. Much of the underlying purpose of HCI incorporates good design, both in practice and in understanding. To achieve this goal, HCI is the study of both sides of the interaction experience. By this we mean that HCI addresses what occurs on the human side of interaction as well as what happens on the machine side. Basically, HCI looks at human processing abilities and communication structures that occur between users and their computers. HCI also uncovers methods for mapping computing functions to human capabilities and effectively using input and output techniques so that computers and users have more seamless interactions.
When the SIGCHI chapter of the ACM was in its infancy, the group developed a graphic (shown in Figure 1.1) that illustrates the boundaries of HCI and the interrelationships between the two sides of interaction, the human side and the machine side. The bottom of the graphic shows another dimension of HCI, which deals with how systems are built. HCI puts a special emphasis on creating and applying user-centered design techniques as well as using iterative usability testing methods.
The Relevance of HCI
In recent years, many disciplines have contributed to forming and expanding HCI thought. These disciplines include linguistics, artificial intelligence, anthropology, epistemology, communication, sociology, and graphic design. As a result, HCI has grown as a field and gathered increased support on college campuses, in information technology companies, and among professional computing organizations. The reason for the growing interest in HCI may be long overdue: Fundamentally, HCI is a study that embraces everyday users while making a strong case for developing workable systems for them.
Another way HCI has gained ground is by developing elegant and new solutions that actually transform how people interact with systems. One such development is direct manipulation and the mouse. Direct manipulation is now a commonplace interaction style that allows users to move objects around a computer screen with a mouse, as they would a real object. For users to be able to physically move objects on a screen was an early programming breakthrough for the fledgling HCI field — one that presented point-and-click ease and control of the graphical user interface to a huge number of novice users.
Excerpted from Design Wise by Alison J. Head. Copyright © 1999 Alison J. Head. Excerpted by permission of Information Today, Inc..
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.
Table of Contents
List of Figures and Tables,
Part 1 Interface Design Basics,
Chapter 1 Why Design Matters,
Chapter 2 Secret Shame,
Chapter 3 Deconstructing Evaluation,
Part 2 Interface Design Analyses,
Chapter 4 CD-ROMs: Treasure Trove or Wasteland?,
Chapter 5 Web Sites: Weaving Deceit?,
Chapter 6 Online Commercial Databases: Power Tools Unplugged?,
Chapter 7 Four Predictions,