The Principle of Least Astonishment, in shorthand, encompasses what we, as designers, must achieve to ensure consistency in our designs. Consistency is a fundamental design principle for usable user interfaces. But the thing that astonishes me is that it’s actually necessary to explain this principle. Surprise implies the unexpected. Of course, users want the response to a given action to be what they expect; otherwise, they would have done something else. In user interactions, the unexpected is pretty much the same as the unwanted. Surprise usually implies something bad rather than something positive—unless users already have such dismally low expectations of their software that they might think, Wow! It worked. I’m so astonished.
One of the most common implementations of menu views has been the “side drawer,” “basement,” or “side menu” made popular in apps such as Facebook and Path. When a user taps the “Hamburger” icon to open a side menu, the main screen slides to the right (or left in some implementations) to reveal another screen below.
The concept of an affordance was coined by the perceptual psychologist James J. Gibson in his seminal book The Ecological Approach to Visual Perception. The concept was introduced to the HCI community by Donald Norman in his book The Psychology of Everyday Things from 1988. There has however been ambiguity in Norman's use of the concept, and the concept thus requires a more elaborate explanation.
User interface standards can be hard to use for developers. In a laboratory experiment, 26 students achieved only 71% compliance with a two page standard; many violations were due to influence from previous experience with non-standard systems. In a study of a real company's standard,developers were only able to find 4 of 12 deviations in a sample system, and three real products broke between 32% and 55% of the mandatory rules in the standard. Designers were found to rely heavily on the examples in the standard and their experience with other user interfaces.
What if something neither looks nor quacks like a duck, but users think it is a duck? The cranky user comments on baby duck syndrome and how it can trap users with systems and interfaces that don't really meet their needs.
This study investigates the breakdown of the psychomotor components of three different input devices, the mouse, trackball, and RollerMouse™ using the Stochastic Optimized Submovement Model. Primary movement time (PMT), Total Movement Time (TMT), Primary Movement Distance (PMD), and Total Movement Distance (TMD) were examined for each device. Results showed that psychomotor variables related to the primary phase of movement help to pinpoint how performance efficiency is affected by a particular device. For example, the relationship between %PMD and efficiency suggests that a device that affords users an initial accurate movement decreases the need for more or longer corrective submovements, thus reducing movement time.
Many usability problems are instances of what we call 'conceptual gaps.' A conceptual gap arises because of some difference between the user’s mental model of the application and how the application actually works.If the gap is large enough, it can stop the user’s work. For example, a user who wants to search the web for free local concerts may not know how to formulate a query that will yield this information. The gap between the search engine’s syntax and the user’s understanding of that syntax may prevent the user from accomplishing their goal.
Population aging and environmental concern are two important factors that will effect the design of vehicles in the future. In response to the potential conflict between them, the authors propose a shift in focus from individual vehicles to transport services, from '€˜A Car for All'€™ to '€˜Mobility for All'€™, and offer strategies, scenarios and case studies of how this might be achieved. New service and vehicle typologies are introduced and discussed, and an area of future research and development is identified.
Jared Spool goes out of his way to position himself as anything but a user-interface designer. Yet through his company, User Interface Engineering (UIE), he is a frequent keynote speaker on effective Web design, produces a monthly publication reviewing Web sites for effectiveness, and runs a series of workshops of effective Web design. Founded in 1988, UIE is an independent research, training, and consulting firm specializing in user-interface design and product usability issues. It has grown into one of the United States' leading usability research practices, conducting more than 400 usability tests each year on software and Web sites.
Sometimes we can’t take away the number of options we’re asking the user to choose from. But we can try and solve for the best possible outcome. By giving the user a means to drill down their choices, or offering up a “Best Value” or “Popular Choice” we help minimize cognitive dissonance thus giving them a richer user experience.
We present a public usability study that provides preliminary results on the effectiveness of a universally designed system that conveys music and other sounds into tactile sensations. The system was displayed at a public science museum as part of a larger multimedia exhibit aimed at presenting a youths’ perspective on global warming and the environment. We compare two approaches to gathering user feedback about the system in a study that we conducted to assess user responses to the inclusion of a tactile display within the larger audio-visual exhibit; in one version, a human researcher administered the study and in the other version a touch screen computer was used to obtain responses. Both approaches were used to explore the public’s basic understanding of the tactile display within the context of the larger exhibit.
A common mandate at many software companies is “Make our products consistent!” I’ve heard this clarion call for consistency at every company I’ve worked for that has more than a single product or service. The rationale behind the consistency mandate is that it will reduce design and development costs, improve the overall quality of the software, strengthen the brand (“the products should all look like they come from the same company”), make learning easier for users, and reduce errors when multiple products are used together. These are all great goals, but there is a problem with the consistency mandate – consistency is complex, multi-dimensional, and sometimes at odds with other important goals like usability.
Most businesses have seen a dramatic increase in the amount of information employees require to perform tasks. Traditional approaches to training such as paper documentation, instructor-led training, or computer-based training (CBT) may have been effective in the past, but are not suitable to respond to the rapid changes in time, cost, and delivery of information today’s marketplace requires. At Unisys Corporation we have piloted an electronic performance support system that provides self-instruction for our clients at their point of need.
Designing a user interface using minimalist principles for guided exploration can reduce the amount of paper and text necessary to document the system. Graphics in the interface can help the user grasp the concepts of the system, while dialog boxes, status information, and error messages can aid in recognition of success and recovery from errors. Online help can then be used as a backup for users if they get stuck. Reducing text and paper can reduce translation and printing costs, making this process very attractive.
This article discusses turn signals and how they are used. Turn signals improve safety because they give people time to react and they reduce driving ambiguity. However, they are only effective when people actually use them. Several lessons are applied to web usability.
Beyond just the undeniable importance of a usable form and voting mechanism, is the need to consider the comfort and satisfaction of voters dealing with sometimes radically changed voting systems, especially when the move is from paper-based voting systems to electronic systems.
A usability assessment entailing a paper prototype was conducted to examine menu selection theories on a small screen device by determining the effectiveness, efficiency, and user satisfaction of a popular cellular phone's menu system. Outcomes of this study suggest that users prefer a less extensive menu structure on a small screen device. The investigation also covered factors of category classification and item labeling influencing user performance in menu selection. Research findings suggest that proper modifications in these areas could significantly enhance the system's usability and demonstrate the validity of paper-prototyping which is capable of detecting significant differences in usability measures among various model designs.
First person user interfaces can be a good fit for applications that allow people to navigate the real world, “augment” their immediate surroundings with relevant information, and interact with objects or people directly around them.
This study reports a psychophysical comparison of four ergonomic mouse-type devices to the standard mouse. It was hypothesized that muscle activity transferred from the distal to proximal limbs for some of the ergonomic mice may result in increased load on the shoulders and declines in target acquisition performance. Results revealed a potential tradeoff between performance and safety with the devices as participants performed the best with the standard mouse but reported more wrist exertion with this device.
In the world of usability, Thomas Gilbert, human performance engineer; John Bowie, information engineer; and Genichi Taguchi, quality engineer, are singing a three-part harmony. Exemplifying different generations as well as three distinct but overlapping domains, these experts converge at a vantage point from which they should be jointly capable of conducting the whole orchestra. This article explains the contributions each individual has made, directly or indirectly, to the domain of software development.
Technical communicators who work as members of software development teams often act as user advocates. Part of this role includes working with developers to design screens that allow users to easily use the software and understand the information presented. This two-part workshop presents various exercies and handouts which help attendees develop an easy-to-use and understand interface for users.