Chapter+Three


 * Chapter 3

Introduction** · **Access** concerns removing the barriers that would otherwise exclude some people using the system at all. · **Usability** refers to the quality of the interaction in terms of parameters such as time taken to perform tasks, numbers of errors made and the time to become a competent user (it may meet requirements of usability criteria, but may fail to satisfy audiences) · **Acceptability** refers to fitness for purpose in the context of use. · **Engagement** concerns designing for great, exciting and riveting experiences (aka ‘wow’ factor)

· Everyone should be able to have access to information that is delivered through software technologies · With an increasingly wide range of computer users and technologies, designers need to focus on the demands their designs make on peoples’ abilities · The sorts of issues that an ordinary user faces in an extraordinary environment (stress, time pressure) often are similar to the issues that extraordinary users (people with disabilities) in ordinary environments · Reasons why people can be excluded from accessing interactive systems include: o They way a piece of equipment is set up (ie. An ATM machine is too high for someone who is in a wheelchair) o They may not understand how to use a piece of equipment (ie. Instructions are far too complicated) o Financially someone may be excluded because of affordability issues o Cultural exclusion occurs when designers assume they know how everyone around the world lead their lives (ie. Slogans/terms that may be common in Canada, may not be common in China) o Social exclusion occurs when equipment may not be available at appropriate times or places. · Two main approaches to designing for accessibility: o Design for all (universal design) is based on four premises: § Varying ability is not a special condition of the few, but a common characteristic of being human and we change physically and intellectually throughout our lives § If the design meets the needs to the disabled, it can be used by everyone § At any point in our lives, personal self-esteem, identity and well-being are deeply affected by our ability to function in our physical surroundings with a sense of comfort, independence and control § Usability and aesthetics are mutually compatible o Inclusive design (says total inclusion is unattainable) As a way of ensuring an accessible system, designers should: § Include people with special needs in requirements analysis and testing of existing systems § Consider whether new features affect users with special needs (positively or negatively) and note this in the specification § Take account of guidelines, include evaluation against guidelines § Include special needs users in usability testing and beta tests o There are a lot of technologies that do cater to all audiences § the aim is to design to cater for the widest range of human abilities
 * Accessibility**

· systems should be easy to use, easy to learn, flexible and engender a good attitude in people · the goal is concerned with efficiency and effectiveness of systems · A system with high degree of usability: o It will be efficient in that people will be able to do things using an appropriate amount of effort o It will be effective in that it contains the appropriate functions and information content, organized in an appropriate manner o It will be easy to learn how to do things and remember how to do them after a while o It will be safe to operate in the variety of contexts in which it will be used o It will have high utility in that it does the things that people want to get done · 3 principles that Gould and Lewis use to meet usability: o Early focus on users and tasks (ie. Who the users will be, studying the expected work that would be accomplished, making users part of design team) o Empirical measurement (recording users reactions/reviews to the design developed) o Iterative design (problems in design are found and fixed, cycle of design, redesign, trials and error) o 4th principle: all usability factors must evolve together, and responsibility for all aspects of usability should be under on control · Another way to look at usability is to see it as concerned with achieving balance between the four principal factors of human-centered interactive system design, PACT o People o Activities people want to undertake o Contexts in which the interaction takes place o Technologies (hardware and software) · Important features of human-computer interaction (two relationships that need to be optimized) o The interaction between people and the technologies they are using (user interface) o Interaction between the people and technologies considered as a whole (the people-technology system), the activities being undertaken, and the contexts of those activities · Norman focuses on the interface between people and technology (the difficulty of turning goals into actions required by a user interface) o People have goals (devices typically only deal with simple actions- two gulfs must be bridged) o The gulf of execution- translating goals into actions. The gulf of evaluation- deciding whether the actions were successful in moving the person towards his of her goal o The gulfs need to be bridged semantically (do they know what to do/what has happened) and physically (can the person physically or perceptually find out what to do or what has happened) · Key issue of usability is that often technology gets in the way of people and the activities they want to do (we are conscious of bridging the gulfs) · Another key issue is to try to engender an accurate mental model of the system. A good design will have adopted a clear and well structured conceptual design that can be easily communicated to people
 * Usability**

· Fitting technologies into people’s lives. Key features: o **Political**- new technologies have been introduced for simple economic reasons, regardless of what people may feel about them and the ways that people’s jobs and lives might change. o **Convenience**- Designs should not be awkward and should fit effortlessly into any situation. o **Cultural and social habits**- designs should not be ‘rude’ or disturb users. It has to do with the way people like to live (ie. Spam mail is unacceptable) o **Usefulness**- goes beyond efficiency and effectiveness and concerns usefulness in context (ie. Diary function on PDAs are usable, but not sufficiently useful for everyday living) o **Economic**- Price and value for people’s money. It goes further than that- it may completely change how companies conduct business and make their money. § Norman characterizes situation for a successful technology as a stool with three legs: user experience, marketing and technology
 * Acceptability**

· Qualities of an experience that really pull people in. Engagement is concerned with all the qualities of the interactive experience that make it memorable, satisfying, enjoyable and rewarding. · If usability is concerned with optimizing the PACT elements in some domain, then engagement is when the elements are truly harmonized. · Key features: o **Identity**- Authenticity- if you are engaged in some experience and something happens that suddenly reminds you that it is not real, then the authenticity of the experience can be lost. Identifying with a key element of engagement (are you a PC or Mac?) o **Adaptivity**- is to do with change and personalization with changing levels of difficulty, pace and movement. Engagement is not about making things easy, but enjoying them o **Narrative**- is to do with telling a good story, with convincing characteristics, plot and suspense. o **Immersion**- is the feeling of being wholly involved within something, with being taken over and transported somewhere else. Immersion is not about the medium, but about the quality of design o **Flow**- is the sense of smooth movement, the gradual change from one stage to another · A medium is engaging if it draws the person in, if it seems to surround the activity, if it stimulates the imagination. · Computer games are a good example of how it can be engaging. A feeling of immersion, the need for a good story line, the authenticity of the game play and identification with characters, the different levels accommodating different abilities and the gradual smooth change of scenes: the flow.
 * Engagement**


 * Design Principles**
 * Design principles can guide the designer during the design process can be used to evaluate and critique prototype design ideas
 * Systems should be learnable, effective and accommodating
 * Designing interactive systems from a human-centered perspective is concerned with the following
 * Helping people access, learn and remember the system:
 * Visibility- let people see what functions are available and what the system is currently doing. If it is not visible, make it observable. People should be able to recognize things instead of having to recall them.
 * Consistency- conceptual and physical consistency is important. (being consistent with design features, ways of working etc.)
 * Familiarity- Use language and symbols people are familiar with
 * Affordance- design things so it is clear what they are (ie. Make buttons look like buttons). It refers to the properties things have and how these relate to how the things could be used


 * Giving them the sense of being in control, knowing what to do and how to do it
 * Navigation- provide support to enable people to move around the parts of the system: maps, directional signs and information signs
 * Control-make it clear who or what is in control and allow people to take control. (it is the most efficient if there is clear, logical mapping between controls and the effect they have)
 * Feedback- Fast feed back information from the system to people so that they know what effect their actions have had. (constant and consistent feed back will enhance the feeling of control)
 * Recovery- Enable recovery from actions, particularly mistakes and errors, quickly and effectively
 * Constraints- provide constraints so people do not do things they are inappropriate.
 * In a way that suits them:
 * Flexibility- allow multiple ways of doing things so as to accommodate users with different levels of experience and interest in the systems
 * Style- designs should be attractive and stylish
 * Conviviality- interactive systems should be polite, friendly and generally pleasant


 * Designing for Windows Applications**
 * All the above principles apply to designing for windows.


 * Design principles and website**
 * Navigation- enables people to discover structure and content of the site and to find their way to a particular part of the site.
 * Top banner- lets people know where they are, through clear and obvious labelling
 * Navigation bar- down the left-hand side tells people where thy can go (also lets people know where they have been)
 * The design principles are also implemented along with these features while designing a website
 * These principles also apply to mobile phones and ubiquitous computing


 * Overall**
 * Access to interactive systems for all people is an important right
 * Usability is concerned with balancing the PACT elements in a domain
 * Engagement aims to harmonize the PACT elements
 * Interactive systems design is different contexts and on different technological platforms