106CR- Design for Usability

The Economic case

A case for usability that allows businesses to profit monetarily from good interface design.

The Legal and Ethical case

A case for usability that suggests that poor accessibility and usability is simply not polite. This relates to discrimination laws in real life that prevents those with disabilities to be 'locked out' of a shop due to accessibility (eg. wheelchair ramps)

The Competitive case

A case for usability that suggests that rival sites and businesses are just a few clicks away online and that a negative usability experience means the loss of an individual customer forever.

Semantic bridging

A design gulf should do this so the person understands what to do and what has happened.

Physical bridging

A design gulf should do this so the personal can physically or perceptually find out what to do or what has happened.

Prototype

A full-scale working model used to test a design concept by making actual observations and necessary adjustments.

Design inertia

A large problem with prototypes. This means early bad decisions stay bad. The time investment in a prototype produces a desire to 'stay with it' even if it exhibits problems.

Validity limitation

A limitation with usability test data. Are the conditions under which the data was recorded reproducible?

Reliability limitation

A limitation with usability test data. Can you count on the data to be representative of the audience? If the users aren't typical of the true audience or significant individuals vary within the test group, there can be issues.

Task Analysis

A method to analyse human actions: -What people do. -What things they work with. -What they must know. This is completed by observing a task, collecting unstructured lists of words and actions and organising using notation or diagrams. AIMS: -Describe thee actions people do. -Structure them within task/sub task hierarchy. -Describe the order of subtasks.

Usability test

A procedure that critically examines the actual performance of a user involved in a communication process. The procedures are conducted with end users, ideally in their own environments, while performing real tasks. They reveal any problems faced.

How to design better

A question from the visual design lecture. Three main points to complete this are: -Know that you can -Read and learn -Practice

Graphical centred design

A set of questions on usability primarily concerned with the aesthetic design of the hardware/software and look and feel. How do I create a good looking site? What can I create from the available tools? How do I as a graphic designer think the system should be designed?

System centered design

A set of questions on usability primarily concerned with the technical design of the hardware/software and functionality. What can I build on this platform? What can I create from the available tools? How do I as a programmer think the system should be designed?

User centred design

A set of questions on usability primarily concerned with those who will use the hardware/software. What do users want to do with this software? How can I make this software easier to use? How do I make the software usable by the widest number of people?

The CIF Framework

A template for a summative usability test report.

Effectiveness

A term used to describe an interface. Can you actually do a specific task? Measuring technique: % of tasks completed

Efficiency

A term used to describe an interface. Can you do it quickly, without getting bored or frustrated? Measuring technique: time

Learnability

A term used to describe an interface. Can you use it without constantly reaching for the manual or asking for help.

Satisfaction

A term used to describe an interface. Is it fun, or at least pleasant to use? Measuring technique: rating in a questionnaire

Discretionary

A type of HTA plan where subtasks are completed in an arbitrary order.

Mixtures

A type of HTA plan where tasks are a combination of multiple plans.

Time-sharing

A type of HTA plan where tasks are completed at the same time.

Fixed sequence

A type of HTA plan where tasks are explicitly ordered one after the other.

Optional tasks

A type of HTA plan where tasks are not essential to the process and may only need to be completed on occasion.

Cycles

A type of HTA plan where tasks are repeated until a condition is met.

Wait for events

A type of HTA plan where tasks rely on an exterior occasion to occur before it is completed itself.

Hierarchical

A type of navigational structure that involves navigation through a series of levels. This structure implies a ranking of different levels of ideas- a movement form the general, to the specific. User has more choice with this structure.

Web-type

A type of navigational structure where items are linked in a circular or looping fashion.

Linear

A type of navigational structure where one page follows the next. Useful if users aren't experts and limits their control as well as if information has to be presented in a particular order.

Open ended web structure

A type of very common web type structure that can be fairly complicated to navigate but often features a home button.

Closed web structure

A type of web type structure where all pages connect to all others. There is a freedom within limits. In a very complex web, users can become lost.

Navigational structure

An (often obvious) internal structure that a system possesses that allows it to be organised and traversed. These can include things like: -Historical sequence -Real world task order -Theme or topic -Size or scale -Geographical location

Intangible IO

An input or output for a system that isn't typed or uses a screen. (eg. Output for a thermostat is the controlling of the temperature)

Form fill

An interaction style most popular for web interactions. Features include: -Fields to collect info. -Drop down menus to limit choice. -Radio buttons to limit choices. -Check boxes to select multiple options.

Direct manipulation

An interaction style that behaves as though the interaction was with a real world object rather than with an abstract system. The feeling of working directly on the task. Central ideas include: - Visibility of the objects of interest. -Rapid, reversible actions. -Manipulation by pointing and moving. -Immediate and continuous display of results. (eg. Wii sports (motion control), painting on Photoshop/Paint etc.)

Wizards

An interaction style that takes the user linearly step by step through a process. Complex tasks are broken into understandable chunks. It is a good way of mapping between the user's task steps and the system's task steps but can be frustrating and time consuming if only a subtask is to be completed.

Verb/object (command line)

An interaction style where the user chooses an action, then selects an object to perform the action upon. This interfaces emphasises the actions rather than the nouns. ADVANTAGE- Close to human language. DISADVANTAGE- Actions and not visible and are abstract.

Object/verb (WIMP style)

An interaction style where the user chooses an object and then the action that is to be performed on it. This interface emphasises the nouns rather than the actions. ADVANTAGES- -Closer to real world manipulation. -Actions are always within the context of the object- inappropriate ones can be hidden. -Generic commands can be applied to multiple objects (eg. drag and drop on files, folders, paragraph, numbers) -Flexibility. Multiple ways to do the same thing. DISADVANTAGES- -Not very powerful and batch actions are harder to do. Repetitive.

Application GUI's

An interface design world for operating systems. These use published standards and often feature visual design techniques and development toolkits that include interface builders.

Device interfaces

An interface design world that entails designing for things like mobile phones, MP3 players, cookers etc. Perhaps the most challenging due to the diverse nature of the 'world'. Good design patterns are adopted and used a multitude of times.

Web interfaces

An interface design world where standards are proposed by the W3C but are often ignored due to accessibility. Good design of these interfaces rely on heuristics and successful patterns. A highly creative and innovative platform but open to being chaotic, amateurish and disastrous.

Task decomposition

An iterative process of breaking the description of a system down into finer and finer detail.

Globalisation

Broadening the device market across the planet.

Contrast repetition alignment proximity

CRAP- An acronym used in visual design.

Localisation

Culturally specific interfaces, especially web (eg. Amazon .com, .co.uk, .de, .au etc.

Interoperability

Growing expectations that devices will work together.

Accelerators

Navigational shortcuts used to speed up the process of locating information suggested by Schneiderman.

Constraints on Implementing usability

One approach to understanding the importance of usability. Made up of design inertia, traditions and legal, contractual and process holdbacks which limit the implementation of new or revolutionary usability.

The case for usability

One approach to understanding the importance of usability. Made up of three sub cases, these make up the incredible importance of usability to businesses.

The paradigm shift

One approach to understanding the importance of usability. The change in design focus from fitting the user to the interface to fitting the interface to the user. Also, the change of users themselves from technical experts to novice users.

Good-continuation

One of Gestalt's laws. Given a juncture of lines, the viewer sees as continuous those lines that are smoothly connected.

Closure

One of Gestalt's laws. If a set of stimuli almost encloses an area or could be interpreted as enclosing an area, the viewer sees the area.

Proximity

One of Gestalt's laws. Two visual stimuli that are close to each other are seen as belonging together.

Similarity

One of Gestalt's laws. Two visual stimuli that have a common property are seen as belonging together.

User testing

One of the fastest ways of 'debugging' forms design.

Style

One of the twelve principles of good human-centred interactive systems design. -ACCOMMODATION Designs should be attractive and contextually suitable.

Conviviality

One of the twelve principles of good human-centred interactive systems design. -ACCOMMODATION Making systems polite, friendly and generally pleasant to interact with.

Flexibility

One of the twelve principles of good human-centred interactive systems design. -ACCOMMODATION The ability of being able to do the same action a multiple of different ways. Supports a broader range of users- the novice and experts.

Control

One of the twelve principles of good human-centred interactive systems design. -EASE OF USE Making it clear who or what is in charge. Logical mapping between controls and the effect they have enhances this principle.

Navigation

One of the twelve principles of good human-centred interactive systems design. -EASE OF USE Providing support to enable people to move around a system with maps, directional signs etc. Menus are a good example and often used to do this.

Feedback

One of the twelve principles of good human-centred interactive systems design. -EASE OF USE Rapidly giving people information back from the system so they know what effect their actions have had.

Affordance

One of the twelve principles of good human-centred interactive systems design. -LEARNABILITY. Designing things so it is clear what they are for. This also refers to the properties that things have. (eg. chairs having the affordance of sitting)

Visibility

One of the twelve principles of good human-centred interactive systems design. -LEARNABILITY. Ensuring elements and widgets are legible to the users and obvious what functions are available and what the system is doing.

Consistency

One of the twelve principles of good human-centred interactive systems design. -LEARNABILITY. This involves maintaining a standard and pattern both internally to the system and externally as the system relates to outputs.

Familiarity

One of the twelve principles of good human-centred interactive systems design. -LEARNABILITY. Using language and symbols that the intended audience will recognise and immediately recall their knowledge and understanding of similar systems.

Recovery

One of the twelve principles of good human-centred interactive systems design. -ROBUSTNESS Enabling the bounce back from actions, particularly mistakes and errors, quickly and effectively.

Constraints

One of the twelve principles of good human-centred interactive systems design. -ROBUSTNESS Making sure people do not try to do inappropriate things for the good of the user and the system. A security and error prevention technique.

Personalisation

The customisability and preferences setting that users expect from their devices.

Usability

The extent to which a product can be used by specified users to achieve specified goals with effectiveness, efficiency and satisfaction in a specified content of use.

Jeff Hawkins

The inventor of the Palm Pilot (a personal digital assistant). This guy carried around a small block of wood around in his shirt pocket and when needed, would pretend and imagine how he would use the device.

Gestalt

The name of the school for psychologists. Came up with the principles of visual perception and how the brain and stimuli and the resulting judgments about the world.

Gestalt's Laws

The principles that explain how users make judgement about what is related and what is unrelated, based on virtual cues.

User Interface

The site of interaction between people and technology. Any visible interface accessible by the user. This is the part of a system that allows the user to: -Interact with the technology -Input commands -Get feedback -Carry out tasks

Usable

The term used instead of 'user friendly' to describe an interface. To use this term requires that we measure 'usability' with some predetermined metrics/measures.

Interaction style

The type or design of a user interface system. Examples include: - Verb/object (command line) - Object/verb (WIMP style) - Direct manipulation - Form fill -Wizards

Design principles

These 'guidelines' are based on knowledge from many fields, especially psychology, graphic design, cultural studies. Abstract guidelines may be applicable during early design activities but detailed style guides will be needed at later points.

Design standards

These are like 'rules' with/set by high authority. Specific to a particular type of design set by (inter)national bodies to ensure compliance by a large community of designers. Sometimes these are enforced for safety reasons and failure to apply these can lead to disaster.

Heuristics and Guidelines

These turn general guidelines into a practical example in a particular design domain. These are often a useful checklist for good design.

Gulf of Evaluation

This design gulf is concerned with deciding whether the actions were successful in moving the person towards his or her goal.

Gulf of Execution

This design gulf is concerned with translating goals into actions.

Limited functionality simulations

This prototype can be used to user test properties of the interface (eg. forms can be tested to make sure they are usable)

Storyboard

This prototype features a series of drawings used to illustrate the sequence of action or outline of a concept.

Flowcharts

This prototype provides a map of the information architecture, often characterised by processes and decisions.

Throw away prototype

This prototype uses a rough version to answer a design question.

Incremental prototype

This prototype uses the first prototype as the basic for the second.

Action oriented research

Usability research concerned with not WHY an interface fails but WHAT can be changed to make it work. - Field observation -Engagement with users -Prototype building