Usability - Chapter 1

usability is broken down in the following goals:

- effective to use (EFFECTIVENESS) - efficient to use (EFFICIENCY) - safe to use (SAFETY) - having good utility (UTILITY) - easy to learn (LEARNABILITY) - easy to remember how to use (MEMORABILITY) **usability goals are typically operationalized as questions - purpose is to provide the interaction designer with a concrete means of assessing various aspects of an interactive product and the user experience)

e.g of design principles

-- products should be designed to provide adequate feedback to the users to ensure they know what to do next in their tasks -- findability - the degree to which a particular object is easy to discover or locate be it navigating a website, moving through a building, or finding the delete image option on a digital camera

wide range of disabilities including:

1. color-blindness (this has an impact on the use of color for highlighting or distinguishing interface elements) 2. dyslexia (the contrast between foreground and background text or images) 3. physical impairments (tremor, shaking, weakness, pain, reduced control of limbs, inability to sit upright, to short or missing limbs)

The process of interaction design involves four basic activities:

1. establishing REQUIREMENTS 2. designing ALTERNATIVES 3. PROTOTYPING 4. EVALUATING **these activities are intended to inform one another and to be repeated**

Evaluating - ways to achieve user input:

1. observing users 2. talking to them 3. interviewing them 4. modeling their performance 5. questionnaire 6. asking them to become co-designers

2 kinds of afforfance

1. perceived (screen based interfaces) 2. real (physical objects)

To make interactive products safer involves:

1. preventing the user from making serious errors by reducing the risk of wrong keys/buttons being mistakingly activated (not putting quit or delete so close to save command on a menu) 2. providing users with various means of recovery should they make mistakes

people are considered to be disabled if:

1. they have a mental or physical impairment 2. the impairment has as adverse effect on their ability to carry out normal day to day activities 3, the adverse effect is substantial and long term (lasted more than 12 months or is likely to last for more than 12 months or for the rest of their lives)

Things to take into account when designing interactive products:

1. usability 2. functionality 3. aesthetics 4. content 5. look and feel 6. sensual & emotional appeal

T/F: one can design a user experience

FALSE - one cannot design a user experience, only design for a user experience. one cannot design a sensual experience, but only create the design features that can evoke it (eg. designing a sleek, smooth, silky phone case will evoke a sensual and satisfying user experience) (heavy and awkward = poor user experience that is uncomfortable and unpleasant)

T/F: old people want things to be big - be it text or graphical elements appearing on screen or the physical controls, like dials and switches used to control devices.

FALSE - studies have shown that many people in their 70s , 80s, and older are perfectly capable of interacting with standard-size information and even small interfaces (e.g. cell phones). Being aware of people's sensitivities is as important as knowing how to design for their capabilities.

T/F: It is very realistic for interaction designers to take all of these factors (and many others) into account and be able to translate and combine them to produce quality user experience.

FALSE - there is no magic formula to help them. As of yet there isn't a unifying theory or framework that can be readily applied by interaction designers. BUT there are numerous conceptual frameworks, tried and tested design methods, guidelines, and relevant research findings.

the user experience

How a product behaves and used by people in the real world

the importance of understanding of people in the contexts in which the live, work, and learn:

How people interact with one another, their abilities, emotions, needs, desires, and what causes them to get annoyed, frustrated, lose patience, and get bored will help designers understand how to design interactive products that will fit those niches. It also helps designers appreciate that one size does not fit all. Can also reveal incorrect assumptions that designers may have about particular user groups and what they need.

the user experience described by Garrett

It is about how people FEEL about a product and their PLEASURE and SATISFACTION when using it, looking at it, holding it, opening or closing it. Includes their OVERALL IMPRESSION of how good it is to use, the sensual effect small details have on them such as how smoothly a switch rotates or the sound of a click and the touch of a button when pressing it.

the concept of flow

a state of intense emotional involvement that comes from being completely involved in an activity, like playing music, and where time flies, and completely absorbed. (popular in the design of user experiences for websites, video games, and other interactive products)

EFFECTIVENESS

a very general goal and refers to how good a product is at doing what it is SUPPOSED to do. QUESTION: is the product capable of allowing people to learn, carry out their work efficiently, access the information they need, or buy the goods they want?

cultural identity

age, ethnicity, race, disability, family status, occupation, education.

affordance 'to give a clue'

an attribute of an object that allows people to know how to use it. e.g. a mouse button invites pushing by the way it is physically constrained in a plastic shell. its easy how to interact with it. icons = clicking scrollbars = moving up and down buttons = to afford pushing

user experience goals (short def)

being concerned with explicating the nature of the user experience (e.g. to be aesthetically pleasing) *stress the importance of considering usability goals AND user experience goals together when designing for a user experience

usability goals (short def)

being concerned with meeting specific usability criteria (e.g. efficiency) *stress the importance of considering usability goals AND user experience goals together when designing for a user experience

what is another important concern for interaction design besides being aware of people's sensitivities?

cultural differences - particularly for products intended for a diverse range of user groups from different countries. there are standard differences in the way cultures communicate and represent information by using different form factors, images, and graphical elements, colors, types of images, structuring of information to appeal to people in different countries.

consistency

designing interfaces to have similar operations and use similar elements for achieving similar tasks. e.g. always click the left button to highlight something. benefits of consistent interfaces is that they are easier to learn and use. users have to learn only a single mode of operations that is applicable to all objects. works well for simple interfaces with limited operations (e.g portable radio). not ideal for more complex interfaces especially when many different operations need to be designed for. introducing inconsistency can make it more difficult to learn an interface but in the long run can make it easier to use (think KNIVES)

Other wide-reaching aspects stressed by Carroll:

fun, health, social capital, cultural identity

MEMORABILITY

how easy a product is to remember how to use, once learned. especially important for interactive products that are used infrequently. QUESTION: what kind of interface support have been provided to help users remember how to carry out tasks? especially for products and operations they use infrequently?

LEARNABILITY

how easy a system is to learn to use (especially so for interactive products intended for everyday use) 60% said they stopped using an application if they could not get it working straight away while 95% would try more new services if the technology was easier to set up. QUESTION: is it possible for the user to work out how to use the product by exploring the interface and trying out certain actions? how hard will it be to learn the whole set of functions in this way?

SAFETY

involves protecting the user from dangerous conditions and undesirable situations. QUESTION: what is the range of error that are possible using the product and what measures are there to permit users to recover easily from them?

feedback

involves sending back information about what action has been one and what has been accomplished, allowing the person to continue with the activity. various kinds of feedback are available for interaction design - audio, tactile, verbal, visual, and combinations of these. using feedback in the right way can also provide the necessary visibility for user interaction.

constraints

refers to determining ways of restricting the kinds of user interaction that can take place at a give moment. (e.g. a menu showing restricted availability of options) one of the advantages of this form of constraining is that it prevents the user from selecting incorrect options and thereby reduces the chance of making a mistake. the physical design of a device can also constrain how it is used - e.g. the external slots in a computer have been designed to only allow a cable to be inserted in a certain way.

usability

refers to ensuring tat interactive products are easy to learn, effective to use, and enjoyable from the user's perspective. it involves optimizing the interactions people have with interactive products to enable them to carry out their activities at work, school and in their every day lives.

Accessibility

the degree to which an interactive product is accessible by as many people as possible. A focus is on people with disabilities. the challenge is to create a good user experience for people with disabilities that is both accessible and usable.

quantitative indicators of usability criteria

the extent to which productivity has increased, or how work, training, or learning have been improved. They are useful for measuring the extent to which personal, public, and home-based products support leisure and information-gathering activities. BUT DO NOT address the overall QUALITY of the user experience which is where user experience goals come into play.

UTILITY

the extent to which the product provides the right kind of functionality so that users can do what they need or want to do (e.g. of high utility is an account software package that provides a powerful computational tool that accountants can use to work out tax returns and e.g. of low utility a software drawing tool that does not allow users to draw freehand but forces them to use a mouse to create drawings using only polygon shapes) QUESTION: does the product provide an appropriate set of functions that will enable users to carry out all their tasks in the way they want to do them?

Evaluating

the heart of interaction design. it's focus is on ensuring that the product is APPROPRIATE. usually addressed through a user-centered approach to design and seeks to involve users throughout the design process.

on a more subjective level of user experience:

the importance of people's EXPECTATIONS and the way they make sense of their experiences when using technology.

visibility

the more visible functions are, the more likely it is that users will be able to know what to do next.

most important aspect of the user experience

the quality of the experience someone has, be it a quick one (such as topping up a cell phone), a leisurely one (such as playing an interactive toy), or an integrated one (such as visiting a museum).

social capital

the social resources that develop and are maintained through social networks, shared values, goals and norms.

EFFICIENCY

the way a product supports users in carrying out their tasks (e.g. Amazon one click option) QUESTION: once users have learned how to use a product to carry out their tasks, an they sustain a high level of productivity

usability criteria

these are specific objectives that enable the usability of a product to be assessed in terms of how it can improve (or not) a user's performance. examples of commonly used usability criteria are time to complete a task (EFFICIENCY), time to learn a task (LEARNABILITY), and the number of errors made when carrying out a given task over time (MEMORABILITY).

user experience goals

these are subjective qualities and are concerned with how a system feels to a user. they are concerned with how users experience an interactive product from their perspective, rather than assessing how useful or productive a system is from its own perspective. they offer subtly different options for expressing the way an experience varies for the same activity over time, technology, and place. the process of selecting terms that best convey a user's feelings, state of being, emotions, sensations, and so forth when using or interacting with a product at a given time and place and help designers understand the multifaceted and changing nature of the user experience. user experience concepts are most useful when turned into specific questions.

what design principle is NOT intended to do

they are not intended to specify how to design an actual interface e.g. telling the designer how to design a particular icon or how to structure a web portal, but act more like triggers to designers, ensuring that they have provided certain features at an interface.

elements that contribute to making a user experience pleasurable, fun, exciting, etc.

they include attention, pace, play, interactivity, conscious and unconscious control, style of narrative, and flow.

design principles

used by interaction designers to aid their thinking when designing for the user experience. intended to orient designers toward thinking about different aspects of their design. design principle is derived from a mix of theory-based knowledge, experience, and common sense. the dos and don'ts of interaction design and intended to help designers explain and improve their designs.

most common design principles

visibility, feedback, constraints, consistency, and affordance.