8/2/2019 hci intrnl

1/11

1)Provide Effective Feedback and Guidance and Assistance. Effectivefeedback and guidance and assistance are also necessary elements ofgood design. This step presents the guidelines for presenting to the userfeedback concerning the system and its processing status. It also describesthe system response times necessary to meet user needs. Step 9 alsodescribes the kinds of guidance and assistance that should be included in asystem, and presents important design guidelines for the various kinds.Create Meaningful Graphics, Icons, and Images. Graphics, including iconsand images, are an integral part of design. Design guidelines for varioustypes of graphics are presented. Icons are described, including adiscussion of what kinds of icons exist, what influences their usability, andhow they should be designed so they are meaningful and recognizable.The elements of multimedia presentation are also reviewed. Guidelines

presented include those for images, photographs, videos, drawings,animation, and audition.

8/2/2019 hci intrnl

2/11

2)What is aprototype?When you hear the term prototype, you may imagine something like a scalemodel of a building or a bridge, or maybe a piece of software that crashesevery few minutes. But a prototype can also be a paper-based outline of ascreen or set of screens, an electronic "picture," a video simulation of atask, a three-dimensional paper and cardboard mockup of a wholeworkstation, or a simple stack of hyperlinked screen shots, among otherthings.

A prototype is an early sample or model built to test a concept or processor to act as a thing to be replicated or learned from.

In fact, a prototype can be anything from a paper-based storyboard through

to a complex piece of software, and from a cardboard mockup to a moldedor pressed piece of metal. A prototype allows stakeholders to interact withan envisioned product, to gain some experience of using it in a realisticsetting, and to explore imagined uses.For example, when the idea for the Palmpilot was being developed, JeffHawkin (founder of the company) carved up a piece of wood about the sizeand shape of the device he had imagined. He used to carry this piece ofwood around with him and pretend to enter information into it, just to seewhat it would be like to own such a device (Bergman and Haitani, 2000).This is an example of a very simple (some might even say bizarre)prototype, but it served its purpose of simulating scenarios of use.So a prototype is a limited representation of a design that allows users tointeract with it and to explore its suitability.

8/2/2019 hci intrnl

3/11

3)An approach is to apply theories and conceptual frameworks to interactiondesign. In this we examine three of these approaches, which each have adifferent perspective on cognition: mental models, information processing,external cognitionMental modelsA successful system is one based on a conceptual model that enablesusers to readily learn a system and use it effectively. What happens whenpeople are learning and using a system is that they develop knowledge ofhow to use the system and, to a lesser extent, how the system works?These two kinds of knowledge are often referred to as a user's mentalmodel.Mental models are also used to fathom what to do when somethingunexpected happens with a system and when encountering unfamiliarsystems. The more someone learns about a system and how it functions,

the more their mental model develops.

Information processingAnother approach to conceptualizing how the mind works has been to usemetaphors and analogies. A number of comparisons have been made,including conceptualizing the mind as a reservoir, a telephone network, anda digital computer.The information processing model provides a basis fromwhich to make predictions about human performance. The informationprocessing approach is based on modeling mental activities that happenexclusivelyinside the head.

8/2/2019 hci intrnl

4/11

External cognitionPeople interact with or create information through using a variety ofexternal representations, e.g., books, multimedia, newspapers, web pages,maps, diagrams, notes, drawings, and so on.The combinationof externalrepresentations and physical tools have greatly extended and supportedpeople's ability to carry out cognitive activities. External cognition isconcerned with explaining the cognitive processes involved when weinteract with different external representations. Amain goal is to explicatethe cognitive benefits of using different representations for different

cognitive activities and the processes involved. The main ones include:1. Externalizing to reduce memory loadAnumber of strategies have been developed for transforming knowledgeinto external representations to reduce memory load. One such strategy isexternalizing things we find difficult to remember, such as birthdays,appointments, and addresses.

2. Computational offloadingComputational offloading occurs when we use a tool or device inconjunction with an external representation to help us carry out acomputation.

3. Annotating and cognitive tracingAnother way in which we externalize our cognition is by modifyingrepresentations to reflect changes that are taking place that we wish tomark.These two kinds of modification are called annotating and cognitivetracing:Annotating involves modifying external representations, such as crossingoff or underlining items.Cognitive tracinginvolves externally manipulating items into different ordersor structures.

8/2/2019 hci intrnl

5/11

4)Social mechanisms in communication and collaborationA fundamental aspect of everyday life is talking, during which we pass onknowledge to each other. We continuously update each other about news,changes, and developments on a given project, activity, person, or event.The kinds of knowledge that are circulated in different social circles arediverse, varying among social groups and across cultures. The frequencywith which knowledge is disseminated is also highly variable. It can happencontinuously throughout the day, once a day, weekly or infrequently. Themeans by which communication happens is also flexible.Below we describe three main categories of social mechanisms andexplore how technological systems have been and can be designed tofacilitate these:

the use of conversational mechanisms to facilitate the flow of talk and

help overcome breakdowns during it the use of coordination mechanisms to allow people to work and interact

together

the use of awareness mechanisms to find out what is happening, whatothers are doing and, conversely, to let others know what is happening

Conversational mechanismsTalking is something that is effortless and comes naturally to most people.And yet holding a conversation is a highly skilled collaborativeachievement, having many of the qualities of a musical ensemble. Below

we examine what makes up a conversation. We begin by examining whathappens at the beginning:A: Hi there.B: Hi!C: Hi.A: All right?C: Good. How's it going?A: Fine, how are you?C: Good.B: OK. How's life treating you?

Who are famous for their work on conversation analysis-describe these interms of three basic rules:Rule 1-the current speaker chooses the next speaker by asking an opinion,question, or requestRule 2-another person decides to start speakingRule 3-the current speaker continues talking

8/2/2019 hci intrnl

6/11

Coordination mechanismsCoordination takes place when a group of people act or interact together toachieve something. For example, consider what is involved in playing agame of basketball. Teams have to work out how to play with each otherand to plan a set of tactics that they think will outwit the other team. For thegame to proceed both teams need to follow (and sometimes contravene)the rules of the game. An incredible amount of coordination is requiredwithin a team and between the competing teams in order to play.In particular, we need to figure out how to interact with one another toprogress with our various activities. To help us we use a number ofcoordinating mechanisms. Primarily, these include:

verbal and non-verbal communication

schedules, rules and conventions

shared external representations

Verbal and non-verbal communicationWhen people are working closely together they talk to each other, issuingcommands and letting others know how they are progressing with theirpart. For example, when two or more people are collaborating together, asin moving a piano, they shout to each other commands like "Down a bit, lefta bit, now straight forward" to coordinate their actions with each other. As ina conversation, nods, shakes, winks, glances, and hand-raising are alsoused in combination with such coordination "talk" to emphasize andsometimes replace it.

Schedules, rules, and conventionsA common practice in organizations is to use various kinds of schedules toorganize the people who are part of it. For example, consider how auniversity manages to coordinate the people within it with its availableresources. A core task is allocating the thousands of lectures and seminarsthat need to be run each week with the substantially smaller number ofrooms available. A schedule has to be devised that allows students toattend the lectures and seminars for their given courses, taking intoaccount numerous rules and constraints. These include:

A student cannot attend more than one lecture at a given time.

A professor cannot give more than one lecture or seminar at a giventime.

A room cannot be allocated to more than one seminar or lecture at agiven time.

Only a certain number of students can be placed in a room,depending on its size.

8/2/2019 hci intrnl

7/11

Shared external representationsShared external representations are commonly used to coordinate people.We have already mentioned one example that of shared calendars thatappear on user's monitors as graphical charts, email reminders, and dialogboxes. Other kinds that are commonly used include forms, checklists, andtables. These are presented on public notice boards or as part of othershared spaces. They can also be attached to documents and folders. Theyfunction by providing external information of who is working on what, when,where, when a piece of work is supposed to be finished, and who it goes tonext.

Awareness mechanismsAwareness involves knowing who is around, what is happening, and who istalking with whom (Dourish and Bly, 1992). For example, when we are at a

party, we move around the physical space, observing what is going on andwho is talking to whom, eavesdropping on others' conversations andpassing on gossip to others. A specific kind of awareness is peripheralawareness. This refers to a person's ability to maintain and constantlyupdate a sense of what is going on in the physical and social context,through keeping an eye on what is happening in the periphery of theirvision. This might include noting whether people are in a good or bad moodby the way they are talking, how fast the drink and food is being consumed,who has entered or left the room, how long someone has been absent, andwhether the lonely guy in the corner is finally talking to someone-all whilewe are having a conversation with someone else. The combination of directobservations and peripheral monitoring keeps people informed andupdated of what is happening in the world.Similar ways of becoming aware and keeping aware take place in othercontexts, such as a place of study or work. Importantly, this requiresfathoming when is an appropriate time to interact with others to get andpass information on. Seeing a professor slam the office door signals tostudents that this is definitely not a good time to ask for an extension on anassignment deadline. Conversely, seeing teachers with beaming faces,

chatting openly to other students suggests they are in a good mood andtherefore this would be a good time to ask them if it would be all right tomiss next week's seminar because of an important family engagement. Theknowledge that someone is amenable or not rapidly spreads through acompany, school, or other institution. People are very eager to pass onboth good and bad news to others and will go out of their way to gossip,

8/2/2019 hci intrnl

8/11

loitering in corridors, hanging around at the photocopier and coffeemachine "spreading the word."In addition to monitoring the behaviors of others, people will organize theirwork and physical environment to enable it to be successfully monitored byothers. This ranges from the use of subtle cues to more blatant ones.

8/2/2019 hci intrnl

9/11

5)Identifying usability and user experience goals is essential for making everyproduct successful, and this requires understanding users' needs. The roleof evaluation is to make sure that this understanding occurs during all thestages of the product's development.What, why, and when to evaluateUsers want systems that are easy to learn and to use as well as effective,efficient, safe, and satisfying. Being entertaining, attractive, andchallenging, etc. is also essential for some products. So, knowing what toevaluate, why it is important, and when to evaluate are key skills forinteraction designers.What to evaluateThere is a huge variety of interactive products with a vast array of featuresthat need to be evaluated. Some features, such as the sequence of links to

be followed to find an item on a website, are often best evaluated in alaboratory, since such a setting allows the evaluators to control what theywant to investigate.Why you need to evaluateJust as designers shouldn't assume that everyone is like them, they alsoshouldn't presume that following design guidelines guarantees goodusability, Evaluation is needed to check that users can use the product andlike it. Furthermore, nowadays users look for much more than just a usablesystem.When to evaluateThe product being developed may be a brand-new product or an upgradeof an existing product. If the product is new, then considerable time isusually invested in market research. Designers often support this processby developing mockups of the potential product that are used to elicitreactions from potential users. As well as helping to assess market need,this activity contributes to understanding users' needs and earlyrequirements.Evaluations done during design to check that the product continues to meetusers' needs are known as formative evaluations. Evaluations that are

done to assess the success of a finished product, such as those to satisfy asponsoring agency or to check that a standard is being upheld, are knowas summative evaluation.

Some practical issues that evaluators routinely have to address include:

what to do when there are not many users

8/2/2019 hci intrnl

10/11

how to observe users in their natural location (i.e., field studies)without disturbing them

having appropriate equipment available

dealing with short schedules and low budgets

not disturbing users or causing them duress or doing anythingunethical

collecting "useful" data and being able to analyze it

selecting techniques that match the evaluators' expertise

Evaluation paradigms are related to a particular discipline in that theystrongly influence how people from the discipline think about evaluation.Each paradigm has particular methods and techniques associated with it.We identify four core evaluation paradigms: (1) "quick and dirty"evaluations; (2) usability testing; (3) field studies; and (4) predictiveevaluation."Quick and dirty" evaluation A "quick and dirty" evaluation is a commonpractice in which designers informally get feedback from users orconsultants to confirm that their ideas are in line with users' needs and areliked. "Quick and dirty" evaluations can be done at any stage and theemphasis is on fast input rather than carefully documented findings.Usability testing involves measuring typical users' performance oncarefully prepared tasks that are typical of those for which the system wasdesigned. Users' performance is generally measured in terms of number of

errors and time to complete the task.Field studiesThe distinguishing feature of field studies is that they are done in naturalsettings with the aim of increasing understanding about what users donaturally and how technology impacts them. In product design, field studiescan be used to (1) help identify opportunities for new technology; (2)determine requirements for design; (3) facilitate the introduction oftechnology; and (4) evaluate technologyPredictive evaluation I In predictive evaluations experts apply theirknowledge of typical users, often guided by heuristics, to predict usabilityproblems. Another approach involves theoretically based models. The keyfeature of predictive evaluation is that users need not be present, whichmakes the process quick, relatively inexpensive, and thus attractive tocompanies; but it has limitations.

8/2/2019 hci intrnl

11/11

TechniquesThere are many evaluation techniques and they can be categorized invarious ways, but in this text we will examine techniques for: observingusers asking users their opinions asking experts their opinions testingusers' performance modeling users' task performance to predict theefficacy of a user interface.Observing usersObservation techniques help to identify needs leading to new types ofproducts and help to evaluate prototypes. Notes, audio, video, andinteraction logs are well-known ways of recording observations and eachhas benefits and drawbacks. Obvious challenges for evaluators are how toobserve without disturbing the people being observed and how to analyzethe data, particularly when large quantities of video data are collected orwhen several different types must be integrated to tell the story

Asking usersAsking users what they think of a product-whether it does what they want;whether they like it; whether the aesthetic design appeals; whether theyhad problems using it; whether they want to use it again-is an obvious wayof getting feedback. Interviews and questionnaires are the main techniquesfor doing this.Asking expertsSoftware inspections and reviews are long established techniques forevaluating software code and structure. Developers like this approachbecause it is usually relatively inexpensive and quick to perform comparedwith laboratory and field evaluations that involve users. In addition, expertsfrequently suggest solutions to problems.User testingMeasuring user performance to compare two or more designs has been thebedrock of usability testing. Data is collected so that performance can beanalyzed. Generally the time taken to complete a task, the number of errorsmade, and the navigation path through the product are recorded.Descriptive statistical measures such as means and standard deviationsare commonly used to report the results.

Modeling users' task performanceThere have been various attempts to model human-computer interaction soas to predict the efficiency and problems associated with different designsat an early stage without building elaborate prototypes. These techniquesare successful for systems with limited functionality such as telephonesystems.