UNIT1 Usability of Interactive Systems 1 Usability of

UNIT-1 Usability of Interactive Systems 1

Usability of Interactive Systems Topics 1. Introduction 2. Usability Goals and Measures 3. Usability Motivations 4. Goals for Our Profession 1 -2

Introduction �The Interdisciplinary Design Science of Human Computer Interaction (HCI) combines knowledge and methods associated with professionals including: �Psychologists (incl. Experimental, Educational, Social and Industrial Psychologists) �Computer Scientists �Instructional and Graphic Designers �Technical Writers �Human Factors and Ergonomics Experts �User experience designers �Anthropologists and Sociologists 1 -3

Introduction (continued) �Individual User Level �Routine processes: tax return preparation �Decision support: a doctor’s diagnosis and treatment �Education and training: encyclopedias, drill and practice exercises, simulations �Leisure: music and sports information �User generated content: social networking web sites, photo and video share sites, user communities �Internet enabled devices and communication 1 -4

Introduction (continued) �Communities �Business use: financial planning, publishing applications �Industries and professions: web resources for journals, and career opportunities �Family use: entertainment, games and communication �Globalization: language and culture 1 -5

Introduction (continued) �Smart phones have high quality displays, provide fast Internet connections, include many sensors and support a huge variety of applications 1 -6

Introduction (continued) �Apple® Mac OS X® showing Picasa for photo browsing and Google Map in a web browser � The bottom of the screen also shows the Dock, a menu of frequently accessed items whose icons grow larger on mouse over 1 -7

Introduction (continued) �Ben Shneiderman at a standing desk with two high resolution screens. � The displays include a MS Word document (with six pages visible), two web browsers and the Outlook email application in a Windows environment. 1 -8

Introduction (continued) �The Amazon. com web site (http: //www. amazon. com/) showing the books published by Jen Golbeck � Facebook will make book and product recommendations based on a user’s personal history with the site 1 -9

Introduction (continued) �You. Tube showing a video showing NASA TV, and other available related videos on the side � The NASA video shows an example of control center with multiple large wall displays and workstations 1 -10

Introduction (continued) �Two children learn about the human body using a wearable, e textile shirt displaying real time visualizations of how the body working via “organs” with embedded LED lights and sound 1 -11

Introduction (concluded) �The HIPMUNK travel search shows available flights visually as seen on a Apple i. Pad tablet � The slider at the top allows users to narrow down the results, e. g. here we see only the flights landing before 10: 25 pm 1 -12

Book overview �Chapter 1: � A broad overview of human computer interaction from practitioner and research perspectives �Chapter 2: � Universal usability �Chapter 3: � Guidelines, principles, and theories �Chapters 4 6: � Managing design processes, evaluating designs, and case studies �Chapters 7 11: � Interaction styles, devices, communication and collaboration �Chapters 12 16: � Critical design issues, search and visualization �Afterword: � Societal and individual impacts of user interfaces 1 -13

Usability Goals and Measures � Successful designers: � Go beyond vague notions of “user friendliness”, “intuitive”, and “natural” doing more than simply making checklists of subjective guidelines � Have a thor ough understanding of the diverse community of users and the tasks that must be accomplished � Study evidence based guidelines and pursue the research literature when necessary � US Web Design Standards 1 -14

Usability Goals and Measures (continued) � Great designers: � Are deeply committed to enhancing the user experience, which strengthens their resolve when they face difficult choices, time pressures, and tight budgets � Are aware of the importance of eliciting emotional responses, attracting attention with animations, and playfully surprising users 1 -15

Usability Goals and Measures (continued) � Ascertain the user’s needs � Determine what tasks and subtasks must be carried out � � � Include tasks which are only performed occasionally Common tasks are easy to identify Functionality must match need or else users will reject or underutilize the product 1 -16

Usability Goals and Measures (continued) � Ensure reliability � Actions must function as specified � Database data displayed must reflect the actual database � Appease the user's sense of mistrust � The system should be available as often as possible � The system must not introduce errors � Ensure the user's privacy and data security by protecting against unwarranted access, destruction of data, and malicious tampering 1 -17

Usability Goals and Measures (continued) � Promote standardization, integration, consistency, and portability � � � Standardization: use pre existing industry standards where they exist to aid learning and avoid errors (e. g. the W 3 C and ISO standards) Integration: the product should be able to run across different software tools and packages (e. g. Unix) Consistency: � � compatibility across different product versions compatibility with related paper and other non computer based systems use common action sequences, terms, units, colors, etc. within the program Portability: allow for the user to convert data across multiple software and hardware environments 1 -18

Usability Goals and Measures (continued) � Define the target user community and class of tasks associated with the interface � Communities evolve and change (e. g. the interface to information services for the U. S. Library of Congress) � 5 human factors central to community evaluation: � Time to learn How long does it take for typical members of the community to learn relevant task? � Speed of performance How long does it take to perform relevant benchmarks? � Rate of errors by users How many and what kinds of errors are made during benchmark tasks? � Retention over time Frequency of use and ease of learning help make for better user retention � Subjective satisfaction Allow for user feedback via interviews, free form comments and satisfaction scales 1 -19

Usability Goals and Measures (concluded) �Trade offs in design options frequently occur �Changes to the interface in a new version may create consistency problems with the previous version, but the changes may improve the interface in other ways or introduce new needed functionality �Design alternatives can be evaluated by designers and users via mockups or high fidelity prototypes �The basic tradeoff is getting feedback early and perhaps less expensively in the development process versus having a more authentic interface evaluated 1 -20

Usability motivations Many interfaces are poorly designed and this is true across domains: �Life critical systems �Air traffic control, nuclear reactors, power utilities, police and fire dispatch systems, medical equipment �High costs, reliability, and effectiveness are expected �Lengthy training periods are acceptable despite the financial cost to provide error free performance and avoid the low frequency but high cost errors �Subject satisfaction is less an issue due to well motivated users 1 -21

Usability motivations (continued) Example life critical application: The Wand timeline view of a patient record in Allscript’s ambulatory Electronic Health Record i. Pad application 1 -22

Usability motivations (continued) � Industrial and commercial uses � Banking, insurance, order entry, inventory � � management, reservation, billing, and point of sales systems Ease of learning is important to reduce training costs Speed and error rates are relative to cost Speed of performance is important because of the number of transactions Subjective satisfaction is fairly important to limit operator burnout 1 -23

Usability motivations (continued) � Office, home, and entertainment applications � � � Word processing, electronic mail, computer conferencing, and video game systems, educational packages, search engines, mobile device, etc. Ease of learning, low error rates, and subjective satisfaction are paramount due to use is often discretionary and competition fierce Infrequent use of some applications means interfaces must be intuitive and easy to use online help is important Choosing functionality is difficult because the population has a wide range of both novice and expert users Competition cause the need for low cost New games and gaming devices! 1 -24

Usability motivations (continued) � Guitar Hero, a highly successful music playing game in which users learn to play popular songs and earn points for how well they keep up � The Guitar Hero web site shows potential users how to use the provided special small guitar and also hosts a community for discussions and runs contests 1 -25

Usability motivations (continued) � Exploratory, creative, and cooperative systems � Web browsing, search engines, artist toolkits, architectural design, software development, music composition, and scientific modeling systems � Collaborative work � Benchmarks are hard to describe for exploratory tasks and device users � With these applications, the computer should be transparent so that the user can be absorbed in their task domain 1 -26

Usability motivations (continued) � Sketchbook. TM design tool for digital artists from Autodesk. TM � A large number of tools and options are available through a rich set of menus and tool palettes (http: //www. sketchbook. com) 1 -27

Usability motivations (concluded) � Social technical systems � Complex systems that involve many people over long � � � time periods Voting, health support, identity verification, crime reporting Trust, privacy, responsibility, and security are issues Verifiable sources and status feedback are important Ease of learning for novices and feedback to build trust Administrators need tools to detect unusual patterns of usage 1 -28

Goals for our profession �Potential research topics �Reducing anxiety and fear of computer usage �Graceful evolution �Social media participation �Input devices �Information exploration 1 -29

Goals for our profession (concluded) �Providing tools, techniques, and knowledge for system implementers � Rapid prototyping is easy when using contemporary tools � Use general or self determined guideline documents written for specific audiences � To refine systems, use feedback from individual or groups of users �Raising the computer consciousness of the general public � Some novice users are fearful due to experience with poor product design � Good designs help novices through these fears by being clear, competent, and non threatening 1 -30

Managing Design Processes • Organizational Design to Support Usability • Four Pillars of Design • Development Methodology • Ethnographic Observation • Participatory Design Scenario Development • Social Impact Statements Legal Issues • Usability Testing and Laboratories 31

Organizational Design to Support Usability Competitive products with similar functionality? ● ● ● Usability engineering is critical Result: usability labs – Expert reviews Usability – tests ● User-interface architects, usability engineering managers (but typically no CUOs yet) ● Evidence, data may be required to show the business case for usability to managers ● Studies show usability testing can pay dividends 32

Organizational Design to Support Usability ● ● General usability labs, but per project userinterface architects ● Centralized expertise, decentralized application ● Different application domains. . . User-interface-building tool choice is vital to success 33

Organizational Design to Support Usability Characterization of design (Rosson and Carroll, ● 2002): Design is a process Not a state, or static ● ● ● – Design process is non-hierarchical Not strictly bottom-up or top– down Design is radically transformational – ● ● Some temporary solutions may have no role in finale design Design involves discovery of new goals Bottom-line: design is dynamic 34

Four Pillars of Design ● Successful user interface design process involves: ● User-interface requirements ● Guidelines documents & process ● User-interface software tools ● Expert reviews & usability testing 35

Four Pillars of Design ● User interface requirements ● Soliciting, clearly specifying user requirements always important development! ● Methods to solicit, specify different across organizations Common goals however, such as clearly specified: ● user community – tasks that users perform – ● Without properly defined requirements, we might be solving the wrong problem! 36

Four Pillars of Design 37

● Four Pillars of Design User interface requirements ● Don't make human operator actions into user interface requirements e. g. User must purchase a ticket within 1 minute (incorrect) – e. g. System will go to standby mode if ticket not purchased within 1 minute (correct) – ● Consider ethnographic observations to determine user-interface requirements 38

● Four Pillars of Design Guidelines documents and processes ● ● User-interface architecture should create set of working guidelines Guidelines can be created for: – – – ● Words, icons, graphics Screenlayout issues Input and out devices Action sequences Training Guideline creation == group work, involve everyone -> gains visibility, builds support! 39

● Four Pillars of Design Guidelines documents and processes ● Controversial guidelines? – ● Expert review, review by co– workers Test them empirically in the lab ● Concerns: enforcement, exemptions and enhancements ● Flexibility from “rigid practice” to “subject to change”? Multiple levels of guidelines for organization-wide standards, application-specific standards? 40

● Four Pillars of Design Guidelines documents and processes ● “Four Es” – Education ● – Enforcement ● – What process to verify interface adheres to guidelines? Exemption ● – How to train users of guidelines? How to exempt newcreative ideas quickly? Enhancement ● What process to review, update guidelines? 41

● Four Pillars of Design User-interface software tools ● ● Problem: development expensive, going back on design decisions is too Give customers early stage feedback – Printed versions. . . On-screen – displays. . . – Prototype menu, form-fill systems. . . – Power. Point slides, Flash, Ajax. . ● How will software development tools support UI aspect of project? 42

● Four Pillars of Design Expert reviews and usability testing ● Not that different an idea from other things really! – You rehearse a play before opening night. . . – You practice before the big game. . . ● Carry out small and large pilot tests of the UI ● Have the UI reviewed by UI, domain experts ● ● Experiments, tests with expected users, record results meticulously Surveys, interviews, automated analysis tools 43

● Development Methodologies Estimated 50% of software projects fail to reach goals (Jones, 2005) ● ● Software-engineering methodologies are effective in facilitating software dev. process ● ● Bad communication often to blame. . . But have they been as effective at understanding users, creating usable interfaces? Agile development responsive to userinterface development, usability needs 44

● Development Methodologies Different development methodologies might include. . . ● Approaches to specify detailed deliverables ● Incorporate cost/benefit, ROI analysis Management ● strategies ● ● UI design only one part. . . may have to co-exist with software-engineering methodologies Many, many methods exist, are advocated for different reasons 45

● Development Methodologies Rapid contextual design method (Kaufmann, 2005): ● Contextual inquiry – Planprepareconduct field interviews, review business practices Interpretation sessions and work modelling ● Group meetings, discussions, draw conclusions Model consolidation and affinity diagram building – ● – Take resulting conclusions to larger target population, gain more insight, consolidate models, create work patterns 46

● Development Methodologies Rapid contextual design method (Kaufmann, 2005) con't: ● Persona development – Develop fictitious characters to represent different users, bring their needs to focus Visioning ● – Use media to revive and walkthrough all the data from perspective of personas Storyboarding ● – Initial user-interface concepts, business rules, automation assumptions 47

● Development Methodologies Rapid contextual design method (Kaufmann, 2005) con't: ● User environment design Single, coherent representation built from storyboards Interviews and evaluations with paper prototypes, – ● mock-ups 48

● Ethnographic Observation Ethnography: ● Qualitative method to listen, observe the knowledge, workings and system of meanings of a group ● Traditional ethnographers emerse themselves in a culture for weeks or months ● UI designers do for days or hours ● To obtain relevant data ● Focus is to change, improve UI 49

● ● Ethnographic Observation Challenges to ethnographic observation ● Misinterpretation of observations ● Disrupt normal practices ● Overlooking important information Steps: preparation, field study, analysis, reporting ● Require situational interpretation ● Learning the technical, non-technical codes ● Data collection: qualitative and quantitative 50

● Ethnographic Observation Benefits of ethnographic observation: ● ● � Increased trust credibility � Designers learn complexities of target environment � Designer-user working relationships develop Users may become active participants in design 51

● Participatory Design Participatory design ● Positives ● ● “Direct involvement of people in the collaborative design of the things and technologies they use” ● Brings accurate info into the process. . . ● But the “investment” in the implementation seems to most influenceincrease user acceptance Negatives ● Costly, lengthened implementation period ● Bruised egos over rejected designers ● Incompetent users may influence design 52

● Participatory Design How to select users? Carefully. . . ● Competitive process – Emphasizes seriousness ● ● Repeated meetings Clear guidance on roles, influence 53

● Scenario Development Distribution of task frequencies and sequences is helpful knowledge ● ● Task frequency ● Table with user communities, tasks ● Each box contains relative frequency of tasks per user Task sequence ● ● Flowchart Transition diagram Thickness of line can indicate frequency ● 54

● ● Scenario Development Day-in-the-life scenarios Write scenarios down, act them out ● Particularly important for co-operative interfaces (e. g. Control room) ● Common or rare situations can be represented ● Novice and expert users Personas can be used ● ● Example scenario: Microsoft – Health Future Vision ● Seamless integration of I/O into environment, etc. 55

Social Impact Statement for Early Design Review Social impact statement ● ● ● Statement of anticipated impacts on users ● Risk minimizing if circulated among stakeholders Concerns like. . . ● Privacy invasion ● Restriction of information ● Poor security 56

Social Impact Statement for Early Design Review Potential outline (Schneiderman & Rose, 1996): ● ● Describe new system, benefits – ● Identify stakeholders, goals Address concerns, potential barriers Security, privacy Potential layoffs, job changes? – Individual rights vs societal good – – ● Outline development process – Estimated – schedule – Migration? 57

Social Impact Statement for Early Design Review Concerns: ● ● Evaluation by who? Review panel, managers, designers, end users, anyone affected – E. G. regulatory agencies Opportunities to propose – Public meetings? alternatives? – ● Enforcement how? – ● Review panel typically enforces Effort, cost, time in-line with project? 58

● Legal Issues Privacy concerns ● ● ● � Medical, legal, financial � Protect from unapproved access, illegal tampering, inadvertent loss � Laws can be complicated, hard to understand Safety, reliability ● Life-or-death decisions ● Lawsuits possible Copyright protection, patent protection ● Can users take info, images, music? 59

● Legal Issues Freedom of expression ● Can users say whatever they want? Can ● users access whatever they want? ● ● Who is responsible for libel, defamation of character, etc? Accessibility ● For disabled users 60

Usability Testing and Laboratories 61

Usability Testing and Laboratories (cont. ) • 1980 s: emergence of usability testing and laboratories • Result: – Sped up many projects – Produced dramatic cost savings – Increased industry jobs • A typical modest usability lab: – One 10’ x 10’ room for the participants to do their work – Another 10’ x 10’ room for the testers and observers – Separated by a half-silvered mirror © 2010 Pearson Addison-Wesley. All rights reserved. 4 -62

Usability Testing and Laboratories (cont. ) • Participants should be chosen to represent the intended user communities, with attention to – background in computing – experience with the task (domain) – motivation – education • Participation should always be voluntary • Informed consent should be obtained 63

Usability Testing and Laboratories (cont. ) • Videotaping participants performing tasks – Often valuable for later review • Use caution in order to not interfere with participants • Invite users to use think aloud protocol as they are performing the tasks © 2010 Pearson Addison-Wesley. All rights reserved. 4 -9 64

Usability Testing and Laboratories (cont. ) • Many variant forms of usability testing tried: – Paper mockups – Discount usability testing – Competitive usability testing – Universal usability testing – Field test and portable labs – Remote usability testing – Can-you-break-this tests 65

Usability Testing and Laboratories (cont. ) In this eye-tracking setup, the participant wears a helmet that monitors and records where on the screen the participant is looking 66

Usability Testing and Laboratories (cont. ) More portable eye-tracking devices 67