Design Discovery 1 Interface Hall of Shame or

Design Discovery 1

Interface Hall of Shame or Fame? 2

Interface Hall of Shame l ? 3

Interface Hall of Shame l l ? Requires recall over recognition l want recognition over recall 4

Outline l l l Usability Customer-centered design Design process Involving the customer Administrivia Task Analysis 5

Usability Metrics l Ease of learning l l perform tasks quickly and efficiently Minimal error rates l l remember how from one session to the next Productivity l l faster the second time and so on. . . Recall l l ? if they occur, good feedback so user can recover High user satisfaction l confident of success 6

Customer-centered Iterative Design l l l Developers working with target customers Think of the world in customers terms Understanding work process Not technology-centered/feature driven Iterate at every stage Design Prototype Evaluate 7

Waterfall Model (Soft. Eng. ) Initiation Application Description Analysis Requirements Specification System Design Implementation Product 8 ?

Waterfall vs. Iterative Customer-Centered Design l Focus differs l l WF lacks customer’s perspective l customer is the “client” WF has no feedback l Initiation Application Description Prototype Design high cost of fixing errors l increases by factor of 10 at each stage l iterative design finds these earlier Analysis Requirements Specification System Design Evaluate Design Implement Product 9

Why Do It? l Nearly 25% of all applications projects fail. Why? l l l overrun budgets & management pulls the plug others complete, but are too hard to learn/use Solution is customer-centered design. Why? l l l easier to learn & use products sell better can help keep a product on/ahead of schedule training costs reduced 10

Design l Design is driven by requirements l l l what the artifact is for not how it is to be implemented A design represents the artifact l for UIs these include (? ) l l screen sketches or storyboards flow diagrams/outline showing task structure executable prototypes representations simplify Write essay start word processor write outline fill outline Start word processor find word processor icon double click on icon Write outline write down high-level ideas . . . 11

Web Design Representations l l Designers create representations of sites at multiple levels of detail Web sites are iteratively refined at all levels of detail Site Maps Storyboards Schematics Mock-ups 12

Design Process Discovery Design Exploration Design Refinement Production 13

Design Process: Discovery Assess needs l Design Exploration l Design Refinement l Production l understand client’s expectations determine scope of project characteristics of customers evaluate existing interface and/or competition 14

Understanding the Customer l How do your customers work? l l How do your customers think? l l l task analysis, interviews, & observation understand human cognition observe users performing tasks How do your customers interact with UIs? l observe! 15

Example of Design Failure l BART “Charge-a-Ticket” Machines l l allow riders to buy BART tickets or add fare takes ATM cards, credit cards, & cash 16

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Example of Design Failure l BART “Charge-a-Ticket” Machines l l l allow riders to buy BART tickets or add fare takes ATM cards, credit cards, & cash Problems (? ) l one “path” of operation l l ticket type -> payment -> ticket BART Plus has minimum of $28, no indication of this until after inserting >= $1 l can’t switch to regular BART ticket order of payment / card insertion non-standard large dismiss transaction button does nothing 19

Lessons from the BART machine l l Failure to create convenient machine Did the designers understand/care l l range of customers using the machine what tasks they would want to carry out some would find the behavior of the machine disconcerting How can we avoid similar results? l “What is required to perform the customer’s task? ” 20

Task Analysis l Find out l l l who the intended customers are what tasks they need to perform Observe existing work practices Create scenarios of actual use Try-out new ideas before building software 21

Why Task Analysis? l System will fail if it l l does not do what the customer needs is inappropriate to the customer l l “the system must match the customers’ tasks” Why not define “good” interfaces? l l infinite variety of tasks & customers guidelines are usually too vague l e. g. , “give adequate feedback” 22

Questions l l l Task Analysis Who is going to use system? What tasks do they now perform? What tasks are desired? How are the tasks learned? Where are the tasks performed? What’s the relationship between user & data? 23

Questions (cont. ) l l l What other tools does the customer have? How do customers communicate with each other? How often are the tasks performed? What are the time constraints on the tasks? What happens when things go wrong? 24

Who? l Identity? l l l in-house or specific customer is easy need several typical customers for broad product Background Skills Work habits and preferences Physical characteristics l height? 25

Who (BART)? l Identity? l people who ride BART l l Background l l l business people, students, disabled, elderly, etc. have an ATM or credit card use BART fare machines Skills l l know how to put cards into ATM know how to buy BART tickets 26

Who (BART cont. )? l Work habits and preferences l l not applicable Physical characteristics l varying heights -> don’t make it too high or too low! 27

Talk to Them l l Find some real customers Talk to them l l l find out what they do how would your system fit in Are they too busy? l buy their time l t-shirts, coffee mugs, etc. 28

What Tasks? l l l Important for both automation & new functionality Relative importance of tasks? Observe customers l on-line billing example l small dentists office had billing automated l assistants were unhappy with new system l old forms contained hand-written margin notes § e. g. , patient A’s insurance takes longer than most, etc. 29

What Tasks (BART)? l Old tasks? l l cash to buy new ticket cash to add fare to existing ticket cash or credit to buy a BART Plus at window New tasks? l cash, credit, or ATM card to l l buy new ticket add fare to existing ticket buy a BART Plus ticket Level of detail can vary 30

How are Tasks Learned? l l What does the customer need to know? Do they need training? l l l academic general knowledge / skills special instruction / training 31

How are Tasks Learned (BART)? l Walk up & use system (? ) l l Training? l l can’t assume much background/training too time consuming Must be simple & similar to existing systems l l BART machines ATM machines 32

Where is the Task Performed? l l Office, laboratory, point of sale? Effects of environment on customers? Customers under stress? Confidentiality required? l l Do they have wet, dirty, or slippery hands? Soft drinks? Lighting? Noise? 33

Where (BART)? Train Station l Loud l l dependence on voice I/O not a good idea Others looking over your shoulder l l not private PIN input must be confidential l l don’t confirm with sound Lighting is dim l make sure messages are readable 34

What is the Relationship Between Customers & Data? l Personal data l l l Common data l l always accessed at same machine? do customers move between machines? used concurrently? passed sequentially between customers? Remote access required? Access to data restricted? 35

Data Relationships (BART) l Personal data l l l Common data (? ) l l l fare rules (e. g. , how much for BART Plus) used concurrently Access to data restricted? l l customers may use any machine store info on BART card only you can use your ATM or credit card No need for remote access 36

What Other Tools Does the Customer Have? l l More than just compatibility How customer works with collection of tools l example: automating lab data collection l how is data collected now? l by what instruments and manual procedures? l how is the information analyzed? l are the results transcribed for records or publication? l what media/forms are used and how are they handled? 37

How do Customers Communicate With Each Other? l l Who communicates with whom? About what? Follow lines of the organization? Against it? Example: assistant to manager l l installation of computers changes communication between them people would rather change their computer usage than their relationship [Hersh 82] 38

A Better Subway Machine: Hong Kong 39

Summary l Customer-centered design is different than traditional methodologies l l leads to solving problems up front (cheaper) Know thy customer & involve them in design l answer questions before designing l who, what, where, when, how often? l relationship between customers & data? l what other tools do customers have? l what happens when things go wrong? 40