Source Interface Hall of Shame Fall 2004 6 831 UI Design and Implementation 1 Fall 2004 6 831 UI Design and Implementation Iterative Design 2 Requirements Design Design Evaluate Implement Code Integration Task Analysis Acceptance Release Fall 2004 6 831 UI Design and Implementation 3 Fall 2004 6 831 UI Design and Implementation 4 1 User interface design is risky Requirements So we re likely to get it wrong Design Users are not involved in validation until acceptance testing Code So we won t find out until the end Integration UI flaws often cause changes in requirements and design Acceptance So we have to throw away carefully written and tested code Release Fall 2004 6 831 UI Design and Implementation 5 Fall 2004 6 831 UI Design and Implementation Evaluate 6 Every iteration corresponds to a release Design Fall 2004 Evaluation complaints feeds back into next version s design Using your paying customers to evaluate your usability Implement 6 831 UI Design and Implementation They won t like it They won t buy version 2 7 Fall 2004 6 831 UI Design and Implementation 8 2 Design Implement Evaluate Fall 2004 6 831 UI Design and Implementation 9 Fall 2004 6 831 UI Design and Implementation 0 Early iterations use cheap prototypes Parallel design is feasible build test multiple prototypes to explore design alternatives Design Later iterations use richer implementations after UI risk has been mitigated Every prototype is evaluated Users involved in all iterations 8 More iterations generally means better UI Only mature iterations are seen by the world Fall 2004 6 831 UI Design and Implementation Evaluate 11 Fall 2004 12 4 35 6 7 1 2 3 4 5 6 7 8 10 1 Task analysis Design sketches Paper prototype In class user testing Computer prototype Heuristic evaluation Implementation User testing Implement 6 831 UI Design and Implementation 12 3 2 3 Cheap prototypes 4 First step of user centered design User analysis who is the user Task analysis what does the user need to do Scenarios User guides Simulation Wizard of Oz Prototyping tools IBM Voice Toolkit Iterative design 200 iterations for user guide Evaluation at every step You are not the user Non English speakers had trouble with alphabetic entry on telephone keypad Fall 2004 5 6 831 UI Design and Implementation 13 Identify characteristics of target user population 6 831 UI Design and Implementation 6 831 UI Design and Implementation 14 Many applications have several kinds of users Example Olympic Message System Age gender ethnicity Education Physical abilities General computer experience Skills typing reading Domain experience Application experience Work environment and other social context Relationships and communication patterns Fall 2004 Fall 2004 Athletes Friends family Telephone operators Sysadmins 15 Fall 2004 6 831 UI Design and Implementation 16 4 4 6 Grocery shoppers Wide range of ages 10 80 and physical abilities height mobility strength No computer experience No training walk up and use Knowledge of food but not about supermarket inventory techniques Supermarket shoppers often ask each other for help finding things Questionnaires Interviews Observation Obstacles Developers and users may be systematically isolated from each other Tech support shields developers from users Marketing shields users from developers Major user classes Family shopping is often done by women often accompanied by small children Store clerks who need to help shoppers Some users are expensive to talk to Doctors executives union members 6 831 UI Design and Implementation 17 4 Fall 2004 6 831 UI Design and Implementation Identify the individual tasks the program might solve Each task is a goal what not how Often helps to start with overall goal of the system and then decompose it hierarchically into tasks 4 Goal What must be done first to make it possible Preconditions Tasks on which this task depends Information that must be known to the user What steps are involved in doing the task Subtasks Subtasks may be decomposed recursively Enter groceries into register Bag groceries Pay 6 831 UI Design and Implementation 18 What needs to be done Overall goal shoppers pay for their own groceries Tasks Fall 2004 7 Who are the users Techniques Fall 2004 19 Fall 2004 6 831 UI Design and Implementation 20 5 6 7 2 8 Front of supermarket standing up How often is the task performed Enter groceries into register At most a few times a week Preconditions What are its time or resource constraints A minute or two All the groceries you want are in your cart How is the task learned By trying it By watching others By being shown how by store personnel Subtasks Enter prepackaged item Enter loose produce 6 831 UI Design and Implementation What can go wrong Exceptions errors emergencies Barcode is missing or smudged Shopper wants to buy alcohol or cigarettes Who else is involved in the task 21 Fall 2004 4 6 831 UI Design and Implementation 6 831 UI Design and Implementation 22 4 Interviews with users Direct observation of users performing tasks Fall 2004 Where is the task performed Goal Fall 2004 4 4 Duplicating a bad existing procedure in software Failing to capture good aspects of existing procedure 23 Fall 2004 6 831 UI Design and Implementation 24 6 3 4 6 Observe users doing real work in the real work environment Be concrete Establish a master apprentice relationship Questions to ask Why do you do this goal How do you do it subtasks Look for weaknesses in current situation Goal failures wasted time user irritation User shows how and talks about it Interviewer watches and asks questions Contextual inquiry Participatory design Fall 2004 6 831 UI Design and Implementation Challenge assumptions and probe surprises 25 Fall 2004 6 Include representative users directly in the design team OMS design team included an Olympic athlete as a consultant Fall 2004 6 831 UI Design and Implementation 9 6 831 UI Design and Implementation 26 4 Model View Controller paper 27 Fall 2004 6 831 UI Design and Implementation 28 7
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