Information Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 1XXIV. User Interface DesignXXIV. User Interface DesignWhat is Human-Computer Interaction?Affordances, Mappings, Mental Models,Feedback, Forcing Functions, LearningHow to Design InterfacesUser Dialogue DesignInputs and OutputsInformation Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 2HCI = Human-Computer InteractionHCI = Human-Computer InteractionWhy should a Systems Analyst Know HCI?Why should a Systems Analyst Know HCI?n 40-60% of today’s software does user interface management -high interactivity with the user, much end-user programmingn User interactivity is only going to get more complexü 3D graphics and Virtual Realityü More augmented reality activitiesn Many of the problems with introducing and maintaining asystem can be traced back to a bad interface designü Users sabotage systems they don’t understandü Users make more errors when dealing with systems thatare difficult to usen A good user interface can reduce coding costs, reduce highcosts of interface problems, reduce serious life-threateningerrors, sell more products, lead to increased use of computersInformation Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 3Increased ProductivityIncreased Productivity20 usersX 230 daysX 100 screens per dayX 10 sec per screen (savings)= 1278 hours or 32 weeksInformation Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 4Reduced Training CostsReduced Training Costs20 employeesX 2 systems/applications per yearX 2 1/2 days per application (saved)= 100 days or 20 weeks of savings Training and support often more costlyTraining and support often more costly than hardware and softwarethan hardware and softwareInformation Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 5Preventable User ErrorsPreventable User Errors500 usersX 20 errors per yearX 15 minutes per error= 2500 hours lost or 63 weeksInformation Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 6Increased ProductivityIncreased Productivity500 menu selections per dayX 2 sec per selection (saved)X 230 days per year= 320 hours or 8 weeksFor a $100K person-year cost, saved timeFor a $100K person-year cost, saved timetranslates to $15,000translates to $15,000Information Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 7Serious Life-Threatening ErrorsSerious Life-Threatening Errorsn Analysis of transcript of 911 call announcing bomb inCentennial Park at the Atlanta Olympics indicated that 20minutes were needed to call dispatchersDispatch system required an address for Centennial ParkDispatch operators could not find anyone who knew addressBomb was set to go off 30 minutes after calln Airline crashed into a mountainside in Colombia in 1996,killing all aboard (including a well-known computer scientistand his whole family!)Pilot typed in “R” rather than full name of airportGuidance system took first airport in the list beginning with“R” which was the wrong airportPlane ran into mountain...Information Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 8User Interface EconomicsUser Interface Economicsn Good user interfaces sell systems!ü Windows is a copy of the Macintosh interfaceü The Mac interface is a copy of Bravo - developed by userinterface researchers at Xerox PARCn User interface capabilities and awareness help get contractsn Poor user interfaces can cripple a system that is outstanding inall other respectsn Computer-driven interfaces placed in most mechanicalproducts we knowü Classic problem of users not being able to set the clock ontheir VCRü Users often can’t use a photocopy machine, a fax machine,a cash register, a candy machine, a bank machine or evena telephoneü Cars will eventually be completely computer driven...Information Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 9Why Are User Interfaces Poor?Why Are User Interfaces Poor?n Inadequate training of people developing interfacesn Diversity of knowledge required to design good interfacesn Rapid technological advancesn Reluctance of companies to commit resourcesn Poor management - programmers do not talk to user designteams and vice versan User Interface specialists rarely involvedn The "bricklayers" (programmers) are left to design the userinterface, by default“Ignorance by software engineers of usability“Ignorance by software engineers of usabilityand how to measure it is roughly equivalent toand how to measure it is roughly equivalent toan electronics engineer not knowingan electronics engineer not knowingwhat volts and watts are and how to measure them."what volts and watts are and how to measure them."Information Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 10What’s Wrong with this Interface Design?What’s Wrong with this Interface Design?Design of User Interface for CAVECAT Media SpaceDesign of User Interface for CAVECAT Media SpaceInformation Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 11Why is thisWhy is thisDesignDesignBetter?Better?Design of UserDesign of UserInterface forInterface forTelepresenceTelepresenceMedia SpaceMedia SpaceInformation Systems Analysis and Design csc3402001 Marilyn Mantei and John MylopoulosInterface Design -- 12Some Basic Human CharacteristicsSome Basic Human Characteristicsn Humans like to problem solve, but don’t like unsolvable problems!n Humans are always learning, but learning is hard!n Humans use prior learning to support new learning.n Users don’t
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