INFO 355Week #71 Systems Analysis II User and system interface design INFO 355 Glenn Booker

User and System Interfaces  User interfaces involve a human Internal or external Ease of use, efficiency, device-specific  System interfaces are largely automated Little or no human intervention Direct communication with other systems, or automated communication with users INFO 355Week #72

User-centered design  Focus early on the users and their work  Evaluate designs to ensure usability  Use iterative development  What do users know? How do they learn? How do they work? What motivates them? INFO 355Week #73

User-centered design  Usability is the degree to which a system is easy to learn and use May vary for different types of users Learning very different from using  Consider novice versus experienced user needs INFO 355Week #74

HCI Metaphors  Metaphors are analogies between UI and physical objects Windows uses desktop, direct manipulation, and document metaphors  Dialog metaphor is a conversation between user and computer INFO 355Week #75

UI Design Concepts  Affordance means appearance of a feature implies its function  Visibility means control is visible so user knows it’s available and/or responding  Use consistency in function and appearance of the UI INFO 355Week #76

UI Design Concepts  Use shortcuts for advanced users  Provide audible and/or visual feedback  End dialogs with clear closure  Anticipate common errors and help user avoid them Give clear error messages and how to fix them INFO 355Week #77

UI Design Concepts  Make it easy to reverse actions  Reduce short term memory needs of users  Group use cases to produce logical menu hierarchies 5-10 items per menu Group by subsystem and/or actor  Might write out dialogs or sketch storyboards INFO 355Week #78

UI Design  Constructing the UI depends on the tools available  Use consistent layout and formatting (same look and feel, use of color, function keys, etc.) Use clear labels and headings Distribute and order UI contents Use font and colors methodically INFO 355Week #79

UI Design  Data entry should use common controls to reduce errors and speed input Text box, list box, combo box, radio buttons, check boxes  Consider standard controls for navigation and window manipulation INFO 355Week #710

Web interfaces  Use appropriate technologies to implement web browser interfaces (CSS)  Consider performance needs Are you using client-side or server-side technologies? How much data is being sent? How fast can you expect their Internet or network connection to be? INFO 355Week #711

Web interfaces  What network capacity is available for multimedia data?  Do some users have special needs (screen readers, voice recognition, etc.)? INFO 355Week #712

Handheld devices  Consider the limits on handheld devices Small screen (4”, 480x320 px) Small keyboard or touch screen Limited network speed App design guidelines and toolkits INFO 355Week #713

System Interfaces  Consider possible types of interfaces to other systems I/O from and to other systems Automated I/O I/O to external databases  Electronic data interchange (EDI) has been around decades, now often going to XML INFO 355Week #714

Designing System Inputs  Need to identify devices used Magnetic strip, barcode, RFID, etc.  Identify all input data for each device  Define controls for each input  Reduce errors by avoiding human interference, and validate data when entered INFO 355Week #715

Designing System Inputs & Outputs  Only enter unique information  Define details of each data field or group entered  Design outputs to get the right information, right place, right time, to the right people  Define type of each output, specify controls needed, and prototype each INFO 355Week #716

Design Reports  Reports, statements, and turnaround documents fall into four types Detailed reports Summary reports Exception reports Executive reports  Have internal vs. external reports, and electronic vs. printed reports INFO 355Week #717

Design Reports  Often want to “drill down” in reports to get more details  Consider graphic outputs and/or audio outputs Bar or column charts, pie charts, scatter plots, line or run charts, etc. INFO 355Week #718