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Chapter 7 PowerPoint Presentation

Chapter 7

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Chapter 7

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  1. User Interface, Input, and OutputDesign Chapter 7

  2. Introduction • User interface, input, and output design continues the systems design phase of the SDLC • User interface design includes user interaction with the computer, as well as input and output issues

  3. User Interface Design • After the logical model is constructed, systems analysts turn their attention to the physical design • A key design element is the user interface (UI) • Consists of all the hardware, software, screens, menus, functions, and features that affect two-way communications between the user and the computer

  4. User Interface Design • Human-Computer Interaction • Human-computer interaction (HCI) describes the relationship between computers and people who use them to perform business-related tasks • IBM uses its Almaden computer science research site to focus on users and how they experience technology

  5. User Interface Design • Human-Computer Interaction • IBM traces the history and evolution of the human-computer interface — beginning with users typing complex commands in green text on a black screen, through the introduction of the graphical user interface (GUI) • Dr. Clare-Marie Karat states that “in this new computer age, the customer is not only right, the customer has rights”

  6. User Interface Design • Basic Principles of User-Centered Design • Understand the underlying business functions • Maximize graphical effectiveness • Profile the system’s users • Think like a user • Use prototyping • Usability metrics

  7. User Interface Design • Basic Principles of User-Centered Design • Design a comprehensive(完整的) interface • Continue the feedback process • Document the interface design

  8. User Interface Design • Guidelines for User Interface Design • Follow eight basic guidelines • Focus on basic objectives • Build an interface that is easy to learn and use • Provide features that promote efficiency • Make it easy for users to obtain help or correct errors • Minimize input data problems

  9. User Interface Design • Guidelines for User Interface Design • Follow eight basic guidelines • Provide feedback to users • Create an attractive layout and design • Use familiar terms and images • Good user interface design is based on a combination of ergonomics(人體工學), aesthetics(美學), and interface technology

  10. User Interface Design • User Interface Controls (Examples: p. 316) • Menu bar • Toolbar • Command button • Dialog box • Text box • Toggle button

  11. User Interface Design • User Interface Controls • List box – scroll bar • Drop-down list box • Option button, or radio button • Check box • Calendar control • Switchboard

  12. User Interface Design • User Interface Controls

  13. Input Design • Input technology has changed dramatically in recent years • The quality of the output is only as good as the quality of the input • Garbage in, garbage out (GIGO) • Data capture: users an automated or manually operated device to identify source data and convert it into computer readable form. Ex. Bar code reader • Data entry: the process of manually entering data into IS.

  14. Input Design • Input and Data Entry Methods • Batch input • Batch • Online input • Online data entry • Source data automation • Magnetic data strips or swipe scanners • POS, ATMs

  15. Input Design • Input and Data Entry Methods • Tradeoffs • Unless source data automation is used, manual data entry is slower and more expensive than batch input because it is performed at the time the transaction occurs and often done when computer demand is at its highest • The decision to use batch or online input depends on business requirements

  16. Input Design • Input Volume • Guidelines will help reduce input volume • Input necessary data only • Do not input data that the user can retrieve from system files or calculate from other data • Do not input constant data • Use codes

  17. Input Design • Designing Data Entry Screens • Most effective method of online data entry is form filling • Guidelines to help design data entry screens • Restrict user access to screen locations where data is entered • Provide a descriptive caption for every field, and show the user where to enter the data and the required or maximum field size

  18. Input Design • Designing Data Entry Screens • Guidelines to help design data entry screens • Display a sample format if a user must enter values in a field in a specific format • Require an ending keystroke for every field • Do not require users to type leading zeroes for numeric fields (i.e. 045) • Do not require users to type trailing zeroes for numbers that include decimals (i.e. 98.00)

  19. Input Design • Designing Data Entry Screens • Guidelines to help design data entry screens • Display default values so operators can press the ENTER key to accept the suggested value • Use a default value when a field value will be constant for successive records or throughout the data entry session (ex. Same date) • Display a list of acceptable values for fields, and provide meaningful error messages

  20. Input Design • Designing Data Entry Screens • Guidelines to help design data entry screens • Provide a way to leave the data entry screen at any time without entering the current record (see Fig. 7-24, 7-23, of p. 322) • Provide users with an opportunity to confirm the accuracy of input data before entering it (ex.add this record? (Y/N)) • Provide a means for users to move among fields on the form

  21. Input Design • Designing Data Entry Screens • Guidelines to help design data entry screens • Design the screen form layout to match the layout of the source document • Allow users to add, change, delete, and view records • Provide a method to allow users to search for specific information

  22. Input Design • Input Errors • Reducing the number of input errors improves data quality • A data validation check improves input quality by testing the data and rejecting any entry that fails to meet specified conditions

  23. Input Design • Input Errors • At least eight types of data validation checks • Sequence check • Existence check • Data type check • Range check – limit check • Reasonableness check

  24. Input Design • Input Errors • At least eight types of data validation checks • Validity check – referential integrity • Combination check • Batch controls

  25. Input Design • Source Documents • Source document • Form layout • Heading zone • Control zone • Instruction zone • Body zone • Totals zone • Authorization zone

  26. Input Design • Source Documents • Information should flow on a form from left to right and top to bottom to match the way users read documents naturally • A major challenge of Web-based form design is that most people read and interact differently with on-screen information compared to paper forms

  27. Input Design • Source Documents • Dr. Jakob Nielson believes that users scan a page, picking out individual words and sentences • As a result, Web designers must use scannable text to capture and hold a user’s attention (Example: p. 327, Fig. 7-29) • Layout and design also is important on Web-based forms

  28. Input Design • Input Control • Every piece of information should be traceable back to the input data • Audit trail • Data security • Records retention policy • Encrypted – encryption

  29. Output Design Issues • Before designing output, ask yourself several questions: • What is the purpose of the output? • Who wants the information, why it is it needed, and how will it be used? • What specific information will be included? • Will the output be printed, viewed on-screen, or both?

  30. Output Design Issues • Before designing output, ask yourself several questions: • When will the information be provided, and how often must it be updated? • Do security or confidentiality issues exist? • Your answers will affect your output design strategies

  31. Output Design Issues • Types of Output • In the systems design phase, you must design the actual reports, screen forms, and other output delivery methods • Internet-based information delivery • E-mail • Audio

  32. Output Design Issues

  33. Output Design Issues • Types of Output • Automated facsimile systems • Faxback systems • Computer output microfilm (COM) • Microfilm • Computer output to laser disk (COLD)

  34. Output Design Issues • Specialized Forms of Output • An incredibly diverse marketplace requires a variety of specialized output • Output from one system often becomes input into another system • Although digital technology has opened new horizons in business communications printed output still is the most common type of output

  35. Printed Output • Although many organizations strive to reduce the flow of paper and printed reports, few firms have been able to eliminate printed output totally • Because they are portable, printed reports are convenient, and even necessary in some situations • Turnaround documents: become another input source data for other IS

  36. Printed Output • Types of Reports • Detail reports (Example: Fig 7-32, p. 332) • Detail line • Control field • Control break • Control break report • Can be quite lengthy • Better alternative is to produce an exception report

  37. Printed Output • Types of Reports • Exception reports • Are useful when the user wants information only on records that might require action • Ex. Fig. 7-34, p. 334 • Summary reports • Reports used by individuals at higher levels in the organization include less detail than reports used by lower-level employees • Ex. Fig. 7-35, p. 334

  38. Printed Output • User Involvement in Report Design • Printed reports are an important way of delivering information to users, so recipients should approve all report designs in advance • To avoid problems submit each design for approval as it is completed, rather than waiting to finish all report designs • Mock-up: a sample report in design stage to show it to the users.

  39. Printed Output • Report Design Example • Revisit the Employee Hours report shown in Figure 7-36. Although the report follows many of the design guidelines discussed, you still could improve it • Too much detail is on the page, forcing users to search for the information they need

  40. Printed Output • Designing Character-Based Reports, the traditional way to design the report (see p. 340) • Many systems still produce one or more character-based reports • When report designers create or modify a character-based report, they use a traditional tool that still works well, called a printer spacing chart

  41. Printed Output • Printing Volume and Time Requirements • High printing volume of reports can significantly increase a system’s TCO • Length calculations • Time calculations • Ppm (pages per minute) • Line printers

  42. Printed Output • Output Control and Security • Output must be accurate, complete, current, and secure • Output security • The IT department is responsible for output control and security measures • Many companies have installed diskless workstations