phase 3. design phase chapter 7 – user interface, input, and output design
TRANSCRIPT
Phase 3. Design Phase
Chapter 7 – User Interface, Input, and Output Design
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
User Interface 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
Figure 7-2
User Interface Design
• Evolution of the User Interface– As information management evolved from
centralized data processing to dynamic, enterprise-wide systems, the primary focus also shifted — from the IT department to the users themselves
– User-centered system– Requires an understanding of human-
computer interaction and user-centered design principles
Figure 7-3 Figure 7-4
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
Figure 7-5 Figure 7-6
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
• Storyboard• Usability metrics
User Interface Design
• Basic Principles of User-Centered Design– Design a comprehensive interface– Continue the feedback process– Document the interface design
Figure 7-8
User Interface Design
• 8 Guidelines for User Interface Design– Good user interface design is based on a
combination of ergonomics, aesthetics, and interface technology
1. Focus on basic objectives• Facilitate the system design objectives• Create a design that is easy to learn and
remember• Design the interface to improve user efficiency
and productivity• Write commands, actions, and system
responses that are consistent and predictable
User Interface Design
• Guidelines for User Interface Design2. Build an interface that is easy to learn and
use• Label clearly all controls, buttons, and icons• Select only those images that a user can
understand easily• Provide on-screen instructions that are logical,
concise, and clear• Show all commands in a list of menu items
Figure 7-10
Figure 7-11
User Interface Design
• Guidelines for User Interface Design3. Provide features that promote efficiency
• Organize tasks, commands, and functions in groups that resemble actual business operations
• Create alphabetical menu lists• Provide shortcuts so experienced users can
avoid multiple menu levels• Use default values if the majority of values in a
field are the same
Figure 7-12
Figure 7-13
Figure 7-14
User Interface Design
• Guidelines for User Interface Design4. Make it easy for users to obtain help or
correct errors• Ensure that Help is always available• Provide user-selected Help and context-sensitive
Help• Provide a direct route for users to return to the
point from where Help was requested• Include contact information
Figure 7-15
Figure 7-16
User Interface Design
• Guidelines for User Interface Design5. Minimize input data problems
• Provide data validation checks• Display event-driven messages and reminders• Establish a list of predefined values that users
can click to select• Build in rules that enforce data integrity• Use input masks
Figure 7-17
User Interface Design
• Guidelines for User Interface Design6. Provide feedback to users
• Display messages at a logical place on the screen
• Alert users to lengthy processing times or delays• Allow messages to remain on the screen long
enough for users to read them• Let the user know whether the task or operation
was successful or not
User Interface Design
• Guidelines for User Interface Design7. Create an attractive layout and design
• Use appropriate colors to highlight different areas of the screen
• Use special effects sparingly• Use hyperlinks that allow users to jump to related
topics• Group related objects and information
User Interface Design
• Guidelines for User Interface Design8. Use familiar terms and images
• Remember that users are accustomed to a pattern of red=stop, yellow=caution, and green=go
• Provide a keystroke alternative for each menu command
• Use familiar commands• Provide a Windows look and feel in your
interface design if users are familiar with Windows-based applications
User Interface Design
• User Interface Controls– Menu bar– Toolbar– Command button– Dialog box– Text box– Toggle button
– List box – scroll bar– Drop-down list box– Option/radio button – Check box– Calendar control– Switchboard
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– Data entry
Figure 7-21
Figure 7-22
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
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
Input Design
• Input Volume– Guidelines will help reduce input volume
1. Input necessary data only
2. Do not input data that the user can retrieve from system files or calculate from other data
3. Do not input constant data
4. Use codes
Input Design
• Designing Data Entry Screens– Most effective method of online data entry
is form filling– Guidelines will help you design data entry
screens1. Restrict user access to screen locations where
data is entered
2. Provide a descriptive caption for ever field, and show the user where to enter the data and the required or maximum field size
Input Design
• Designing Data Entry Screens– Guidelines will help you design data entry
screens3. display a sample format if a user must enter
values in a field in a specific format
4. Require an ending keystroke for every field
5. Do not require users to type leading zeroes for numeric fields
6. Do not require users to type trailing zeroes for numbers that include decimals
Input Design
• Designing Data Entry Screens– Guidelines will help you design data
entry screens7. Display default values so operators can
press the ENTER key to accept the suggested value
8. Use a default value when a field value will be constant for successive records or throughout the data entry session
9. Display a list of acceptable values for fields, and provide meaningful error messages
Input Design
• Designing Data Entry Screens– Guidelines will help you design data entry
screens10.Provide a way to leave the data entry screen at
any time without entering the current record11.Provide users with an opportunity to confirm the
accuracy of input data before entering it12.Provide a means for users to move among
fields on the form
Figure 7-24
Input Design
• Designing Data Entry Screens– Guidelines will help you design data entry
screens13.Design the screen form layout to match the
layout of the source document
14.Allow users to add, change, delete, and view records
15.Provide a method to allow users to search for specific information
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
Input Design
• Input Errors– At least eight types of data validation
checks1. Sequence check
2. Existence check
3. Data type check
4. Range check – limit check
5. Reasonableness check
Input Design
• Input Errors– At least eight types of data validation
checks6. Validity check – referential integrity
7. Combination check
8. Batch controls
Figure 7-25
Input Design
• Source Documents– Source document – Form layout– Heading zone– Control zone– Instruction zone– Body zone– Totals zone– Authorization zone
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
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
– Layout and design also is important on Web-based forms
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
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?
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
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
Figure 7-30
Figure 7-31
Output Design Issues
• Types of Output– Automated facsimile systems
• Faxback systems
– Computer output microfilm (COM)• Microfilm
– Computer output to laser disk (COLD)
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
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
Printed Output
• Types of Reports– Detail reports
• Detail line• Control field• Control break• Control break report• Can be quite lengthy• Better alternative is to produce an exception
report
Figure 7-32
Figure 7-33
Printed Output
• Types of Reports– Exception reports
• Are useful when the user wants information only on records that might require action
– Summary reports• Reports used by individuals at higher levels in the
organization include less detail than reports used by lower-level employees
Figure 7-34
Figure 7-35
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
Printed Output
• Report Design Principles– Printed reports must be attractive,
professional, and easy to read– Report headers and footers– Page headers and footers– Column heading alignment
• Space columns of information carefully
Figure 7-36
Figure 7-37
Printed Output
• Report Design Principles– Field order
• Fields should be displayed and grouped in a logical order
– Grouping detail lines• It is meaningful to arrange detail lines in groups• Group header• Group footer
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
Figure 7-38
Figure 7-39
Printed Output
• Other Design Issues– Good design standards produce reports that
are uniform and consistent– When a system produces multiple reports,
each report should share common design elements
– After a report design is approved, you should document the design in a report analysis form
Printed Output
• Designing Character-Based Reports– 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
Figure 7-40
Printed Output
• Printing Volume and Time Requirements– High volume of reports can significantly
increase a system’s TCO– Length calculation– Time calculations
• Ppm (pages per minute)• Line printers
Figure 7-41
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