1. Chapter 12 Designing Interfaces and Dialogues
Modern Systems Analysis and Design Fourth Edition Jeffrey A. Hoffer Joey F. George Joseph S. Valacich
Chapter 12
Designing Interfaces and Dialogues

2. Learning Objectives
Explain the process of interface and dialogue design.
Contrast and apply methods for interacting with a system.
List and describe various input devices and factors affecting their usability.
Describe guidelines for designing interface layout, data entry field structure, feedback, and system help.
Design graphical user interfaces.

4. Interface/Dialogue Design
Layout (of text, and table data)
Structuring data entry
Controlling data input (validation and format controls)
Feedback (prompting, status, warning, and error messages)
Dialogue sequencing

5. Deliverables and Outcomes
A typical interface/dialogue design specification:
Similar to form design, but includes multiple forms and dialogue sequence specifications

6. Characteristics for Consideration
User: experience, skills, motivation, education, personality
Tasks: differ in amount of information that must be obtained or provided
Task demands: time pressure, cost of errors, work durations (fatigue)
System: the platform on which the system is constructed will influence interaction styles and devices.
Environment:
social issues: user’s role and status
physical issues: lighting, sound, task interruptions, temperature, humidity

7. Interface Methods
Interface: the method by which a user interacts with the information system
Common interaction methods
Command line
Menu
Form
Object-based
Natural language

8. Command Line Interaction
Users enter explicit statements into a system to invoke operations
Example from MS DOS:
COPY C:PAPER.DOC A:PAPER.DOC
This copies a file from the C: drive to the A: drive
Includes keyboard shortcuts and function keys

9. Interface Methods
Interface: the method by which a user interacts with the information system
Common interaction methods
Command line
Menu
Form
Object-based
Natural language

10. Menu Interaction
A list of system options is provided and specific command is invoked by user selection of a menu option
Two common menu types:
Pop-up: menu placed near current cursor position
Drop-down: access point to menu placed at top line of display, menu drops down when access point clicked

14. Guidelines for Menu Design
Wording: meaningful titles, clear command verbs, mixed upper/lower case
Organization: consistent organizing principle
Length: all choices fit within screen length
Selection: consistent, clear and easy selection methods
Highlighting: only for selected options or unavailable options (gray text)

16. Good Menu Design

17. Visual editing tools help designers construct menus.

18. Interface Methods
Interface: the method by which a user interacts with the information system
Common interaction methods
Command line
Menu
Form
Object-based
Natural language

19. Form Interaction
Allows users to fill in the blanks when working with a system
Measures of an effective design:
Self-explanatory title and field headings
Fields organized into logical groupings
Distinctive boundaries
Default values
Displays appropriate field lengths
Minimizes the need to scroll windows

21. Interface Methods
Interface: the method by which a user interacts with the information system
Common interaction methods
Command line
Menu
Form
Object-based
Natural language

22. Object Interaction
Symbols are used to represent commands or functions.
Icons:
Graphic symbols that look like the processing option they are meant to represent
Use little screen space
Can be easily understood by users

24. Interface Methods
Interface: the method by which a user interacts with the information system
Common interaction methods
Command line
Menu
Form
Object-based
Natural language

25. Natural Language Interaction
Inputs to and outputs from system are in a conventional speaking language like English
Based on research in artificial intelligence
Current implementations are tedious and difficult to work with, not as feasible as other interaction methods

26. Hardware Options for System Interaction
Keyboard
Mouse
Joystick
Trackball
Touch Screen
Light Pen
Graphics Tablet
Voice

27. Usability Problems with Hardware Devices
Visual Blocking (device blocks display when using)
touch screen, light pen
User Fatigue (potential for fatigue over long use)
Movement Scaling (device movement translates to equivalent screen movement)
keyboard, mouse, joystick, trackball, graphics tablet, voice
Durability (need for maintenance)
trackball, touch screen
Adequate Feedback (device provides adequate feedback)
keyboard, mouse, joystick, trackball, graphics tablet, voice
Speed (cursor movement)
keyboard
Pointing Accuracy (ability to precisely direct cursor
joystick, touch screen, light pen, voice

29. Designing Interfaces
Use standard formats similar to paper-based forms and reports
Left-to-right, top-to-bottom navigation
Flexibility and consistency:
Free movement between fields
No permanent data storage until the user requests
Each key and command assigned to one function

30. Structuring Data Entry
Never require data that are already online or that can be computed
Defaults
Always provide default values when appropriate
Units
Make clear the type of data units requested for entry
Replacement
Use character replacement when appropriate
(by looking up a value in a table, or automatic filling the rest of a word)
Captioning
Always place a caption adjacent to fields
Format
Provide formatting examples (like $ or decimal point)
Justify
Automatically justify data entries
Help
Provide context-sensitive help when appropriate

31. Entering Text

32. Controlling Data Input
Objective: reduce data entry errors
Common sources data entry errors in a field:
Appending: adding additional characters
Truncating: losing characters
Transcripting: entering invalid data
Transposing: reversing sequence of characters

33. Types of Validation Tests
Class or Composition
Type check
Combinations
Check if reasonable,
E.g.: quantity of sold + type of product?
Expected Values
E.g. Match with existing customer
Missing Data
E.g. All fields of a record
Pictures/Templates
Standard format, E.g.hyphens …

34. Range Reasonableness Self-checking Digits Size Values For situation
9 digit ID
Values
Come from set of standards: Two-letter state code

35. Feedback Messages
Status information: keep user informed of what’s going on, helpful when user has to wait for response
Prompting cues: tell user when input is needed, and how to provide the input
Warning or Error: inform user that something is wrong, either with data entry or system operation

36. Providing Help Place yourself in user’s place when designing help
Guidelines:
Simplicity
Help messages should be short and to the point
Organize
Information in help messages should be easily absorbed by users
Show
It is useful to explicitly show users how to perform an operation

37. What is a Dialogue?
A sequence of interactions between the system and a user
Dialogue design involves:
Designing a dialogue sequence
Building a prototype
Assessing usability

38. Guidelines for Dialogue Design
Consistency
Shortcuts and Sequence
Feedback
Closure (clear start, and end)
Error Handling
Reversal
Control
Ease

39. Dialogue Diagramming
A formal method for designing and representing human-computer dialogues using box and line diagrams

40. Dialogue diagrams depict the sequence, conditional branching, and repetition of dialogues.

41. Designing Interfaces and Dialogues in Graphical Environments
Become an expert user of the GUI environment.
Understand how other applications have been designed.
Understand standards.
Gain an understanding of the available resources and how they can be used.
Become familiar with standards for menus and forms.

43. GUI Window Properties That Can Be Turned On or Off
Modality: require user to finish action before proceeding
Resizable: allow user to change size of window
Movable: allow user to reposition window
Maximize: allow user to make window take entire screen
Minimize: allow user to completely hide window
System menu: allow window to have access to system level functions

44. GUI Dialogue Design Issues
Goal is to establish the sequence of displays that users will encounter when working with system.
Ability of some GUI environments to jump from application to application or screen to screen makes sequencing a challenge.
One approach is to make users always resolve requests for information before proceeding.
Dialogue diagramming helps analysts better manage the complexity of designing graphical interfaces.

45. Summary In this chapter you learned how to:
Explain the process of interface and dialogue design.
Contrast and apply methods for interacting with a system.
List and describe various input devices and factors affecting their usability.
Describe guidelines for designing interface layout, data entry field structure, feedback, and system help.
Design graphical user interfaces.