10-2 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. Learning Objectives
10-4 Interface An Interface is the common boundary between the user and the System Applicationthe point where the computer and individual interact.
10-5 Interface Layout Structuring data entry Controlling data input (validation and format controls) Feedback (prompting, status, warning, and error messages)
10-6 Purpose Of Interface Tell The System What Action To take. Select Processing Actions; enter, change, or retrieve data; move between system functions. Facilitate Use Of The System. Allow Users To Accomplish Processing Actions Or Activities Efficiently And Effectively. Avoid Users Errors. Prevent The Taking Of Any Action That Will Create A Processing Error Or Interrupt The Expected Actions Of The Computer System.
10-7 Interface (Input and Output) Design Is An Iterative Process design implementevaluate
10-8 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
10-9 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.
10-10 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.
10-13 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
10-16 Visual editing tools help designers construct menus.
10-17 Processing Action..! In Our Design, We have to Include Ways To Let The User Know How To Take Each Of The Following. Data Entry: The Input Of Data, Using Any Of Several Data Entry Methods; Includes a Description Of Each Data Item And Its Position On Display Screen. The System Must Show The User Which Data Item It Is Addressing As Each Character Is Entered.
10-19 …..! Data Editing: Changing A Previously Entered Data Item. The System Must Indicate Which Data Items On Display Screen Are In Edit Mode(I,e., can be changed) at a certain moment. Data Storage: The Transfer Of Data From The Active Input Area To Storage devices Such As Magnetic Disk, Tape, etc.
10-20 Data 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
10-21 Types of Validation Tests Class or Composition Combinations Values Missing Data Pictures/Templates Size/Range
10-22 Feedback Messages Status information: keep user informed of whats 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
10-23 Providing Help Place yourself in users 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
10-24 What is a Dialogue? A sequence of interactions between the system and a user. A dialog box is a secondary window that allows users to perform a command, asks users a question, or provides users with information or progress feedback.
10-25 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.
10-27 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
10-28 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.