Designing the Inputs and User Interface Chapter 12 Designing the Inputs and User Interface

Learning Objectives To become familiar with the various common methods by which end users interact with IS To review the common computer input devices and to explore the newer, more sophisticated input technologies To understand the three basic metaphors for designing human–computer interaction mechanisms

Learning Objectives To understand and be able to apply the basic design guidelines for high quality and usable data entry screens To understand the two categories of input controls, as well as their strengths and limitations

User Interface Methods Command Dialogue Menus Icons and Buttons Input Screens and Forms Natural Language Recognition

Command Dialogue End users initiate all dialogue by issuing instructions to the computer via a structured syntax of command Requires a significant learning curve on the part of the end user

Menus Present the end user with a list of available alternatives Types of menus Single menu approach Hierarchical menu approach Menu bar approach Pop-up menu

Icons and Buttons End user selects and executes commands by pointing and clicking at graphical buttons or icons Easy recognition by end users

Figure 12-2. Iconic Menu Toolbar

Input Screens and Forms Use a screen-based form to get input from users The navigation method should allow the user to move from field to field in a logical, intuitive sequence

Proper navigation Poor navigation Figure 12-3. Examples of Logical and Counterintuitive Navigation Sequences

Voice Recognition Uses voice synthesis technology Allows the user to interface with the computer device by using natural language and voice commands Error rate is decreasing in recent years

Voice Recognition Future development Computer scientists looking for pauses in our voice Speaker independence Understanding of gesture

Voice Recognition Natural Computing Adapt to natural human interaction skills To interpret vocal command To track movement and gestures

Common Input Device Punch Card Biometric Input Devices Automatic identification of a person based on his or her physiological or behavioral characteristics Pattern recognition system

Figure 12-4. Examples of Biometric Input Devices

Common Input Device Optical Input Devices Barcode Provide a simple and easy method of encoding text and numerical information to be read by inexpensive devices A series of parallel, adjacent bars and spaces

Figure 12-5. Barcode Scanner and Barcode Structure

Common Input Device Optical Input Devices OMR Optical Mark Reading Uses an array of light-emitting diodes (LEDs) to scan for marks in certain position Used for questionnaires, tests, voter registration, market research

Figure 12-6. Optical Mark Reader Scan Sheet and Auto-Scanner Skunk Marks Data Scanning Figure 12-6. Optical Mark Reader Scan Sheet and Auto-Scanner

Common Input Device Optical Input Devices OCR Optical Character Recognition Scan virtually any form or document containing numbers, letters, or marks

Figure 12-7. Smart Card Technology

Common Input Device Smart Card A plastic card embedded with an integrated circuit chip Used for payment processing, identification, network computing, health care management

Guidelines for Input and Interface Design HCI Metaphors Desktop or direct manipulation Document Dialogue

The Desktop Metaphor Build on the common set of activities and organizational schemes associated with a common desktop Create an electronic desktop that provides all of the flexibility and advantages of a physical desktop

Figure 12-8. Example of Electronic Desktop Metaphor

The Document Metaphor The end user interacts with the computer by browsing through, or entering data in electronic documents and forms

The Document Metaphor Hypermedia Links graphics, video, and audio together in a manner that allows the users to easily navigate between the documents Hyperlinks bear a strong resemblance to reference in paper documents Filling in forms on web pages is reminiscent of filling in paper forms

The Document Metaphor Disadvantages of desktops Reading machines Do not provide mobility Are not spatial Vary in software Reading machines Encapsulate the physical aspects we are accustomed to when reading from a hard copy

The Dialogue Metaphor Attempt to create an electronic version of a conversation using natural language Electronic Personal Assistant

Data Entry Issue Consistency The methods and functions available on one data entry screen should be consistently applied to all entry screens

Data Entry Issue Standardized Interface Learning curve for an end user is significantly reduced The probability of data entry error across screens is reduced

Table 12-1. Common Data Entry Screen Functions

Table 12-2. Guidelines for Effective Input Screen Design

Data Entry Screen Characteristics Determine default value when appropriate Include context-sensitive help Pop-up help, hotspots, tool tips, etc.

Figure 12-10. Examples of Context-Sensitive Help Mechanisms Tooltip Hotspot Popup Figure 12-10. Examples of Context-Sensitive Help Mechanisms

Providing User Feedback System Status Feedback Users needs to be reassured that the intended process is successfully executing Users need some indication of the estimated length of time for the process to execute or complete System status indicator

Figure 12-11. End User Feedback Using Both Text and Graphics

Providing User Feedback User prompts The designer needs to communicate information to the user in the form of a statement or a selection that is related to either a process in progress or a possible error condition in effect

Figure 12-12. Dialog Box Examples

Dialogue Design Usability Assessment Used to determine the effectiveness and efficiency of the various interface structures and components of the application Surveys, questionnaires, focus groups, field observation

Table 12-3. Guidelines for the Design of Effective HCI Dialogues

Designing the Input Controls Intended to ensure that the data input to the system are both accurate and valid to the highest degree possible Access Control Data Control

Designing the Input Controls Data Control Appending error Truncation error Transcription error Transposition error Design Control Mechanism Table 12-4

Table 12-4. Input Validation Control Mechanisms

Table 12-5. Check Digit Calculation Method

Designing the Input Controls Access Control Authentic Mechanism Authorization Schema Encryption Mechanism

Chapter Summary This and the previous chapter provided a detailed overview of the design and control issues on system input and output. With these two tasks complete, the system is well on its way to completion and implementation.

Chapter 12 End of Chapter