Chapter 18 Designing User Interfaces Systems Analysis and

Chapter 18 Designing User Interfaces Systems Analysis and Design Kendall and Kendall Fifth Edition © Copyright Prentice Hall, 2002

Major Topics n n n n User interfaces Dialogue guidelines Feedback Help Ecommerce dialogue Data mining Ergonomics Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 2

The User Interface n The user interface is the system which helps users communicate with the computer system and/or the application system Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 3

User Interface Design Objectives n To design a better user interface, use the following objectives: n n Effectiveness as achieved through design of interfaces that allow the user to access the system in a way that is congruent with their individual needs Efficiency as demonstrated through interfaces that increase speed of data entry, and reduce errors Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 4

User Interface Design Objectives n Further interface design objectives n n n User consideration as demonstrated in designing suitable interfaces, and providing appropriate feedback to users from the system Generating usable queries Productivity as shown through following sound principles of design for user interfaces and work spaces Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 5

Components of the User Interface n The user interface has two main components n n Presentation language, which is the computer-to-human part of the transaction Action language that characterizes the human-to-computer portion Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 6

Types of User Interfaces n There are several types of user interfaces: n n n Natural-language interfaces Question-and-answer interfaces A menu interface Form-fill interfaces Command-language interfaces Graphical User Interfaces (GUIs) Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 7

Natural-Language Interfaces n Natural-language interfaces permit users to interact with the computer in their everyday or "natural" language Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 8

Question-and-Answer Interfaces n Question-and-answer interfaces n n The computer displays a question for the user on the screen The user enters an answer via the keyboard The computer acts on that input information in a preprogrammed manner New users may find the question-andanswer interface most comfortable Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 9

A Menu Interface n n A menu interface, which provides the user with an onscreen list of available selections A nested menu is a menu which can be reached through another menu Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 10

Advantages of Nested Menus n The advantages of nested menus are n n n Nested menus give a less cluttered screen Nested menus eliminate menu options which do not interest a user Nested menus allow users to move quickly through the program Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 11

Graphical User Interface (GUI) Menus n GUI menus guidelines n n n The main menu is always on the screen The main menu uses single words The main menu should have secondary menus grouped into similar features Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 12

Graphical User Interface (GUI) Menus n Further GUI menus guidelines n n n The secondary drop-down menus often consist of more than one word Secondary options perform actions or display additional menu options Menu items in gray are unavailable for the current activity Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 13

Form-Fill Interfaces n n Form-fill interfaces are onscreen forms displaying fields containing data items or parameters that need to be communicated to the user Form-fill interfaces may be implemented using the Web Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 14

Advantages and Disadvantages of Web Forms n Advantages of using a Web-based form n n n User enters the data Data may be entered 24 hours a day, globally Disadvantages of a Web-based form n n The user may not know what to enter if the form is not clear User might be nervous about using a credit card over the Internet Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 15

Command-Language Interfaces n n Command-language interfaces are more popular than the previous ones Allow the user to control the application with a series of keystrokes, commands, phrases, or some sequence of these Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 16

Graphical User Interfaces (GUIs) n n GUIs provide a strong metaphor of the application Allow direct manipulation of the graphical representation on the screen n n Can be accomplished with keyboard input, joystick, or mouse Requires more system sophistication than other interfaces Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 17

Dialog n n Dialog is the communication between a person and the computer Three key points to be considered n n n Meaningful communication Minimal user action Standard operation and consistency Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 18

Communication n n Communication means that the user understands the information that is being presented Users with less skill require a greater amount of communication Provide easy to use help screens Often these contain hyperlinks to other related help topics Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 19

Minimal User Action n Minimal user action is achieved by n n n Entering codes instead of code meanings Enter only data that are not stored on files Not requiring users to enter editing characters Supplying default values on entry screens Providing inquiry programs with short entry fields Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 20

Minimal User Action n Further key points n n n Providing keystrokes for selecting menu options that are normally selected using a mouse Selecting codes from a pull-down menu on a GUI screen Provide context-sensitive menus, displayed when the right mouse button is clicked on an object Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 21

Standard Operation n Standard operation is achieved by n n Keeping header and footer information in the same locations for all screens Using the same keystrokes to exit a program Using the same keystrokes to cancel a transaction Using a standard key for obtaining help Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 22

Standard Operation n Further key points n n Standardized use of icons when using graphical user interface screens Consistent use of terminology within a screen or Web site Providing a consistent way to navigate through the dialog Consistent font alignment, size, and color on a Web page Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 23

Tab Control Dialogue Boxes n n n Tab control dialog boxes are a feature of GUI design They should have logically grouped functions on each tab Each tab dialog box should have OK, Cancel or Apply, and perhaps Help buttons Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 24

Voice or Speech Recognition n n Voice or speech recognition systems are developing rapidly There are two different types of voice recognition: n n Continuous speech systems, allowing for dictation Speaker independence, so people can enter commands or words at a given workstation Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 25

Evaluating User Interfaces n The five useful standards in evaluating the interfaces are n n The training period for users should be acceptably short Users early in their training should be able to enter commands without thinking about them, or referring to a help menu or manual Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 26

Evaluating User Interfaces n Continued evaluation guidelines n n n The interface should be "seamless" so that errors are few, and those that do occur are not occurring because of poor design Time necessary for users and the system to bounce back from errors should be short Infrequent users should be able to relearn the system quickly Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 27

Feedback n All systems require feedback in order to monitor and change behavior by n n Comparing current behavior with predetermined goals Giving back information describing the gap between actual and intended performance Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 28

Types of Feedback n Feedback to the user is necessary in seven distinct situations: n n n n The computer has accepted the input The input is in the correct form The input is not in the correct form There will be a delay in processing The request has been completed The computer cannot complete the request More detailed feedback is available Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 29

Program Help n Program help comes in a variety of ways: n n Pressing a function key, such as F 1 A GUI pull-down menu Context-sensitive help, specific for the operation being performed Iconic help, obtained when a cursor is left over an icon for a few seconds Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 30

Program Help n Program help options, continued n n n Wizards, which provide a series of questions and answers when trying to perform an operation Telephone help desks provided by the software manufacturer Software forums on nation wide bulletin boards Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 31

Ecommerce Dialog n n Extra considerations are needed when developing ecommerce Web sites Feedback needs to be solicited from customers, using either of two methods: n n Launch the user’s email program Create a blank feedback template with a submit button labeled “feedback” Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 32

Intuitive Navigation for Ecommerce Sites n Intuitive navigation should be designed n n Creating a rollover menu Building a collection of hierarchical links Placing a site map on the home page and emphasizing the link to it from every page on the site Placing a navigational bar on every inside page that repeats the categories used on the entry screen Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 33

Types of Queries n There are six different types of queries: n n Obtain specified data for a particular entity Find a group of entities that have certain characteristics Find attributes for an entity for certain characteristics Display all the attributes for a certain entity Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 34

Types of Queries n Different types of queries (continued): n n Find all entities with a certain characteristic List attributes for all entities for certain characteristics Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 35

Query Notation n V is value, E is entity, A is attributes, variables in parentheses are given: n n n Query Query Kendall & Kendall type type 1: 2: 3: 4: 5: 6: V E A <--<--<--- (E, A) (V, E) (E, all A) (V, all E) Copyright © 2002 by Prentice Hall, Inc. 36

Methods for Implementing Queries n There are two methods for implementing database queries: n n Query By Example (QBE), which allows users to select fields and specify conditions using a grid Structured Query Language (SQL), which uses a series of keywords and commands to select the rows and columns that should be displayed Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 37

Parameter Queries n A parameter query allows users to enter a value to select records without changing the query syntax Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 38

Web Searches n n Web searches use search engines to answer a query Guidelines for searching the Web n n n Decide whether to search or surf the Web Think of the key terms before searching Construct the search questions logically, with attention to the use of AND and OR search logic Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 39

Web Searches n Further guidelines for searching the Web are: n n n Use a search engine that saves your searches Use a search engine that informs you of changes in the Web sites you select Look for new search engines periodically Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 40

Data Mining n n Data mining is gathering a large amount of information about a person and their habits and using that information as a predictor of future behavior It must be carefully and ethically used to avoid infringing on an individual’s privacy Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 41

Ergonomics n Systems analysts should consider an ergonomically sound working environment even though they usually don't have much control over the design of the workspace Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 42

Ergonomics n Some of the important working environmental variables to be considered are n n n Room color and lighting VDT or LCD screens User keyboards Computer desks User seating Kendall & Kendall Copyright © 2002 by Prentice Hall, Inc. 43