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Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19981
User Interface Design and Prototyping
Introduction
The chapter will address the following questions: Which features on available terminal and microcomputer displays
can be used for effective user interface design? What are the backgrounds and problems encountered by different
types of terminal and microcomputer users? How do you design and evaluate the human engineering in a user
interface for a typical information system? How do you apply appropriate user interface strategies to an
information system? How do you use a state transition diagram to plan and coordinate a user interface for an information system?
How can prototyping can be used to design a user interface.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19982
User Interface Design and Prototyping
Styles of User Interfaces
Introduction User interface design is the specification of a conversation
between the system user and the computer. This conversation generally results in either input or output --
possibly both.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19983
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection The menu selection strategy of dialogue design presents a list of
alternatives or options to the user. The system user selects the desired alternative or option by keying in the number or letter that is associated with that option. More sophisticated technology allows menu selection by
touching the screen, or selecting menu options with a pen, mouse, cursor keys, or other pointing devices.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19984
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Menu Bars:
Menu bars are used to display horizontally across the top of the screen/window a series of choices from which the user can select.
• The choices typically correspond to commands or properties that the user can select or toggle.
• The choices themselves are typically organized from left-to-right on the basis of the frequency that a choice is selected.
Menu bars are used to identify common and frequently used actions that take place in a wide variety of different windows that make up the application.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19985
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Menu Bars:
Menu bars advantages:• Always being readily visible to the user
• Consistently located
• Easily selected via the keyboard or mouse Menu bars disadvantages:
• Menu choices are organized for left-to-right scanning.
– Studies have shown that users can more easily browse and select from a list that is vertically arranged.
– To aid in clearly scanning the list, adequate spacing between choices is necessary.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19986
User Interface Design and Prototyping
Menu Bar
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19987
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Pull-Down Menus:
Pull-down menus provide a vertical list of choices to the user. A pull-down menu is made available once the user selects a
choice from a menu bar. The list of choices are typically organized from top-to-bottom
according to the frequency in which they are chosen One special type of pull-down menu is called a tear-off menu.
• With a tear-off menu, the user can select the menu and drag to relocate it elsewhere on the screen.
• The tear-off menu is then available for continual referencing.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19988
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Pull-Down Menus:
Pull-down menu advantages:• Allows the designer to simplify a menu bar that may otherwise
contain too many choices.
– Related set of choices are “grouped” into its own separate list.
• Pull-down menu items can be selected via the keyboard or mouse.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 19989
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Pull-Down Menus:
Pull-down menu disadvantages:• The user is not provided with a visual clue that suggests the menu
exists.
• Pull-down menu may obstruct the user’s view of other areas of interest appearing within the body of the screen/window.
• A choice appearing on a pull-down menu may result in yet another list or menu of choices.
– Choices which have a a right-pointing arrow next to the label result in a cascading menu.
– Choices which have an eclipse next to the label result in a dialogue box being displayed that contains commands and properties for the user to complete a task.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199810
User Interface Design and Prototyping
Pull-down Menu
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199811
User Interface Design and Prototyping
Dialogue Box
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199812
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Cascading Menus:
A cascading menu is a menu that must be requested by the user from another higher-level menu.
The cascading menu’s existence is suggested by the visual clue of a right-pointing arrow appearing next to the higher-level menu choice.
When requested, the menu list will appear to the immediate right (in some cases, to the left) of the selected choice from the higher-level menu.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199813
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Cascading Menus:
Cascading menu advantages:• Cascading menus simplify higher-level menus into a smaller set of
related group of choices.
• Vertical arrangement of the choices also makes scanning the choices easier.
Cascading menu disadvantages:• Menu must be requested by the user.
• User may have to traverse several levels of menus to locate and select a desired option.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199814
User Interface Design and Prototyping
Cascading Menu
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199815
User Interface Design and Prototyping
Cascading Menu
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199816
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Pop-up Menus:
A pop-up menu is a vertical listing of choices that must be requested by the user.
A pop-up menu is requested by clicking the right mouse button.
Unlike pull-down and cascading menus, the pop-up menu’s appearance depends on where the pointer was located when the menu was requested.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199817
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Pop-up Menus:
Pop-up menu advantages: • Provide a list of options that pertain to a specific object that the
user selected.
– When the cursor is positioned over an object of interest and the right mouse button is clicked, a pop-menu containing commands or properties pertaining to that object appears in the vicinity of the object.
• Allows the user to obtain a list of actions without changing their focus away from the object or work area on the screen.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199818
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Pop-up Menus:
Pop-up menu disadvantages:• No visual clue that suggests their existence.
• Users must learn about the existence pop-up menus.
• May obstruct portions of the viewing area of interest to the user.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199819
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199820
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Iconic Menus:
An iconic menu uses graphic representations for menu options.• These types of menus are typically used to present the user with
options that pertain to special functions that can be performed within the application.
Iconic menu advantages:• Easy recognition of options.
– The use of graphic images helps the user to memorize and recognize the functions available within an application.
• The choice presented in the form of an icon also provide a relatively larger selection target than the previously discussed menus.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199821
User Interface Design and Prototyping
Styles of User Interfaces
Menu Selection Iconic Menus:
Iconic menu disadvantages:• May be difficult to find or create meaningful graphic images.
• Not everything can easily be represented as a picture.
• What is a readily identifiable and meaningful picture to one person may not be to the next person.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199822
User Interface Design and Prototyping
Iconic Menu
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199823
User Interface Design and Prototyping
Styles of User Interfaces
Instruction Sets Instead of menus -- or in addition to menus – applications can be
designed using a dialogue around an instruction set (also called a command language interface). Users must learn the syntax of the instruction set and this
approach is suitable only for dedicated users. There are three types of syntax.
• A form of Structured English can be defined as a set of commands that control the system.
• A mnemonic syntax is built around meaningful abbreviations for all commands.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199824
User Interface Design and Prototyping
Styles of User Interfaces
Instruction Sets There are three types of syntax. (continued)
• Natural language syntax is when the system user enters commands using natural English (either conversational or formal, written English).The system interprets these commands against a known syntax and requests clarification if it doesn't understand what the user wants. As new interpretations become known, the system learns the system user's vocabulary by saving it for future reference.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199825
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199826
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199827
User Interface Design and Prototyping
Styles of User Interfaces
Question-Answer Dialogues Question-answer dialogue strategy is an style that was primarily
used supplement either menu driven or syntax-driven dialogues. This strategy involves the system asking the system user
questions. The simplest questions involve yes or no answers. This strategy requires that you make sure to consider all
possible correct answers and deal with the actions to be taken if incorrect answers are entered.
Question-answer dialogue is difficult because you must try to consider everything that the system user might do wrong!
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199828
User Interface Design and Prototyping
Question
Answer
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199829
User Interface Design and Prototyping
Styles of User Interfaces
Direct Manipulation Allows direct manipulation of graphical objects appearing on a
screen. This user interface style focuses upon using icons, small graphic
images, to suggest functions to the user. Selecting the icon with a pointing device like a mouse or light pen
executes the function. Icons can work in conjunction with one another.
A pointing device can be used to drag the icon of a file folder (representing a named file) to a trash can icon — intuitively instructing the system to delete (or throw away) the file.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199830
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199831
User Interface Design and Prototyping
Human Factors for User Interface Design
Introduction System users can be broadly classified as either dedicated or
casual. A dedicated system user is one who will spend considerable
time using specific programs. This user is likely to become more comfortable and familiar with the terminal or PC's operation.
The casual system user may only use a specific program on an occasional basis. This user may never become truly comfortable with the terminal or the program.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199832
User Interface Design and Prototyping
Human Factors for User Interface Design
General Human Engineering Guidelines Guideline 1: The system user should always be aware of what to
do next. Tell the user what the system expects right now. Tell the user that data has been entered correctly. Tell the user that data has not been entered correctly. Explain to the user the reason for a delay in processing. Tell the user that a task was completed or was not completed.
Guideline 2: The screen should always be formatted so that the various types of information, instructions, and messages always appear in the same general display area.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199833
User Interface Design and Prototyping
Human Factors for User Interface Design
General Human Engineering Guidelines Guideline 3: Messages, instructions, or information should be
displayed long enough to allow the system user to read them. Guideline 4: Use display attributes sparingly. Guideline 5: Default values for fields and answers to be entered
by the user should be specified. Guideline 6: Anticipate the errors users might make.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199834
User Interface Design and Prototyping
Human Factors for User Interface Design
Dialogue Tone and Terminology The overall tone and terminology of a dialogue are important and
the session should be user friendly. With respect to the tone of the dialogue, the following guidelines
are offered: Use simple, grammatically correct sentences. Don't be funny or cute! Don't be condescending; that is, don't insult the intelligence of
the system user.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199835
User Interface Design and Prototyping
Human Factors for User Interface Design
Dialogue Tone and Terminology With respect to the terminology used in the dialogue, the
following guidelines are offered: Don't use computer jargon. Avoid most abbreviations. Use simple terms. Be consistent in your use of terminology.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199836
User Interface Design and Prototyping
Human Factors for User Interface Design
Dialogue Tone and Terminology With respect to the terminology used in the dialogue, the
following guidelines are offered: (continued) Instructions should be carefully phrased, and appropriate
action verbs should be used. • The following recommendations should prove helpful:
– Try SELECT instead of PICK when referring to a list of options.
– Use TYPE, not ENTER, to request the user to input specific data or instructions.
– Use PRESS, not HIT or DEPRESS, to refer to keyboard actions.
– When referring to the cursor, use the term POSITION THE CURSOR, not POINT THE CURSOR.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199837
User Interface Design and Prototyping
Display Features That Affect User Interface Design
Display Area The size of the display area is critical to user interface design. For terminal displays, the two most common display areas are 25
(lines) by 80 (columns) and 25 by 132. For microcomputer and workstation display monitors, display size
is measured in pixels. The greater the number of pixels, the more information can be
displayed. Pixel display areas are specified in width by height.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199838
User Interface Design and Prototyping
Display Features That Affect User Interface Design
Character Sets and Graphics Every display uses a predefined character set. Most displays use the common ASCII character set. Some displays allow the programmer to supplement or replace the
predefined character set. Most displays today offer graphics capabilities.
Graphics capabilities must be supported by graphics controllers and software that allow the programmer to take advantage of the graphics capabilities.
Graphics-based displays may support a virtually unlimited character set.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199839
User Interface Design and Prototyping
Display Features That Affect User Interface Design
Paging and Scrolling The manner in which the display area is shown to the user is
controlled by both the technical capabilities of the display and the software capabilities of the computer system. Paging displays a complete screen of characters at a time. The
complete display area is known as a page (also called a screen or frame). The page is replaced on demand by the next or previous page.
Scrolling moves the displayed characters up or down, one line at a time.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199840
User Interface Design and Prototyping
Display Features That Affect User Interface Design
Display Properties Most displays in use today provide a wide variety of display
properties that may be manipulated to more effectively present data and information.
Display properties are characteristics that change the way in which a character or group of characters is displayed on a screen.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199841
User Interface Design and Prototyping
Display Features That Affect User Interface Design
Split-Screen and Windowing Capabilities Split-screen capability is a variation on the windows concept. The display screen, under software control, can be divided into
different areas (called windows). Each window can act independently of the other windows,
using features such as paging, scrolling, display attributes, and color.
Each window can be defined to serve a different purpose. Windows can be resized, moved, and hidden or recalled on user demand.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199842
User Interface Design and Prototyping
Display Features That Affect User Interface Design
Keyboards and Function Keys Most modern terminals and monitors are integrated with
keyboards. The number of keys and their layout may vary, but most
keyboards contain special keys called function keys.• Function keys (usually labeled F1, F2, and so on) can be used to
implement certain common, repetitive operations in a user interface (for example, START, HELP, PAGE UP, PAGE DOWN, EXIT). These keys can be programmed to perform common functions.
Function keys should be used consistently. • A system's programs should consistently use the same function
keys for the same purposes.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199843
User Interface Design and Prototyping
Display Features That Affect User Interface Design
Pointer Options There are many selection options, such as touch-sensitive screens,
voice recognition, and pointers. The most common pointer is the mouse.
• A mouse is a small hand-sized device that sits on a flat surface near the terminal. It has a small roller ball on the underside. As you move the mouse on the flat surface, it causes the pointer to move across the screen. Buttons on the mouse allow you to select objects or commands to which the cursor has been moved. Alternatives include trackballs, pens, and trackpoints.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199844
User Interface Design and Prototyping
How to Design & Prototype a User Interface
Step 1: Chart the Dialogue A state transition diagram is used to depict the sequence and
variations of screens that can occur when the system user sits at the terminal (PC or workstation). Rectangles are used to represent display screens. The arrows represent the flow of control and triggering event
causing the screen to become active or receive focus. The rectangles only describe what can appear during the
dialogue. The direction of the arrows indicate the order in which these
screens occur.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199845
User Interface Design and Prototyping
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Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199846
User Interface Design and Prototyping
How to Design & Prototype a User Interface
Step 2: Prototype the Dialogue and User Interface Many screens may have to be designed and prototyped.
Some screens were identified for the purpose of bringing together the application and its input and output screens.
Some screens were identified for the purpose to provide the user some flexibility with customizing the application’s interaction to suit their own preferences.
Other screens may have been identified to deal with system controls such as backup and recovery.
It is through studying the entire collection of screens that you may discover the need to make revisions to some screens.
It is likely that such issues as color, naming consistencies of common buttons and menu options, and other look-and-feel conflicts may need to be resolved.
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199847
User Interface Design and Prototyping
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Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199848
User Interface Design and Prototyping
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3
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Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199849
User Interface Design and Prototyping
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Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199850
User Interface Design and Prototyping
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Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199851
User Interface Design and Prototyping
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Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199852
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199853
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199854
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199855
User Interface Design and Prototyping
Prepared by Kevin C. Dittman for
Systems Analysis & Design Methods 4ed
by J. L. Whitten & L. D. BentleyCopyright Irwin/McGraw-Hill 199856
User Interface Design and Prototyping
How to Design & Prototype a User Interface
Step 3: Obtain User Feedback Exercising (or testing) the user interface is a key advantage of all
prototyping environments. Exercising (or testing) the user interface means that system
users literally experiment with and test the interface design prior to extensive programming and actual implementation of the working system. Analysts can observe this testing to improve on the design.
In the absence of prototyping tools, the analyst should at least simulate the dialogue by walking through the screen sketches with system users.