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Characteristics of Good Interfaces

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Outline

Four characteristics of a good user interface: Consistency Use of hierarchy and grouping Explicitly shows states and state changes Avoids overload

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Consistency

Interface components and layout should be consistent within and across applications

Consistency refers to… Presence and absence of features Physical location of features Appearance of features (widgets, text, icons) Method of accessing features

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Presence and Absence of FeaturesWord:

Customize keyboard

Power Point:

Can’t customize keyboard

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Recently usedfile list

Word

Presence and Absence of Features (2)

Not available

StatView

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Power Point:

Word:

Last entryin list

First entryin list

Physical Location of Features

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Windows:

Windows is searchingfor a file

Windows is searchingfor a file

Appearance of Features

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Consistent (i.e., same) size within a group is aesthetically pleasing

Appearance of Features (2)

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Method of Accessing FeaturesWord:

From INSERT menu:

From VIEW menu:

Two ways to insert page numbers!Are they the same?

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Method of Accessing Features (2)

Application on the desktop:launch by double click

Application on the toolbar:launch by single click

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Outline

Four characteristics of a good user interface: Consistency Use of hierarchy and grouping Explicitly shows states and state changes Avoids overload

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Hierarchy and Grouping

Make relationships obvious Provide “headings” to categorize groups of

related items Use

Horizontal separators Borders Labeled borders Alignment

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Hierarchy isambiguous

ICQ:

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Good sense ofhierarchy and groupings via labeled borders

Yamaha OPL Sound Driver:

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Outline

Four characteristics of a good user interface: Consistency Use of hierarchy and grouping Explicitly shows states and state changes Avoids overload

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States and State Changes

The user must Know the state of the system at all times Be informed of state changes

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Caps Lock State

If would be nice if Caps Lock were indicated!

Caps Lock

What if Caps Lock is on?

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Click here

Eudora:StateChanges

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Click here

Notes:1. Compromise:

Bad: position changesGood: all entries appear

2. Animation helps

Eudora:

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State Uncertainty

Cable modem…

POWER CABLE PC TEST RD TD

Receive Data(from where?)

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What is “Receive Data”?

Cable Modem

My PC

Network Server

Receive data

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Outline

Four characteristics of a good user interface: Consistency Use of hierarchy and grouping Explicitly shows states and state changes Avoids overload

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Overload

From Miller’s famous essay…

Refers to the number of items a human can reasonably process at once

Miller, G. A. (1956, March). The magical number seven plus or minus two: Some limits on our capacity for processing information. The Psychological Review, 63(2), 81-97.

The magical number seven plus or minus two!

Reference:

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Too much to digest without groupings

Eudora:

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Colour Overload!

The following people are "offline"

Painted in red to indicate"offline" (but we alreadyknow that!)

ICQ:

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Why is this blue?

Why is this purple?

Why is this yellow?

ICQ:

Colour Overload! (2)

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Good use ofcolour

Eudora:

Colour Overload! (3)

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Color Design Guideline

Color is good for distinguishing things, but not necessarily for coding things.(People have trouble remembering the association of colors to meanings.)

Design your interface in black and white. Add color for emphasis when your design is complete.

Always honor the system color settings. Keep in mind that 5% of males have some degree

of color blindness.

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Coffee Maker on/off SwitchOn or off? On or off?

Discussion:On the left, the switch appears similar to a North American wall switch in the up, or on, position, whereas the reverse observation applies for the picture on the right. However, the label 0 appears above the label 1. So, some confusion exists. The top part of the switch is immediately beside the label 0; so, perhaps pushing the top part of the switch is associated with the label 0. Also, the use of the colour red may be misleading. Does red mean on or off? When colour is used, sometimes red/green pairs exist, typically with green implying on and red implying off.

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No Confirmation

Click here to “save Windows location” (for next ftp login)

Then what?

Are the changes saved?

WS-Ftp:

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What Do I Do Now?

Where?

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Thank you