3461 Characteristics of Good Interfaces

3461 Outline  Four characteristics of a good user interface:  Consistency  Use of hierarchy and grouping  Explicitly shows states and state changes  Avoids overload

3461 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

3461 Presence and Absence of Features Word: Customize keyboard Power Point: Can’t customize keyboard

3461 Recently used file list Word Presence and Absence of Features (2) Not available StatView

3461 Power Point: Word: Last entry in list First entry in list Physical Location of Features

3461 Windows: Windows is searching for a file Appearance of Features

3461  Consistent (i.e., same) size within a group is aesthetically pleasing Appearance of Features (2)

3461 Method of Accessing Features Word: From INSERT menu: From VIEW menu: Two ways to insert page numbers! Are they the same?

3461 Method of Accessing Features (2) Application on the desktop: launch by double click Application on the toolbar: launch by single click

3461 Outline  Four characteristics of a good user interface:  Consistency  Use of hierarchy and grouping  Explicitly shows states and state changes  Avoids overload

3461 Hierarchy and Grouping  Make relationships obvious  Provide “headings” to categorize groups of related items  Use  Horizontal separators  Borders  Labeled borders  Alignment

3461 Hierarchy is ambiguous ICQ:

3461 Good sense of hierarchy and groupings via labeled borders Yamaha OPL Sound Driver:

3461 Outline  Four characteristics of a good user interface:  Consistency  Use of hierarchy and grouping  Explicitly shows states and state changes  Avoids overload

3461 States and State Changes  The user must  Know the state of the system at all times  Be informed of state changes

3461 Caps Lock State If would be nice if Caps Lock were indicated! Caps Lock What if Caps Lock is on?

3461 Click here Eudora: State Changes

3461 Click here Notes: 1. Compromise: Bad: position changes Good: all entries appear 2. Animation helps Eudora:

3461 State Uncertainty  Cable modem… POWER CABLEPC TEST RD TD Receive Data (from where?)

3461 What is “Receive Data”? Cable Modem My PC Network Server Receive data

3461 Outline  Four characteristics of a good user interface:  Consistency  Use of hierarchy and grouping  Explicitly shows states and state changes  Avoids overload

3461 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), The magical number seven plus or minus two! Reference:

3461 Too much to digest without groupings Eudora:

3461 Colour Overload! The following people are "offline" Painted in red to indicate "offline" (but we already know that!) ICQ:

3461 Why is this blue? Why is this purple? Why is this yellow? ICQ: Colour Overload! (2)

3461 Good use of colour Eudora: Colour Overload! (3)

3461 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.

3461 Coffee Maker on/off Switch 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.

3461 No Confirmation Click here to “save Windows location” (for next ftp login) Then what? Are the changes saved? WS-Ftp:

3461 What Do I Do Now? Where?

3461 Thank you