Chapter 12

Balancing Function and Fashion

Outline

 

I.          Introduction

•         User experiences play a critical role in influencing software acceptance

–        Conversational messages have their limits

–        Design needs to be comprehensible, predictable, and controllable

–        Information layout is important

–        Multiwindow coordination

–        Large, fast, high-resolution color displays have potential

 

II.        Error messages

•         Phrasing of error messages or diagnostic warnings is critical, especially when dealing with novices

•         Avoid

–        imperious tone that condemns user

–        messages that are too generic (e.g. WHAT? or SYNTAX ERROR)

–        messages that are too obscure (e.g. FAC RJCT 004004400400)

•         Specificity

 

 Poor

Better

 SYNTAX ERROR

Unmatched left parenthesis

ILLEGAL ENTRY

 Type first letter: Send, Read, or Drop

 INVALID DATA

 Days range from 1 to 31

 BAD FILE NAME

 File names must begin with a letter

 

•         Constructive guidance and positive tone

–        Messages should, where possible, indicate what users should do to correct the problem

–        Unnecessarily hostile messages using violent terminology can disturb non-technical users:

•         FATAL ERROR, RUN ABORTED

•         CATASTROPHIC ERROR: LOGGED WITH OPERATOR

•         Negative terms such as ILLEGAL, ERROR, INVALID, BAD should be eliminated or used infrequently

 

 Poor

Better

 Run-Time error ‘-2147469 (800405): Method ‘Private Profile String’ of object ‘System’ failed.

Virtual memory space consumed.  Close some programs and retry.

Resource Conflict Bus: 00  Device: 03  Function: 01

 Remove your compact flash card and restart

 Network connection refused.

 Your password was not recognized.  Please retype.

 Bad date.

 Drop-off date must come after pickup date.

 

•         User-centered phrasing

•         Appropriate physical format

•         Development of effective messages

–        Recommendations

•         Increase attention to message design

•         Establish quality control

•         Develop guidelines

–        Have a positive tone

–        Be specific and address the problem in the user's terms

–        Place the users in control of the situation

–        Have a neat, consistent, and comprehensible format

•         Carry out usability test

•         Collect user performance data

 

III.       Nonanthropomorphic design

•         Concerns

–        attributions of intelligence, autonomy, free will, etc can deceive, confuse, and mislead users

–        important to clarify differences between people and computers

•         Advocates of anthropomorphic interfaces suggest that they may be most useful as teachers, salespeople, therapists, or entertainment figures

•         An alternative design  is to present a human author of a package through prerecorded audio or video

•         Guidelines

–        Be cautious in presenting computers as people.

–        Design comprehensible, predictable, and controllable interfaces.

–        Use appropriate humans for introductions or guides.

–        Use cartoon characters in games or children’s software, but usually not elsewhere

–        Provide user-centered overviews for orientation and closure.

–        Do not use 'I' pronouns when the computer responds to human actions.

–        Use "you" to guide users, or just state facts.

 

IV.       Display design

•         Effective display designs must provide all the necessary data in the proper sequence to carry out the task

•         Mullet and Sano's categories of design principles:

–        Elegance and Simplicity: unity, refinement and fitness

–        Scale, Contrast, and Proportion: clarity, harmony, activity, and restraint

–        Organization and Visual Structure: grouping, hierarchy, relationship, and balance

–        Module and Program: focus, flexibility, and consistent application

–        Image and Representation: immediacy, generality, cohesiveness, and characterization

–        Style: distinctiveness, integrity, comprehensiveness, and appropriateness

 

V.        Window design

•         Introduction

–        Need to offer users sufficient information and flexibility to accomplish task, while reducing window housekeeping actions, distracting clutter, eye-head movement

•         opening, closing, moving, changing size

•         time spent manipulating windows instead of on task

•         Coordinating multiple windows

•         Image browsing

–        A two-dimensional cousin of hierarchical browsing

–        The design of image browsers should be governed by the users’ tasks,

•         Personal role management

–        A role centered design emphasizes he users’ tasks rather than the applications and documents

 

VI.       Color

•         Guidelines

–        Use color conservatively

–        Limit the number and amount of colors

–        Recognize the power of color to speed or slow tasks

–        Color coding should support the task

–        Color coding should appear with minimal user effort

–        Color coding should be under user control

–        Design for monochrome first

–        Consider the needs of color-deficient users

–        Color can help in formatting

–        Be consistent in color coding

–        Be alert to common expectations about color codes

–        Be alert to problems with color pairings

–        Use color changes to indicate status changes

–        Use color in graphic displays for greater information density