Darken

Yardley, Monday 3 September 2001
What to do with a screen full of options? Such a screen causes confusion. When is an option valid? Such a GUI is too difficult, too cumbersome to use.

Disable

In a desktop GUI it standard procedure to disable a field, make it inaccessible. See the example below. Click on a radio button and other fields will disable.
EmployeeTerry SchmidtDay 03 Sep 2001
Availability Whole day off Reason
Limitedfrom till
Full day work Morning 07:00 - 11:30
Afternoon 12:00- 15:30
Fields disabled do not make a screen easier to use.
  1. Disabled fields are too subtle. A user must consciously look at a field to realise that it is disabled. Most of the time a user will only notice that a field is dimmed when clicking on it.
  2. Disabled fields block, obstruct. The user is unable to do what he really wants. Disabled fields force the user into a fixed sequence of action: first select the right radio button, then the related details.

    Users just have to guess why the field is disabled. The user will wonder How to regain that option?

  3. Static text incorrectly remains easily readable, like the text at 'Morning' and 'Afternoon'.

Darken

An alternative: Do not disable but darken.
EmployeeTerry SchmidtDay 03 Sep 2001
Availability Whole day off Reason
Limitedfrom till
Full work day Morning 07:00 - 11:30
Afternoon 12:00- 15:30
  1. Set the background colour to grey so the user immediately sees which fields are applicable.
  2. The user is still permitted to click on the darkened fields.
    • The field will light up.
    • The radio button will be selected.
    • Other fields darken.
    Simple yet easy.
  3. It is clear whether the fields at 'Morning' and 'Afternoon' are applicable.
Till next week,
Nut
Special thanks to Terry Schmidt for his javascript research.