Here are my arguments for not using caption icons that duplicate the functionality available in right-click.
Note: I realize there are some limitations in the Ajax client prior to V9 that may require icons. My comments are directed at V9+.
- The redundancy and visual clutter waste screen space and distract from the data. If you are a fan of Edward Tufte's work, you'll recognize this as "low Data-ink ratio" and "Chartjunk".
- They deemphasize icons that may be unique and important to a specific chart. These are things you want the user to notice, for example Help or Fast Change.
- They force the designer to display a Caption even when a Caption is not desirable for the layout.
- They keep users ignorant of the full power available, leading them to believe that they are limited to the functions offered by the displayed icons. Have you ever received a change request like "Please add the export to Excel function to chart X so we can export it."?
- Also on the ignorance theme, users don't become aware of new functionality if you don't add the new icons.
Comments and counter arguments welcome.