We have a control to define a distance between 2 objects. This distance can either be absolute (2 in, 15mm, ...) or relative (50 %, ...). The control behaves differently when working with units (automatic conversion) or percentages. Problems arise when the value is taken from a database. The unit is not provided (default is taken). In this case the task should know upfront whether the value is absolute or relative. So the user has to choose between relative/absolute. Does someone knows more elegant names for relative/absolute? Suggestions highly appreciated!
If you don't have any other relative units other than percentage then I would use the words percentage and number to denote relative and absolute respectively.
Hopefully people will understand that percentage will always be relative.
I had the same question on a project and we choose to display both informations.
The user didn't want to think about the information the most valuable for him before to choose one, he just wanted to see it and both relative and absolute distance were useful to him.
Does the percentage has to be shown ? Because you can also display it as a slider, so the user have an accurate measure and a visual estimation of the relative size.