Re: [Usability] label alignments

[Anna Marie Dirks <anna ximian com>]

Greetings. Whilst watching this discussion, I've had the distinct feeling that it would benefit from some specific citations (saying "I like it better this way because it looks better to me" is only so relevent to our task here.) I've collected quotes from the mac human interface guidelines, and from 
the java developer's guidelines. Note that neither set of guidelines recommends a singular approach to label alignment. 

 From the macintosh human interface guidelines: http://developer.apple.com/techpubs/mac/HIGOS8Guide
>     " There are three approaches you can take to aligning static text fields when you stack multiple dialog box items to which the fields pertain:
>     
>     You can left align the text fields. This is the standard approach.
>     You can right align the text fields. This is useful when you use colons at the end of the field. 
>     
>     A third approach--left aligning both the text fields and their items--is useful for the rare case in which the fields are nearly the same length. If you are designing your application and its interface for the international market, you should not take this approach because it does not lend itself to localization. " 
The java developer's guidelines:
http://java.sun.com/products/jlf/ed1/dg/higg.htm#67556
>     "Between components, alignment of multiple labels becomes an issue. Aligning labels to a left margin can make them easier to scan and read. It also helps to give visual structure to a block of components, particularly if there is no immediate border (such as a window frame) surrounding them. If labels vary greatly in length, the use of right alignment can make it easier to determine the associated component; however, this practice also introduces large areas of negative space, which can be unattractive. The use of concise wording in labels can help to alleviate such difficulties."
Hope this is helpful. 
Anna

ps. At Ximian, we tend toward left-aligned labels with colons. We favor this approach because it provides a unified starting point for interface elements;  we find that this makes a dialog easier for a left-to-right reader to parse.