An interesting case study and checklist by Helen Lippel about the use of A-Z Index at the BBC website – read the full article here:
The ABCs of the BBC: A Case Study and Checklist

The 2005 story includes a brief description on personas and design concepts for the project, as well as an “eight-point checklist for creating terrific A-Z indexes”.

Thanks to a tip from SIG-IA Digest.