Board Thread:The Panopticon/@comment-9435571-20140927221308/@comment-9435571-20141005184131

Adam was taken reluctantly because Rose asked the Doctor to take him along. And then booted after only one adventure. That's less than you could say about Courtney. We also classify Thomas Brewster as a companion despite him starting with stealing the TARDIS and generally getting the Doctor and himself into trouble...

And what makes her less of a companion than Chang Lee?