[eluser]Kemik[/eluser]
Hello,

Do you use usernames to login to your apps, allowing the change of email addresses (but the email must be unique) or do you use email addresses to login to your apps, allowing the change of usernames?

I'm faced with that dilemma for my new project. Half of the current "like" sites use email as the identifier and allow users to select their own username. As long as the username is unique they allow the change via their "edit profile" page. The user's email can also be changed but must be unique, however email is used to login.

The other half of "like" sites, mainly forums such as vBulletin, PHPBB, etc use usernames. Usernames in these apps cannot be changed, the emails can.

So, what system do you use and why?

[eluser]BizComputing[/eluser]
As a consultant, I usually have to follow what the client chooses.

Personal choice and what I recommend, go with usernames and both username and email are changeable. Internally links to the user are tracked via an arbitrary id, so username only needs to be unique rather than also forcing it to also be locked in.

[eluser]Isern Palaus[/eluser]
Hello Kemik,

When I program something that the only users will be a little group of people i prefer usernames and I allow to them to change their own e-mail (by the way, I've never use it for nothing).

Recently I've programed a website for my high school, then I allow to login students like me with the Fiscal Identification Number (DNI in Spain) or the username that the secretary sets (first name letter and first surname, if It's 2 usernames equal at the second we add a n+1 where N=0).

Now I've in my mind a big site to develop and I'll use e-mails (unique) to login and the username could be changed. Why? Probably because It's not the most important what the username says.

Sorry for my school English.

Regards,
-- Isern Palaus

[eluser]Aea[/eluser]
It should be possible to make both changeable, and personally I would choose to login through a username rather then an email, but it also depends on what you're working for. School/University programs I would choose emails over usernames, but for most other programs I'd go for usernames

[eluser]ejangi[/eluser]
From a usability stand-point the consensus is that a username is an extra piece of information that the user has to remember, so using an email address is preferred.

It also means that there's less to type in on a registration form etc - again making things easier for the user.

[eluser]Michael Wales[/eluser]
If the identifier (whether it be username or email) will be displayed publicly, I always choose username - to combat spam.

If it will not be displayed publicly I always choose email. Every user knows their email address - usernames... I have about 10-15 of them and I can never remember which name I used on which service.

Of course, client's needs always override my choices (although I will present my opinions to see if they change their mind).

[eluser]thurting[/eluser]
OpenID

[eluser]Colin Williams[/eluser]
I tend to go with email because it's easier for users to remember. In the case that an app uses a username (like for public display), I'll probably have the app accept either. One principle in interaction design "never let the user error," so accepting either works out nicely.