Is it better to ask for 'full name' or 'first name' and 'last name' in a registration form?

Possible Duplicate:
I want to make name input one field instead of first name/Last name. Wise? Worth it?

I want to know that whether full name or first name and last name is better to ask in user profile or registration form?

For example: My full name as per my NIC is Waheed-ud-din, where it is one name, so no separate firstname or lastname. I can use my family name with it, as lastname. But I usually don't use that. I normally use Hafiz as my firstname that is my nick and most people know me with that.

So should we use display name during registration and during profile completion use fullname? It seems good but problem arise when display name and full name are totally different and we need to show fullname at some places and username/displayname at some other places. Some time user can be confuse because of it. What do you think could be the solution?

Answer

You're right, the user definitely could be confused if you're not referring to them in a consistent manner and where you display each definitely needs consideration.

I'd suggest looking at websites that use screen names and full names and how they handle each. Twitter, for example, asks for both on sign up.

Depending what your site is about, it may be ok to just skip a full name all together? If you can't skip it and assuming you need more than a name, consider asking the user for additional information on their first login and explain why you need the info.

Also, if your able to use social network logins, you could pull their full name information without their typing it in.

Bottom line, I suggest you make the sign up process as simple as possible (increasing sign ups) and if you need more info, ask for it later (when they already have a stake in your site) and maybe explain why you need it.