Just looking for some suggestions or best practice thoughts... If a user logs in and the site displays a welcome message, is "Hello, John" better than "Hello, John Doe?"
Displaying the only first name seems more personal, but the full name might seem more "professional."
Both are perfectly valid options, so a lot of it will come down to the feeling you want a user to have when being greeted by the site:
You are right that just the first name is a very personal approach. This is the sort of thing you find with a lot of voice assistants on phones; not only do they simply refer to you by your first name, they can also be customized. It makes the user feel like they have an honest connection to what is actually just a machine.
If your site is for professionals who need to get work done, it may be a good idea to keep it detached and professional. It can help establish a mental barrier that the place a user is now (your site) is a place for getting things done.
To me this is depending on two factors:
The target group:
- For older / more serious customers I would probably go for Hello [First Name] [Last Name].
- For younger / less serious customers I would probably go for Hello [First Name].
The websites goals:
- For some sort of sales website I would probably go for Hello [First Name] [Last Name].
- For some sort of community website I would probably go for Hello [First Name].
Using first name and last name (in English at least) sounds a little crazy.
I have very rarely heard people use that format in real life, it generally only crops up in the movies with science fiction robots/aliens and Soviet-era Russians (do Russians typically do that these days? I have no idea).
Real world occasions with that format...celebrities of course....more down to earth...when a peer group has 2 girls named Anne and has to distinguish between them? Perhaps on occasion when people in a company are referring to upper management (out of respect? because he is a far away figure far more connected to the lives of pro sportsmen than themselves? To avoid CEO Darren Green being mixed up with Darren Brown, the intern?)
In the modern English speaking world I would very much say to go for first name only. I have worked on systems for some very serious major companies and the standard order with them these days is that everyone gets their first name. Nobody gets "Mr Jones" anymore; though as mentioned upper management may get the full name treatment, albeit not to their face.
Mr/Mrs/Ms/Whatever surname....well there you have the problem of there being so many different possible titles. And it all sounds rather artificial and fake. Modern society tends not to like the fake hierarchy this seems to indicate.
Things are different in other countries of course. In Japan you call even your closest co-workers surname-san (unless they are foreign), in Thailand it is Mr. Firstname. But we're on about an English system so lets use English conventions.
Irrelevant to the question but worth mentioning of course is that this name should be come to naturally. If somebody is logged into a system that has a perfectly good reason to know their name. Don't prompt "Enter your name please", "Thanks Jane" purely to add 'personalisation', the Starbucks trend to superfluously throw about somebody's name for pop-psychology reasons is quite the annoyance.