UI Terminology: Logon vs Login [closed]

Question

I am crafting an application and cannot decide whether to use the terms Login/out or Logon/off. Is there a more correct option between these two? Should I use something else entirely (like "Sign on/off").

In terms of usability, as long as I am consistent it probably doesn't matter which terms I choose, but I did wonder about the origins of the terms - and whether one or another makes more grammatical sense. I also care deeply about the application I am creating, and want to take the time to investigate all aspects of its user experience.

Answer 1

Since you're looking for correctness,

login, logout, logon, and logoff are all nouns:

"Please enter your login credentials." "I see three logons but only two logoffs from this user." 

The corresponding verbs are each two words:

"Please log in to see your reputation." "You must log off and talk to a human." 

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Update: according to dictionary.com, the various definitions of login are all nouns and involve gaining access to a computer or computer service. Interestingly, logon redirects to login as an exact equivalent. Have the definitions evolved?

Answer 2

Voice of democracy: term / number of google results:

 login    2,020,000,000 sign in    430,000,000 logon       27,700,000 log on      18,200,000 

 logout      83,500,000 log out     34,500,000 sign out    19,400,000 log off      5,350,000