We have all got kind of used to all kinds of things requiring information they have no reasonable need to.
- Eg a forum requiring your phone number, address and occupation.
- A raffle requiring more or less your life-story.
- Almost everything requires you to give your gender, when that has literally nothing to do with the service being offered.
The reason these are asked for is generally pretty obvious -- it is market research. Though I think there is also a aspect of monkey-see monkey-do. Everyone else did it why shouldn't I?
StackExchange (and other things that let you sign-in/up with only a OpenID) are a refreshing change.
Another example, not online, I am part of a organisation that has a requirement for all members to submit a membership form each year when they renew. One of the services our organisation offers is book borrowing. To borrow a book, a book borrowing form must be completed. Now there were two view points on what should be on the borrowing form:
One said, we need the names of the book, the borrow dates, and there name (or organisation is small enough this is a unique identifier), and their address and phone number. Then if we need to track them down because the book is over-due we can track them down and get it back.
The other argument (mine), said that we just need there name, the borrow dates and the book dates -- none of their details. We don't need the details -- they gave those to us when they submitted their membership form. The reasoning behind this is that it would be a better user experience if it was shorter. Thus would be more likely to use the service, and also to actually submit the borrowing form -- instead of just grabbing the book without filling in a form (which has happened alot historically.)
I'm looking for a term to describe this principle in UX design, so I can research it further. The "Minimise information required/obtained from users" principle.
I'm sure there are other side benefits from following the principle, like minimising the amount of privacy concern overhead in tasks (Such as the need for a Clear Desk Policy)