As a rule, I prefer to be explicit and obvious about functions in our products, specifically iOS apps.

I first heard the term "pawing" in reference to UI design when Lion introduced vanishing scroll bars as first seen in iOS. One pundit referred to the act of pulling and pushing on the view in order to see if there is more content as pawing. It wasn't (isn't) obvious that a window or page can be scrolled to reveal more content if there is no visible scroll bar, unless some content can be seen peaking above the fold. Users were left to paw at windows and pages in order to see if there was any more content.

Being the default in iOS and now OS X, we can't do much about vanishing scroll bars. We can, however, ensure that we don't force users to paw at our apps in order to discover core functionality.

One example is in Message Finder. It's not obvious that swiping left reveals a list of senders. The little dots at the bottom help, but I don't think they're obvious. We can do better. If we moved the refresh and settings buttons to the bottom bar, we could free up that space in the top bar for a Senders button on the right that points to the right. When in the Senders view, we could then place a Categories button on the left that points to the left, back to the Categories page. That would make very clear what options the user has for searching through email.

I realize Message Finder was not originally designed by this team and may have a lot of bad code to be dealt with, so I'm not suggesting we try to make any big design changes right before a release. I just wanted to start a conversation about how we approach the design of our apps.