The Anatomy of Scrolling
Developing Weekly Retrospect’s UI has got me thinking about a lot of different interactions that I’ve never thought about before, specifically because of the difference between abstract manipulation of content (using a mouse) and direct manipulation of content (using your hand.)
I never quite understood why my grandparents said “Go up” when I used to scroll email or web pages for them (before she learnt how to use a mouse) when she actually wanted me to scroll down. Even my mother’s older sister would also use the terminology of “scrolling up” when she actually meant scrolling down.
I now see that they saw the content moving upwards so they thought it was “going up” when in fact I was moving the “viewport” down. The viewport is what we see at any point in time. When we read a book we move our viewport by looking over to the next page. When we read a newspaper we move the viewport around the the newspaper that we hold in front of us. Very seldom do we see the content moving around within our viewport (unless it is actually moving), instead it is our viewport that moves around the content. So when they see content moving up within their viewport they interpret this not as the viewport itself moving down the page but as the physically content moving upward.
I came across this issue when coding the Natural Human Interface interactions for Weekly Retrospect. Keyboard keys move the viewport around (like traditional scrollers) so a right arrow key will move the “viewport” to the right. To achieve the same effect with a Natural Human Interface we have to come up with an interaction (or gesture) whose effect in reality would mimic what is being shown on screen. As what is been shown on screen looks like content moving from the right of the viewport to the left of the viewport, an appropriate gesture is one which would physically move the content, like dragging from right to left.
So a motion which goes toward the left translates to a keyboard key that points to the right. This isn’t amazing or revolutionary, just something I thought was interesting. An understanding of abstract (Mouse and Keyboard) and direct (Natural Human Interfaces) manipulation and why they relate to each other the way they do.
This is also why I believe the iPad is going to be so revolutionary. My grandparents and aunt who never got the hang of abstract manipulation won’t need to because their interaction with the device will be direct (natural).
I’ve often heard