I recently read an article on a design pattern called "inline modals" here: http://uxmovement.com/content/inline-modal-windows-display-new-content-in-page-sections/. I think it's a good pattern that elegantly solves the context-killing and disruption issues that traditional modals have.
I was wondering if there is any usability research on these or if anyone has observed the usability of them first hand and could share their findings? If you had any other examples of inline modals in the wild I would appreciate that as well.
One tangental thought I had with inline modals in Apple's implementation below is that I wonder if we confuse users with small icon buttons (especially plus/minus icons) that always seem to do different things. In one application they could add/remove items, in another it slides content up/down, here it activates a small, inline modal area.
A live example of an inline modal can be found here: http://www.apple.com/osx/how-to-upgrade/. Picture of above URL:
Step 1 is the starting state, the section below it (step 2), is shown with the inline modal activated. Clicking the close button will bring it back to the same state as step 1.