Usability implications of partial page scrolling

Question

What are there the usability implications for a long list of items (f.e. facebook news stream) to use an internal scrolling (just the list panel) vs a full page scrolling.

Edit1: Do you have references of analysis/guidelines discussing this issue?

Answer 1

Depends on the composition of the page.

If the page displays other information and it is desired to keep an eye on it while scrolling that long list, then it may be preferable to use what you call "internal scrolling".

On the other hand, such scrollable parts are generally considered to be signs of a bad UI design. If you bring the argument that without scrolls the page would become huge, then you may want to reconsider the page layout and what information is really needed here together. Splitting a page into multiple specific views without scrolls might be a better idea.

Answer 2

From my experience multiple scrollbars on a page frustrate users, The best thing you can do is use CSS/javascript/jQuery to make items that you want to stay on the page move with the user. Slashdot's commenting system uses something similar to keep information pinned to the top of the page where it's needed. There's lots of other examples on the web, and it generally leaves a good impresssion on the user.