When I see a question in the "all questions" list on page one, can I assume it is a new question, or an old one with a new answer, or do the questions shuffle automatically?
On the front page, questions are sorted by those most recently active. This includes:
- The question was posted
- An answer was posted
- The question (including tags) was edited
- An answer was edited
- A bounty was added
- The question was closed or reopened
And maybe one or two other actions. So questions are sorted by which ones had these actions done more recently.