User:KHammerstein (WMF)/sandbox/Highlights

Brief Description
Allow users to highlight sections of text in a page. Most highlighted sections will be surfaced on that page.

Problem it solves
Personal highlights: Long articles often have great information but it can be difficult to navigate through. If users could highlight text they find interesting, they will be able to easily return to those sections. I would also find this helpful to mark sections of an article that I want to come back and edit.

Public highlights: These highlights could benefit other users who are also navigating through long articles. We can display the “popular highlights” of articles, so that even users who don’t highlight themselves can view interesting sections.

Challenges
Showing “popular highlights” would require that multiple users highlight the same thing. That may not happen often enough with free-form text selection. Possible solution: provide a way to quickly select entire sentence or paragraph.

Once an article is edited, the highlight might become invalid. Possible solution 1: Update the highlight to reflect changes. Possible solution 2: Do not update the highlight to reflect changes. If the text does change, change color to gray / or otherwise differentiate. (This might encourage vandalism - a vandal could add content and then highlight it to further surface the vandalism.)