As we endeavor to make great recommendations to our viewers, we want to stay aware of the power and potential for algorithms to have unintended consequences. In that spirit, we’ll maintain this page as a document of the various pieces of what we’re building and how it works. Not a technical documentation, but conceptual.

On Nebula’s Featured page we have rows of videos or channels which we call rails. Most of these are human-curated by the editorial team. Some, like the Originals, Plus, and First rails, are automatically populated. For anything populated algorithmically, we’ll note and document here.

Current Rails

Discover Something New

• Position: Second on Featured
• Logic: Random unwatched videos from channels you are not Following
• Refresh Rate: 20min

Channels You Might Have Missed

• Position: Second to last on Featured
• Logic: Random unfollowed channels that do not have recorded video progress
• Refresh Rate: 20min

Up Next

How we recommend what to watch next once a video has finished playing.

• Locations: Up Next section within video detail page and end card shown in video player after a video is completed.
• Section Logic: Next three unwatched videos from current channel then previous three unwatched videos from current channel. If criteria is not met video(s) are not provided.
• End Card Logic: First available video from Up Next section.

Upcoming

Watch Next

• Random selection from a pool of “up next” recommendations from recently watched videos.

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