| 主权项 |
1. A method performed by data processing apparatus, the method comprising:
receiving a request for content to be presented in a content slot that defines a location on a content page; calculating an active view scroll distance of the content slot relative to the content page based on the location of the content slot on the content page, the active view scroll distance corresponding to a distance that the content page would have to be scrolled to reduce visibility of the content displayed in the content slot by a specified amount, the specified amount at least 20%; identifying a plurality of candidate content items to provide for display within the content slot; identifying, for each candidate content item of the plurality of candidate content items, prior performance data identifying, i) for each impression of the candidate content item, a respective active view scroll distance of a respective content slot in which the candidate content item was displayed relative to a respective content page including the respective content slot and ii) a performance metric of the candidate content item for different active view scroll distances identified by the prior performance data; determining, for each candidate content item, from the different active view scroll distances, an active view scroll distance closest to the calculated active view scroll distance; determining, for each candidate content item, the performance metric of the candidate content item corresponding to the active view scroll distance closest to the calculated active view scroll distance; identifying, from the plurality of candidate content items, one or more candidate content items having performance metrics that satisfy a threshold performance value corresponding to the calculated active view scroll distance; selecting, from the one or more candidate content items, a content item for display in the content slot; and providing, for presentation, the selected content item in response to the request. |
