Notifying online conference participant of presenting previously identified portion of content

In a method for notifying a participant of an online conference of when a portion of content will be presented during the online conference, a computer receives at least one data item identifying the portion of content. The computer determines an estimate of a time at which the portion of content will be presented and the level of confidence in the accuracy of the estimate. The computer transmits a user notification including the estimate of the time at which the portion of content will be presented and the level of confidence in the accuracy of the estimate.