The present disclosure provides systems and methods for estimating audience member engagement with content, or distinguishing between users consuming content and users who have become distracted or have left. User presence or attention may be estimated from user interactions with or skipping of content, with the user interactions either compared to high quality engagement data from small audience measurement panels, or extrapolated based on a temporal-engagement curve. An attention gap may be estimated, representing users that were not present for or not engaged with or paying attention to a presentation of content at a client device. This allows the measurement system to distinguish between users who consumed and potentially enjoyed the content, and users who did not, even as client devices of both sets of users receive and present the content items.