  Cataloguing specific URLs, posts, and applications with digital traces is the
new best practice for measuring media use and content consumption. Despite the
apparent accuracy that comes with greater granularity, however, digital traces
may introduce additional ambiguity and new errors into the measurement of media
use. In this note, we identify three new measurement challenges when using
Digital Trace Data that were recently uncovered using a new measurement
framework - Screenomics - that records media use at the granularity of
individual screenshots obtained every few seconds as people interact with
mobile devices. We label the considerations as follows: (1) entangling - the
common measurement error introduced by proxying exposure to content by exposure
to format; (2) flattening - aggregating unique segments of media interaction
without incorporating temporal information, most commonly intraindividually and
(3) bundling - summation of the durations of segments of media interaction,
indiscriminate with respect to variations across media segments.
