Universität Zürich

IKMZ - Department of Communication and Media Research

Media Change & Innovation Division

Andreasstrasse 15
CH-8050 Zurich
Phone +41 (0)44 635 20 92
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How Long and What For? Tracking a Nationally Representative Sample to Quantify Internet Use


Noemi Festic /

Moritz Büchi /

Michael Latzer

Working Paper. University of Zurich, Zurich.

Testing communication theories (e.g., on digital media use and effects) requires a valid empirical basis, yet especially for use time measures, retrospective self-reports may be biased. This study draws on a unique data set of 923 Swiss internet users who had their internet use tracked for at least 30 days on mobile and desktop devices (13.2 million time-stamped events) and took part in a survey covering person-level background variables. The analysis focuses on active use time overall and on the major services Google Search, YouTube, WhatsApp, Instagram, Facebook, and the online newspaper 20 Minuten. The results showed that the time people actually spend online was overestimated in self-reports. Regarding user shares for the major services, there were meaningful differences between age groups. These differences were less pronounced when it came to the time spent using these services. Internet users in all social groups spent the majority of their time online on a mobile device. Over the course of a day, the major services varied in their frequency of use: for example, messaging peaked before noon and in the late afternoon, whereas online news use was comparably constant at a lower level.