  Through a combination of experimental and simulation results, we illustrate
that passive recommendations encoded in typical computer user-interfaces (UIs)
can subdue users' natural proclivity to access diverse information sources.
Inspired by traditional demonstrations of a part-set cueing effect in the
cognitive science literature, we performed an online experiment manipulating
the operation of the 'New Tab' page for consenting volunteers over a two month
period. Examination of their browsing behavior reveals that typical frequency
and recency-based methods for displaying websites in these displays subdues
users' propensity to access infrequently visited pages compared to a situation
wherein no web page icons are displayed on the new tab page. Using a carefully
designed simulation study, representing user behavior as a random walk on a
graph, we inferred quantitative predictions about the extent to which discovery
of new sources of information may be hampered by personalized 'New Tab'
recommendations in typical computer UIs. We show that our results are
significant at the individual level and explain the potential consequences of
the observed suppression in web-exploration.
