  Traditionally, the efficiency and effectiveness of search systems have both
been of great interest to the information retrieval community. However, an
in-depth analysis of the interaction between the response latency and users'
subjective search experience in the mobile setting has been missing so far. To
address this gap, we conduct a controlled study that aims to reveal how
response latency affects mobile web search. Our preliminary results indicate
that mobile web search users are four times more tolerant to response latency
reported for desktop web search users. However, when exceeding a certain
threshold of 7-10 sec, the delays have a sizeable impact and users report
feeling significantly more tensed, tired, terrible, frustrated and sluggish,
all which contribute to a worse subjective user experience.
