We set up an experimental study using randomly
assigned conditions in real settings. The group of
users were first year Bachelor engineering students
following the Communication A course at our university.
They were instructed to download and use SpeakUp
during five lectures which lasted one hour and a half
each. Upon opening the SpeakUp application the first
time, the app automatically and randomly assigned one
of the following three conditions: thumb, arrow, and
plus one (+1). Thereafter, corresponding icons were
displayed whenever the user opened the application as
demonstrated on Figure 2. All other parts of the
SpeakUp user interface were exactly the same across
the three conditions.