More and more people interact with their mobile phone while
walking. The presented research analyzes; firstly, the negative
effect of walking when considering reading and target selection
tasks, such as weaker performance and higher workload. Here, we
focused on one-handed interaction with a touch screen whereby
the thumb is used as the input device. Secondly, we analyze how
these negative effects can be compensated by increasing the text
size and the size of the targets to select on the mobile phone. A
comparative user study was conducted with 16 participants who
performed target acquisition and reading tasks while standing and
walking. The results show that whilst performance decreases,
cognitive load increases significantly when reading and selecting
targets when walking. Furthermore, the results show that the
negative effect regarding target selection can be compensated by
increasing the target size, but the text reading task did not yield
better performance results for a larger text size due to the
increased demand for scrolling. These results can be used to
inform future designs of mobile user interfaces which might
provide a dedicated walking mode