“…There is, however, an additional aspect of using smartphone as compared to desktop computer: namely, the touchscreen of the smartphone can also easily be operated with thumbs instead of index fingers; which allows more mobility for the user, and which is in fact the more common and natural way for smartphone usage in general (e.g., Azenkot & Zhai, 2012;Bröhl, Mertens, & Ziefle, 2017). Several studies have shown that using index finger responses instead of thumbs can lead to different results: In particular, it has been consistently found that more accurate general input (mainly: typing) can be given using index fingers (Buschek, De Luca, & Alt, 2016;Lehmann & Kipp, 2018;Wang & Ren, 2009;Wobbrock, Myers, & Aung, 2008). However, results have been mixed regarding speed differences, which seems to depend on the particular input type and study design (Azenkot & Zhai, 2012;Goel, Jansen, Mandel, Patel, & Wobbrock, 2013;Lehmann & Kipp, 2018;Wobbrock et al, 2008).…”