How long is a 'long' key press?

摘要

This paper provides the results of experiment in which we measured duration of key press on a mobile phone. 44 subjects pressed keys without visual or audio feedback. We tested two kinds of keys to examine the effect of key position, and found no significant difference between key press duration of those keys. Assumed error analysis shows that subjects tend to press shorter than the threshold they learned in practice session. It has implications for design that if the key is positioned in a place where users cannot easily see, it will be better to set the required duration for a long press shorter than the other keys. This will result in a more error-proof product.