keyboards , keypads and other data entry devices can suffer from a keying ambiguity problem . in a small keyboard , for example , a user &# 39 ; s finger is likely to overlap from a desired key to onto adjacent ones . an iterative method of removing keying ambiguity from a keyboard comprising an array of capacitive keys involves measuring a signal strength associated with each key in the array , comparing the measured signal strengths to find a maximum , determining that the key having the maximum signal strength is the unique user - selected key , and maintaining that selection until either the initially selected key &# 39 ; s signal strength drops below some threshold level or a second key &# 39 ; s signal strength exceeds the first key &# 39 ; s signal strength .