Issuing commands to tomorrow's computers, tablets and smartphones could be as simple as tapping out a few beats on a touchscreen or trackpad, French researchers suggest.

Researchers at the University of Paris-Sud have investigated the feasibility of issuing commands to computers and electronic devices by tapping beats on the devices themselves, a practice they called rhythmic interaction.

Little academic work has been done on the feasibility of using rhythmic patterns as a form of user input. But rhythmic interaction could provide handy shortcuts for issuing commands to touch-sensitive computational devices, said Emilien Ghomi, who summarized the researchers' work at the Association for Computing Machinery's Conference on Human Factors in Computing Systems (aka CHI 2012) in Austin, Texas.

Tapping on a device may be a particularly effective way to issue commands to devices that have limited user interfaces, such as smartphones or music players, Ghomi argued. While they would not be ideal as the primary interface, they could be handy as shortcuts, much like computer hot-key combinations are used today.

While on a smartphone, a user could tap out a command on the back of the handset while continuing to talk. A few taps on a music player with a very small touchscreen, such as an Apple iPod Nano, could trigger commands that would otherwise require a tedious digging through successive layers of menus, Ghomi noted. Building in the capability to recognize taps would be a trivial task for any OS maker, and a program to intercept taps would take up minimal device memory, he said.

The researchers conducted two sets of experiments involving 14 people, using laptops that would accept a series of finger taps on a trackpad as a form of input. The researchers created 30 rhythmic patterns, or motifs, out of a possible 799 patterns that could be generated with six beats or less.

Each motif is a different combination of three different types of taps. In a long tap, the user keeps the finger on the trackpad for two beats. A short tap consists of a single beat, and a pulse tap is a quick tap on the touchpad. The researchers assume that each combination of taps would be carried out across a regular interval at about 120 BPM (beats per minute) though the speed of the interval could be easily changed to match the user's dexterity.

In their tests, the researchers had found that users could easily learn and reproduce this series of taps, and could then use these taps as shortcuts for commands. After the tests were completed, 9 of the 14 participants preferred using the rhythmic patterns over the hot keys, and another two had no preference.

The research could open a new form of user interface, noted Princeton University computer science assistant professor Rebecca Fiebrink, who moderated Ghomi's talk. People all over the world can naturally recognize and respond to rhythms. "Rhythm is something people have an innate ability to perform" yet it's not used as an input very often, she said, adding that someone does not need to be trained as a musician to easily learn the researchers' rhythmic motifs.

Ghomi did not estimate how many tap patterns a user could potential memorize, though he speculated that it would probably not be that much different than the total number of hot-key combinations users remember. He referred to earlier studies showing fluent computer users memorize about eight hot-key combinations.