From the simple to the complex

Chris Harrison, Assistant Professor in Human-Computer Interaction Institute (HCII), Carnegie Mellon University, and Gierad Laput, HCII PhD student, found that studying the various hand activities brought them to broadly segregating them into three types of movements:

ATOMIC HAND ACTIVITIES

These are hand movements that cannot be broken down into distinct stages. For example, wiping, scratching.

Examples of every day atomic hand movements:

COMPOUND HAND ACTIVITIES

These are atomic hand activities that have multiple stages of movements to achieve a single purpose, such as eating and cooking. For example, cooking,

AMBIGUOUS HAND ACTIVITIES:

These hand activities could involve diverse approaches. For example, when the hands open a bottle, they can either twist the cap off or use a bottle opener, which involve different Hands still/Idle. Scrolling on trackpad/phone. Typing on keyboard. Swaying (while locomoting). Typing on phone. Moving/clicking

in which the hands engage in a combination of many atomic hand movements such as chopping or peeling vegetables. Examples of everyday compound hand movements:

Sign language.

movements, though towards the same goal.

Examples of everyday ambiguous hand movements:

■ Shaving. Counting notes. Adjusting watch. Putting on jacket. Putting on lotion. Stretching. mouse. Playing piano.

Washing dishes. Putting on clothes. Showering. Dancing. Cleaning. Putting away clothes. Doing make-up. Kickboxing. Searching pocket. Opening door. Closing door. Reaching for an object.