Actuating force

The force that must be applied to an actuator to complete the intended operation. The computer keyboard provides an example of an everyday object where actuation force matters to the user.

A keyboard’s Activation Point (or Operating Position) is the key travel distance point at which the key is recognized by the keyboard. Actuation force is the force required at this point. In other words, it is the total amount of input force a user must exert to cause any given key to activate consistently. While the amount of force actually needed to press a key down is probably somewhat less important than either ghosting or noise, over time it can have quite a significant impact on usability. Keys that are too easy to press can be sensitive to accidental triggering, while keys that are too stiff can be particularly exhausting after long typing sessions.

Tom’s Hardware blog describes a method for testing keyboard key actuating force: Place each keyboard on a completely flat surface and then adjust it so that the tops of the test keys are perfectly level. Then add standard metric weights to each key until it activates. Tom’s Hardware performed this test on five randomly-selected standard keys (but not the space bar) as part of a comparative review of different keyboards available on the market at the time of the test.