Status Confirmation Principles Should be possible to determine product is powered on or off by touch. Operations should produce a clear response, such as a click, or tone,etc. Toggle control reference points should be clear producing a click, or tone. Knobs should have an indication line so that the setting position can be determined by touch. Aural Response Principles Consistent aural cues should be produced in response to operations.
Feedback is desirable when the batteries are low, or an operation is complete.
On domestic appliances, indications should be in plain English. When symbols are used, generally recognizable symbols should be selected. Letters or engraved indications should be at least 3.4 mm in height. Safety Principles Switches should not be too easily operated by touch. Take adequate precautions against buttons that could cause problems if pressed by mistake.