Fewest inputs

What it means

An input is anything the person types, picks or deletes. A value that can be calculated, looked up, prefilled or generated arrives filled, and the person checks it. The person types only what no system knows.

The test

List every field the person can edit. For each one, write why it cannot be computed, looked up, prefilled or generated. A field without a reason is a break. Then count keystrokes on the fields that remain, since a field that needs a delete before the new value costs one input too many. Inputs are counted as the measuring page sets out, and a create form passes when it requires at most one typed field: the Core duplicate key, the email for a person and the domain for an organization.

Levers by surface

Surface	What counts as an input here
Screen	An editable field, a keystroke, a pick, a delete. Formulas, lookups, rollups, automations and prefills supply values, shown read only beside the input they explain. An embedded list on the parent’s detail prefills the link. A click in a number box selects its value so one click and one input replace it. Switching an item to an alternative keeps the original.
Email	Anything the person must write in a reply. A button replaces the reply.
Form	A field the person fills. Fields known from the place the form was opened arrive prefilled.
Document	A value the reader must copy from one place to another.

Research

The reviewer’s third rule reads: “As few inputs (customer should ONLY type, if there is no way, we can calculate, feed, or AI generate what he should input for him) (in the age of AI, humans on;y validate, AI does the work)”. A finding on an ordering system sets the keystroke standard: “If I click inside of the number box, it should automatically select all (allowing me to: click ONE time, type the new total one time (1 click 1 input)”. Another asks that switching an item to an alternative “should keep the original item”.

No published guide or product backs this principle yet; it rests on the reviewer’s feedback alone.