Binary Selection

An interaction method where users make choices between two options at each step, progressively narrowing down to their desired selection through a series of binary decisions. Binary selection is used in some AAC systems, including Look to Speak where users look left or right to choose between two groups of items. While binary selection reduces the motor demands of each individual choice, it can increase cognitive load and selection time — choosing from 16 items requires up to 4 binary steps. The design must balance minimizing motor demands (fewer distinct movements) against minimizing cognitive demands (fewer sequential decisions).