dyadic

Dyadic is an adjective meaning relating to a pair or consisting of two parts. The term comes from the concept of a dyad, a pair or duo, and is used across disciplines to indicate two-part relationships, two-place operations, or products formed from two elements.

In mathematics and related fields, dyadic describes objects built from two components. Dyadic rationals are numbers of the form m/2^n with integers m and n. Dyadic intervals partition the unit interval into halves at each stage, producing a recursive grid of subintervals. In higher dimensions, dyadic cubes are products of dyadic intervals, forming a standard grid used in analysis. The dyadic or outer product of two vectors yields a rank-1 matrix, commonly written as u v^T.

In the social sciences and network analysis, dyadic data capture information about interactions between two units, such as person-to-person relationships or bilateral trade between countries. Analytic methods often focus on the characteristics of both parties and their interaction.

In psychology and psychotherapy, a dyadic approach centers on two individuals as the main unit of analysis or intervention, such as a therapy pair or a couple, emphasizing interdependent processes and communication patterns.

In computing and logic, dyadic (or binary) refers to operations, predicates, or functions that require two operands or arguments, as opposed to unary or monadic forms. The term remains a general descriptor rather than a single specific theory or technique.