transduction

Transduction is the deliberate conversion of a signal, datum, or energy form into another type while preserving its informational content. The operator takes inputs in one representational or physical modality and produces outputs in a different modality, mapping input states to output states via a defined transfer function. Parameters: (1) input modality must differ from output modality, (2) a transfer function must exist that maps input states to output states, (3) the process must be intentional—natural passive conversion without an operator does not qualify. Examples include analog-to-digital converters (physical→discrete), linguistic derivation by class change (noun→verb without affix), and sensory encoding (physical stimulus→neural signal). The concept is human-made because it names a constructed practice of purposeful cross-modal conversion, formalized in engineering, linguistics, and computing. [formal: transductio | substrate: behavior | horizon: hours | explicit: yes | epoch: 0.01]