Because language generation is a purposeful activity motivated by internal goals, it is difficult to draw a boundary between goal-directed thinking and the ensuing production of linguistic output. Often the process is divided into content planning, microplanning, surface realization, and physical presentation. While the last three of these stages can be thought of as operating (in the order stated) on relatively small chunks of information (e.g., resulting in one or two sentences or other utterance types), content planning  is often regarded as a continual process of goal-directed communicative planning, which successively hands over small clusters of ideas to the remaining stages for actual generation when appropriate. We discuss the latter transduction first, in order to highlight its relationship to understanding.