BOZ is an automated graphic design and presentation tool that designs graphics based on an analysis of the task for which a graphic is intended to support. When designing a graphic, BOZ aims to optimize two ways in which graphics help expedite human performance of information-processing tasks: (1) allowing users to substitute simple perceptual inferences in place of more demanding logical inferences, and (2) streamlining users' search for needed information. BOZ analyzes a logical description of a task to be performed by a human user and designs a provably equivalent perceptual task by substituting perceptual inferences in place of logical inferences in the task description. BOZ then designs and renders an accompanying graphic that encodes and structures data such that performance of each perceptual inference is supported and visual search is minimized. BOZ produces a graphic along with a perceptual procedure describing how to use the graphic to complete the task. A key feature of BOZ's approach is that it is able to design different presentations of the same information customized to the requirements of different tasks. BOZ is used to design graphic presentations of airline schedule information to support five different airline reservation tasks. Reaction time studies done with real users for one task and graphic show that the BOZ-designed graphic significantly reduces users' performance time to the task. Regression analyses link the observed efficiency savings to BOZ's two key design principles: perceptual inference substitutions and pruning of visual search.