. e.g., Function of elopement is a lost child In these cases, function-based definition by proxy . More restrictive definition that keeps behavior within control of analyst Reasons to Use Topography-based Definitions Behavior analyst does not have direct, reliable, or easy access to functional outco Cannot rely on function of behavior because each occurrence does not produce relevant outcome Other Uses - When the relevant outcome is sometimes produced by undesirable variations of t response class . e.g., A basketball player scores with a sloppy shot from the free throw line Definition should encompass produce relevant outcomes Writing Target Behavior Definitions A Inclusions Exclusions Characteristics of Good Definitions - Objective . Refer only to the Clear . Readable and Complete . Delineate of definition