Transcript Document
Distributed Cognition How a Cockpit Remembers Its Speeds Edwin Hutchins Classical Cognitive Science Thinking about thinking Mental processes Individual human agent How information is represented Transformed Combined Propagated Nature of knowledge Distributed Cognition Unit of analysis Processes within system Representations External Internal Cognitive Systems Organizations Role of material media Physical processes Human actors Material media Interactions Explicit nature of environment Context: MD-80 Cockpit Representations inside cockpit system External to pilots Procedure = behavioral properties Constraint-based Workers-finish-design Task: Memory Task Remembrance of speeds For subsequent use For proper & safe Initial descent Approach to land Instrument landing Artifacts: Wing Shape Artifacts: Speed Card & Fuel Artifacts: ASI & Speed Bugs Actors: Pilot Roles Two pilots/stations Complete dual-flight instrumentations Pilot Flying (PF) Pilot Not Flying (PNF) Process Description Prepare landing data (20 - 30 min. out) Determine gross weight (Fuel Qty) Find correct speed card (2000 lb. incr) Post speed card Set speed bugs on both ASIs Descent - slow plane & configure wings Final approach to land - Vref [Cross-checks & verbal communication] Cognitive Description-External How are speeds represented? How are representations Transformed, Processed, Coordinated? How does the system’s memory work? Observable Representations Gross-weight display (Fuel Qty) Speed card booklet ASIs & speed bugs Speed-select of Flight Director Verbal exchanges between pilots Setting bugs Cross-checks Call-outs /progress reports Additional Representations Memory of each pilot Individual considered as part of system Media in the cockpit Task environment forms memory Internal representations Speed Card & Gross Weight Long-term memory Gross weight Appropriate speeds Functionally durable Filtered information Correct weight = correct speeds Distributed access Social space Knowledge Distribution & Transformation Transformations of representations Verbal (as relayed between PNF & PF) Via speed bug settings Cross-checking & redundancy Time-critical procedure indications Configuration Changes Speed determined ATC instruction Position in approach ASI needle nears appropriate bug PF calls for flap/slat configuration PNF configures flaps/slats Verification & cross-checks (with speed card) Salmon Speed Bug Final approach speed reference (Vref) Spatial relation with ASI needle PF to track speed PNF to determine deviations Verbal representation of call-outs Lightens demand on visual load of PF External Representations Summary Speed bugs Resource for later processes Durable working memory Coordinated representations Verbal Speed card/fuel qty Configurations “System memory” Cognitive Description-Internal Cognitive tasks of pilots Task specification Not procedural recount Provide constraints on useable Representations Processes Interpretation not recall Function in system memory Speed Card & Gross Weight Pattern matching Implicit learning Internal structure for prediction Interpret values Card design Working memory Setting bugs - varied sequences Configuration Change Bugs Numerical relations Spatial position Space of speeds “Configuration zones” Superimposing representations Functional systems Configuration Zones Salmon Speed Bug Numerical relation Scale of ASI and need positioning Spatial proximity Scale-reading task Base of salmon bug Verbal call-out - aural cue Notion of Memory Traditionally a psychological function A series of tasks in a functional system Recognition & recall Pattern matching Cross-modal transformations Distributed Among human agents Between human agents Transformed external representations Workers Finish the Design Provides constraints and artifacts Salmon bug Engineer’s design Ease of location Ease of interpolation Pilot’s use Determine 5-kt. deviations Not anticipated by designer (engineer) Cockpit as Cognitive System Unit of analysis Transforms & propagates information Use of representations Notion of memory task Redundant & robust