Cognitive Models Agenda Who Am I? Cognitive Models Situated Action Activity Theory Distributed Cognition How to use these models Compare to Engineering Models CS 6750 Fall 2001

Who Am I? Elizabeth Mynatt Associate Professor, CoC, HCI Everyday Computing Lab mynatt@cc.gatech.edu CS 6750 Fall 2001

Models of Human Cognition Human as “information processing system” Predict performance, not describe truth Other models? Distributed cognition Activity theory Situated action CS 6750 Fall 2001

Situated Action Emergent property of moment-by-moment interactions Relation between persons and arenas Improvisation Detailed temporal accounts De-emphasizes rigid plans and rational problem solving CS 6750 Fall 2001

Activity Theory Subject, object, actions and operations Flexible in face of changing conditions Mediation by artifacts Transformative relationship CS 6750 Fall 2001

Distributed Cognition Distributed collection of interacting people and artifacts Less emphasis on individual cognition; system goal Representations and transformations Collaboration CS 6750 Fall 2001

Comparing Models Goals versus “retrospective reconstructions” Persistent structures People and things Level of detail CS 6750 Fall 2001

Square 1 What do you know? Where not to start: Marketing data Detailed surveys Jumping into design Asking the customer … CS 6750 Fall 2001

Knowing your user Understand underlying structure / goals / values … Make tacit knowledge explicit Train your intuition Enable tech transfer Apprentice model CS 6750 Fall 2001

Observation You just landed on planet X Teach someone to drive in a conf room People use knowledge in the world Lots of non-verbal details Listen to the language Videotaping CS 6750 Fall 2001

Interviews Observation grounds interviews Keeping the interview open Cheat sheets Avoid summaries, abstractions Create interpretations together “What should I have asked?” Tape recording CS 6750 Fall 2001

Other techniques Exercises Focus groups Surveys Sorting, ordering Reaction to prototypes Surveys Detailed data, evaluation CS 6750 Fall 2001

Triangulation Multiple viewpoints Different types of data Discover bias Better data Shared understanding CS 6750 Fall 2001

Model Human Processor Perceptual, cognitive and motor processors Recognize-act cycle Engineering models GOMS KLM GOMS CCT CS 6750 Fall 2001