Comp 15 - Usability and Human Factors Unit 3b - Cognition and Human Performance This material was developed by Columbia University, funded by the Department of Health and Human Services, Office of the National Coordinator for Health Information Technology under Award Number 1U24OC000003.

Memory Short term sensory storage Working Memory Long Term Memory Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Memory Processes Encoding: process of putting things into memory Storage: how information is maintained in memory Retrieval: accessing information from memory Encoding: process of putting things into memory Storage: how information is maintained in memory Retrieval: accessing information from memory Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Health IT Workforce Curriculum Version 2.0/Spring 2011 Working memory (WM) WM is the short-term memory or temporary store that keeps information “active” When processing in WM, we bring information from the sensory register and long-term memory (LTM) into WM Information is encoded WM has limitations The limitations of WM have major implications for system design Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

WM Capacity Constraints The upper limit of capacity is 7 +/- 2 chunks of information A “chunk” is the unit of WM space, defined jointly by the physical and cognitive properties that bind items within the chunk together The upper limit of capacity is 7 +/- 2 chunks of information A “chunk” is the unit of WM space, defined jointly by the physical and cognitive properties that bind items within the chunk together Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Long-term memory (LTM) LTM provides a mechanism for storing information and retrieving it at a later time Relatively permanent storage system Highly organized knowledge structures Different types of information LTM provides a mechanism for storing information and retrieving it at a later time Relatively permanent storage system Highly organized knowledge structures Different types of information Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Health IT Workforce Curriculum Version 2.0/Spring 2011 Carving Up Knowledge Factual Knowledge Risk factors for coronary artery disease Declarative or Conceptual Knowledge Deeper level of understanding Part of a network of knowledge and beliefs Procedural Knowledge How to perform various actions Decision rules in guidelines Collaborative Knowledge (people and artifacts) Individual and collective Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Cognitive Constructs for Mental Representation Schema Mental Images Representation of perceiving some object, event, or scene Propositions Capture the meaning of linguistic and other symbolic forms Mental models Schema Representation of perceiving some object, event, or scene Mental Images Capture the meaning of linguistic and other symbolic forms Propositions Mental models Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Schemata Represent a higher level kind of knowledge structure Representing the generic concepts stored in memory (e.g., fruits, chairs, geometric shapes, and vertebrates) Schemata for concepts underlying situations, events, sequences of actions and so forth Models of the external world Represent a higher level kind of knowledge structure Representing the generic concepts stored in memory (e.g., fruits, chairs, geometric shapes, and vertebrates) Schemata for concepts underlying situations, events, sequences of actions and so forth Models of the external world Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Schemata (cont.) To process information with the use of a schema is to determine which model best fits the incoming information Features of schemata Constants (all birds have wings) Variables (chairs can have between 1 and 4 legs) Active recognition devices aimed at evaluating how well they fit to the data being processed Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Health IT Workforce Curriculum Version 2.0/Spring 2011 Bird Schema Type: animal Locomotion: flies* (default value) walks swims Communication: sings* squawks Size: small* medium large Habitat: trees* lands waters Food: insects* seeds fish Colors: Variable Image of 2 types of birds. Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011

Scripts Eating in a Restaurant, Attending a Lecture, The Visit to the Dentist’s Office Knowledge structure captures general information about routine events Customers, waiter, cook Professor, GSIs, students Dentist, assistant, patient, and the drill Scripts have typical roles Customers are hungry Students are thirsty for knowledge Patient needs 6 cavities filled, some root canal work and a bridge installed Scripts have entry conditions We can fill in or infer the scenes and actions that are not explicitly mentioned Scripts elicit elaborated knowledge of an event type Component 15/Unit 3b Health IT Workforce Curriculum Version 2.0/Spring 2011