Meaning-Based Knowledge Representations

John B. Black

Teachers College

Columbia University

Propositions as Units ofDeclarative Knowledge

and MemoryProposition = Relations + Entities

The clerk sold the customer the book proposition notation:

sold(clerk, book, customer)

The book was good.proposition notation:

good(book)

The boy went home.proposition notation:

• Went(boy, home)

Multi-Proposition Sentence

The old Professor gave a boring lecture

gave(Professor,Lecture,students)

note: students an inference

old(Professor)

boring(lecture

Episodic and Semantic Memory

• Episodic Memory is Memory for Episodes in your life – what we have been talking about

• Word list experiment is example• Also naturally ocuring events (e.g., 9/11)

• Semantic Memory is Memory for Your

Knowledge about the World• Lexical Knowledge about Words• Object Schemas (e.g., room schema)• Event Schemas (e.g., scripts)

Memory for Scripts

• Scripts are schemas that contain actions, roles for actors, and props that occur in situations by convention

• If ask group of people what happens in one of these situations there is a lot of agreement (doesn’t have to be exact)

• When people read or see some of the pieces of a script they activate the rest and it all goes into an episodic memory for event

Example Empirical Script• VISITING A DOCTOR • Enter office • CHECK IN WITH RECEPTIONIST SIT DOWN • Wait • Look at other people • READ MAGAZINE • Name called • Follow nurse • Enter exam room • Undress • Sit on table • Talk to nurse • NURSE TESTS • Wait • Doctor enters • Doctor greets • Talk to doctor about problem • Doctor asks questions • DOCTOR EXAMINES • Get dressed • Get medicine • Make another appointment • LEAVE OFFICE

Example Story from Study

The Doctor

John was feeling bad today so he decided to go see the family doctor. He checked in with the doctor’s receptionist, and then looked through several medical magazines that were on the table by his chair. Finally the nurse came and asked him to take off his clothes. The doctor was very nice to him. He eventually prescribed some pills for John. Then John left the doctor’s oftice and headed home.

Experimental Results

• In both recall and recognition, people misremembered missing script items as having been in text – almost at same level as actually stated items

• Reading time pauses when there is a script gap

• Story statements that blocked script actions were remembered best, and ones that were irrelevant remembered least

Scripts are Good Autobiographical Memory Cues

• Memory Cues (best to worse)• remember when you went to a

restaurant (script activity cue)• remember when you paid for

something (positive action cue)• remember when you didn’t get

what you wanted (negative action cue)• remember when you were

impatient (affect cue)

Script Activity vs Action Cues

• Went to a restaurant (script activity cue)• Got what you wanted (action cue)• cued a memory faster than•• Got what you wanted• Went to a restaurant

• and negative or failure actions were slowest of all:

• Went to a restaurant.• Didn’t get what you wanted.

Encoding Specificity Principle

• Memory are encoded with specific context and knowledge used to process

• Restoring that context aids in memory retrieval

• Here scripts were the context processed with so they are good cues

• When trying to remember something from past, then of what activity (e.g., high school classmate name study)