Frames Representation Lexical Frames Slots Values Structural Frame

Frames

Representation • Lexical: – Frames – Slots – Values • Structural – Frame are collections of Slots • Semantics – Represent classes and objects and inhereitance

Frames • Slots and fillers • Can Describe Instances or Classes • Support Inheritance – IS_A – AKO (A Kind Of)

Procedural Attachment • • • When Constructed When Requested – compute dynamically When Read - constraints When Written - constraints With Respect To – perspectives and contexts

Winston’s Dwarf Example AKO dwarf Is-a Eccentrics Teachers Programmers Professor Crazy Hackers Athletes Endomorphs Weightlifters Shotputters Jacque

Thematic Roles Linguistic Applications • Verbs are actions • Noun phrases – Objects – Participate in action – Roles

Roles • • Agents - cause actions Coagent - partners in causing action Beneficiary Thematic Object Instrument Source and Destination Old and New Surroundings

Roles (cont. ) • • • Conveyance Trajectory Location Time Duration

Representation • Frames – Slots for roles – Verb defines action and defines the frame • Useful for question answering

Example Jane made a cake for Bob. Verb : Make Agent : Jane Beneficiary: Bob Thematic Object: Cake Who made it? What was made? Etc.

Constraints • Verbs have strong preferences for roles • Prepositions limit noun pharses roles – by - agents, conveyance, location – with - coagent, instrument – for - beneficiary, duration – from, to - source, destination • Noun may limit roles • Usually one NP per role