defining comparison in a computational linguistics framework
Download
Skip this Video
Download Presentation
Defining Comparison in a Computational Linguistics Framework

Loading in 2 Seconds...

play fullscreen
1 / 50

Defining Comparison in a Computational Linguistics Framework - PowerPoint PPT Presentation


  • 520 Views
  • Uploaded on

Defining Comparison in a Computational Linguistics Framework. Maria Milosavljevic Intelligent Interactive Technologies Group, CSIRO Mathematical and Information Sciences North Ryde, NSW http://www.cmis.csiro.au/Maria.Milosavljevic/. Overview. The Basic Ideas Language Technology

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Defining Comparison in a Computational Linguistics Framework' - salena


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
defining comparison in a computational linguistics framework

Defining Comparison in a Computational Linguistics Framework

Maria Milosavljevic Intelligent Interactive Technologies Group,

CSIRO Mathematical and Information Sciences North Ryde, NSW

http://www.cmis.csiro.au/Maria.Milosavljevic/

overview
Overview
  • The Basic Ideas
  • Language Technology
  • Some Definitions
  • An Ontology of Comparisons
  • Comparison in Context
  • Conclusions and Future Directions
the basic idea
The Basic Idea
  • Learning is incremental…

we augment existing knowledge with new knowledge in order to maximise the extent to which the new knowledge coheres with our existing knowledge

the user s knowledge
The User’s Knowledge
  • Teaching should capitalise on the user’s existing knowledge:
    • maximise the hearer’s conceptual coherence of that entity
    • prevent the hearer from forming misconceptions about that entity
  • Most NLG systems utilise a model of the user’s knowledge to prevent repetition
  • It should also be used to build on her existing understanding
overview5
Overview
  • The Basic Ideas
  • Language Technology
  • Some Definitions
  • An Ontology of Comparisons
  • Comparison in Context
  • Conclusions and Future Directions
natural language technology

Natural Language Generation

Natural Language Analysis

Text

Text

Natural Language Technology

‘Meaning’

objectives of text generation
Objectives of Text Generation
  • Reduce information overload by constructing appropriate presentations on-demand
  • Tailor text to the individual’s knowledge, needs, abilities, situation, language, previous interactions, etc.
  • Decrease document construction and maintenance costs: texts are updated as underlying knowledge changes
overview8
Overview
  • The Basic Ideas
  • Language Technology
  • Some Definitions
  • An Ontology of Comparisons
  • Comparison in Context
  • Conclusions and Future Directions
some definitions
Some Definitions
  • A propertyp of an entity is an ordered pair <a, v> consisting of an attributea and its corresponding valuev, for example <colour, red>.
  • A focused entity is the topic of a text, or the entity being discussed in a text.
some definitions10
Some Definitions
  • A proposition is a predication of a property to an entity, or the relationship which holds between two entities (for example, <part-of, mouth-piece, clarinet>).
  • A description of a focused entity is defined as the linguistic realisation of a set of one or more propositions, the purpose of which is to allow the hearer to build a mental model of the focused entity.
definition comparative proposition
Definition: Comparative proposition
  • A comparative proposition is a proposition which states the existence of a difference or a similarity between two entities. For example, the comparative proposition below states that there is a difference between the entities dromedary camel and bactrian camel. Note that the attributes match (number-of-humps). This is important in order to draw similarities and differences together.

(difference

(hasprop dromedary-camel (number-of-humps 1)),

(hasprop bactrian-camel (number-of-humps 2)))

definition comparison
Definition: Comparison
  • A comparative clause is the linguistic realisation of a comparative proposition.
  • A comparison is a set of one or more comparative propositions which together express the differences and/or similarities between two entities.
  • A comparative text is the linguistic realisation of a comparison.
  • For convenience sake, we will also use the term comparison to mean comparative text.
  • A comparator entity is the entity which is being compared to the focused entity within a comparative text.
definition uni bi focal
Definition: Uni/Bi-Focal
  • A uni-focal comparison is a comparative text which has one primary focused entity.

“Hearing aids have the same basic components as any public-address system, but all the components are miniature and the amplified sound is delivered to the ear of the hearing-aid user only.”

  • A bi-focal comparison is a comparative text which has two equally-important foci.
bi focal comparison
Bi-focal Comparison

Rabbits and Hares, common name for certain small, furry mammals with long ears and short tails. Although the names rabbit and hare are often used interchangeably, in zoological classification the species called rabbits are characterised by the helplessness of their offspring, which are born naked and with closed eyes, and by their gregarious habit of living in colonies in underground burrows. (The exception is the cottontail of North America, which does not dig burrows; its nest is on the surface, usually in dense vegetation, and it is not social.) Species designated zoologically as hares are born furred and with open eyes, and the adults merely construct a simple nest and rarely live socially. Furthermore, the hare is generally larger than the rabbit and has longer ears with characteristic blackmarkings. Moreover, the skulls of rabbits and hares are distinctly different. ... (Encarta Encyclopedia)

definition multi focal
Definition: Multi-Focal
  • A n-focal comparison is a comparative text which has n equally-important foci. We will use the term multi-focal comparison to refer to a comparison with more than two foci.

“The buffeo, the smallest dolphin, is less than 1.2 m (less than 4 ft) long; the largest, the bottle-nosed dolphin, reaches a length of 3 m (10 ft). The killer whale is considered a dolphin despite its much greater length of 9 m (30 f t).”

overview16
Overview
  • The Basic Ideas
  • Language Technology
  • Some Definitions
  • An Ontology of Comparisons
  • Comparison in Context
  • Conclusions and Future Directions
ontology of comparisons

Whole text

Partial text

Bi-focal

Direct

comparison

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

direct comparison 1
Direct Comparison 1

Rabbits and Hares, common name for certain small, furry mammals with long ears and short tails. Although the names rabbit and hare are often used interchangeably, in zoological classification the species called rabbits are characterised by the helplessness of their offspring, which are born naked and with closed eyes, and by their gregarious habit of living in colonies in underground burrows. (The exception is the cottontail of North America, which does not dig burrows; its nest is on the surface, usually in dense vegetation, and it is not social.) Species designated zoologically as hares are born furred and with open eyes, and the adults merely construct a simple nest and rarely live socially. Furthermore, the hare is generally larger than the rabbit and has longer ears with characteristic blackmarkings. Moreover, the skulls of rabbits and hares are distinctly different. ... (Encarta Encyclopedia)

direct comparison 2
Direct Comparison 2

Microsoft Carpoint Example Comparison between a BMW and an Audi

Choose a model 1998 1998

BMW Audi

3-Series A4

Price Range $21,390 - $41,500 $23,790 - $30,040

Airbags Driver, Passenger, Driver, Passenger,

Side Side

Choose a trim 318i 2.8

Base Price (MSRP) $26,150 $28,390

Base Invoice $22,930 $24,944

Destination Charge $570 $500

Driver Airbag Standard Standard

Passenger Airbag Standard Standard

...

definition direct
Definition: Direct
  • A direct comparison is a bi-focal comparative text which exists as an entire text, and whose purpose is to: (i) highlight that the two foci exist and are highly similar; (ii) describe the foci; and (iii) distinguish the two foci.
ontology of comparisons21

Whole text

Partial text

Bi-focal

Multi-focal

Direct

comparison

Significant

type

comparison

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

Objective: distinguish

significant type comparison
Significant Type Comparison

In colder climates, ground squirrels commonly hibernate; tree squirrels do not.(Encarta Encyclopedia)

The feathers of the male bird may be different in appearance from those of the female bird of the same species. (Encarta Encyclopedia)

definition significant type
Definition: Significant Type
  • The significant types of an entity are the partitionings of that entity into groups or parts of some kind. For example, an animal class can be partitioned into groups such as: male and female; captive and free; and young and adult, or into sub-parts such as head, body and tail, and so on.
  • A significant type comparison is a multi-focal comparative text which is used within a description of a focused entity in order to: (i) inform the reader of the presence of some or all of the significant types of the focused entity; and (ii) provide the most relevant distinction(s) between these significant types.
ontology of comparisons24

Whole text

Partial text

Bi-focal

Multi-focal

Uni-focal

Direct

comparison

Significant

type

comparison

Domain-based

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

Objective: distinguish

Comparator: potential confusor

Objective: 1. misconception prevention

2. express uniqueness

definition domain based
Definition: Domain-based
  • A domain-based comparison is a uni-focal comparative text which occurs within a description of a focused entity, and which draws the hearer\'s attention to another similar entity within the domain in order to: (i) exemplify the uniqueness or non-uniqueness of the focused entity; and (ii) prevent the hearer from forming misconceptions about the similarity or otherwise of the two entities.
ontology of comparisons26

Whole text

Partial text

Bi-focal

Multi-focal

Uni-focal

Direct

comparison

Significant

type

comparison

Domain-based

Set Complement

comparison

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

Objective: distinguish

Comparator: potential confusor

Objective: 1. misconception prevention

2. express uniqueness

set complement comparison
Set Complement Comparison

... the claws are short and lack the sheath that covers retracted claws in other cat species. (Grolier Encyclopedia)

Being a cylindrical pipe stopped at one end, the clarinet overblows to the interval of a 12th above the fundamental pitch (unlike flutes and oboes, which overblow to the octave).(Encarta Encyclopedia)

definition set complement
Definition: Set Complement
  • A contrast set is any form of grouping to which the focused entity belongs, such as its parent class or supertype in a generalisation hierarchy.
  • A set complement comparison is a domain-based comparison, between a focused entity and its complement in a contrast set to which it belongs.
  • NOTE: In order to determine the uniqueness of the focused entity in the contrast set, we need to compare the focused entity to its complement in the contrast set, since the focused entity is not different to itself.
ontology of comparisons29

Whole text

Partial text

Bi-focal

Multi-focal

Uni-focal

Direct

comparison

Significant

type

comparison

Domain-based

Set Complement

comparison

Clarificatory

comparison

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

Objective: distinguish

Comparator: potential confusor

Objective: 1. misconception prevention

2. express uniqueness

clarificatory comparison
Clarificatory Comparison

Track bikes are similar in appearance and construction to road racing bicycles, except that they lack brakes, have no variable gear mechanism, and weigh about 7 to 9 kg (about 15 to 20 lbs). Mountain bikes are built to withstand the rigorous conditions of off-road riding. Although their frames are commonly constructed of the same materials as other racing bikes, they have sturdier tubing. (Encarta Encyclopedia)

Sheep, are hollow-horned ruminants belonging to the genus Ovis, suborder Ruminata, family Bovidae. Similar to goats, sheep differ in their stockier bodies, the presence of scent glands in face and hind feet, and the absence of beards in the males. Domesticated sheep are also more timid and prefer to flock and follow a leader. (Grolier Encyclopedia)

definition clarificatory
Definition: Clarificatory
  • A potential confusor of a focused entity is an entity which is highly similar to the focused entity, and which the hearer might confuse for the focused entity.
  • A clarificatory comparison is a domain-based comparison, between a focused entity and its potential confusor. The purpose of the comparison is to distinguish the focused entity clearly from the potential confusor, thus preventing the hearer from forming misconceptions about the similarity (or otherwise) of the entities.
ontology of comparisons32

Whole text

Partial text

Bi-focal

Multi-focal

Uni-focal

Direct

comparison

Significant

type

comparison

Domain-based

Familiarity-based

Set Complement

comparison

Clarificatory

comparison

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

Objective: distinguish

Comparator: known

Objective: better understanding

Comparator: potential confusor

Objective: 1. misconception prevention

2. express uniqueness

definition familiarity based
Definition: Familiarity-based
  • A familiarity-based comparison is a uni-focal comparative text which occurs within a description of a focused entity which draws the hearer\'s attention to the similarities and/or differences between a focused entity and another entity with which the hearer is familiar, in order to allow the hearer to form a conceptual model of the focused entity more easily.
ontology of comparisons34

Whole text

Partial text

Bi-focal

Multi-focal

Uni-focal

Direct

comparison

Significant

type

comparison

Domain-based

Familiarity-based

Set Complement

comparison

Clarificatory

comparison

Like-entity

comparison

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

Objective: distinguish

Comparator: known

Objective: better understanding

Comparator: potential confusor

Objective: 1. misconception prevention

2. express uniqueness

like entity comparison
Like-entity Comparison

Sheep, are hollow-horned ruminants belonging to the genus Ovis, suborder Ruminata, family Bovidae. Similar to goats, sheep differ in their stockier bodies, the presence of scent glands in face and hind feet, and the absence of beards in the males. Domesticated sheep are also more timid and prefer to flock and follow a leader. (Grolier Encyclopedia)

All spiders are alike in some ways. Spiders have eight legs. Their bodies have two parts. Some people think that spiders are insects. But insects have six legs, and their bodies have three parts. Spiders and insects are two different kinds of animals. (National Geographic Encyclopedia K-2)

definition like entity
Definition: Like-entity
  • A like-entity comparison is a familiarity-based comparison between the focused entity and a highly similar comparator entity.
ontology of comparisons37

Whole text

Partial text

Bi-focal

Multi-focal

Uni-focal

Direct

comparison

Significant

type

comparison

Domain-based

Familiarity-based

Set Complement

comparison

Clarificatory

comparison

Like-entity

comparison

Illustrative

comparison

Ontology of Comparisons

Comparative text

user-initiated

system-initiated

Objective: distinguish

Comparator: known

Objective: better understanding

Comparator: potential confusor

Objective: 1. misconception prevention

2. express uniqueness

illustrative comparison
Illustrative Comparison

Tachyglossus aculeatus, found in many habitats across Australia and Tasmania, is 35 to 53 cm long and has spines like a hedgehog\'s. (Encyclopedia Britannica)

They are about the size of a large cat and have long, bushy tails, a shaggy brown coat, and large ears. (Aye-aye, Encarta Encyclopedia)

Slightly larger than chinchillas, the mountain viscachas have long, rabbitlike ears and a long squirrel-like tail.(Encarta Encyclopedia)

definition illustrative
Definition: Illustrative
  • An illustrative comparison is a familiarity-based comparison whose purpose is to enhance the hearer\'s understanding of an attribute of the focused entity, by gauging the value for that attribute against the value of the same attribute for another entity which the hearer is familiar with.
ontology of comparisons40

Whole text

Partial text

Bi-focal

Multi-focal

Uni-focal

Direct

comparison

Significant

type

comparison

Domain-based

Familiarity-based

Set Complement

comparison

Clarificatory

comparison

Like-entity

comparison

Illustrative

comparison

Ontology of Comparisons

Comparative text

overview41
Overview
  • The Basic Ideas
  • Language Technology
  • Some Definitions
  • An Ontology of Comparisons
  • Comparison in Context
  • Conclusions and Future Directions
context of discourse

Background

Knowledge

Purpose

Previous

Discourse

Speaker

Hearer

Audience

Familiarity-based

comparison

Domain-based

comparison

Participants

Event

Time

Place

Objects

Topic

Setting

Objects

Message form

Context of Discourse

Discourse

Firth 1957, Hymes 1962, Lewis 1972, Brown & Yule 1983

objects and the hearer
Objects and the Hearer
  • Relationship to the focused entity:
    • similarity
    • relatedness
    • spatial proximity
  • Hearer information:
    • goals
    • knowledge
    • perceivability
creating the context

W

V

Opportunistic

Links

I

User

Knowledge

E

C

Distinguishing

Characteristics

Liken

Distinguish

Creating the Context
example animal domain

Animal

Domain

Domestic Cat

Domestic Dog

Human

f

Cheetah

Leopard,

Cat Class

Distinguishing

Characteristics

Liken

Distinguish

Example - Animal Domain
example jewellery domain

Jewelry

Domain

Other jewels

in this case

Discourse History

Jewels sharing

some property

Opportunistic

Links

Jewel

Instance

Supertype classes

Similar jewels

Distinguishing

Characteristics

Liken

Distinguish

Example - Jewellery Domain
example
Example
  • The Alligator is a member of the Crocodylidae Family that has a broad, flat, rounded snout. It is similar in appearance to the related Crocodile. The Crocodile is a member of the Crocodylidae Family that has a narrow snout. The Crocodile is much longer than the Alligator (5.25 m vs 3.75 m). The Alligator has longer teeth on the lower jaw which cannot be seen when its mouth is closed whereas the Crocodile has one longer tooth on each side of the lower jaw which can be seen sticking up when its jaw is closed.
overview49
Overview
  • The Basic Ideas
  • Language Technology
  • Some Definitions
  • An Ontology of Comparisons
  • Comparison in Context
  • Conclusions and Future Directions
conclusions
Conclusions
  • Analysis of types of comparison
  • Ontology & Definitions
  • Description via comparison
    • Improving hearer’s conceptual coherence
    • Preventing hearer misconceptions
  • Comparisons in context
ad