LECTURE 3: MODELLING LANGUAGE

Lab report -- due Thursday May 16th 16.00 COGS 4C5 First Year Assignment Box

Annotated account of first two/three computer classes

What achieved; what noticed: insights, bugs

Quality and quantity count.

Last time: Production Systems -- learning

Modelling Language -- Computer Class assignment week 2

MODELLING LANGUAGE

Background

Simple Worked Example

Scope and Non-symbolic representations

BACKGROUND

Machine translation

dictionary approach

parsing and analysis

see e.g. http://rivendel.com/ ric/resources/dictionary.html

Syntax and semantics -- declarative and procedural descriptions

Textual commands and questions and descriptions in constrained worlds

``cheats'' -- Eliza (many current web sites/search engines)

BLOCKS WORLD EXAMPLE

put a green block on a blue block
move the little red block onto a big green block
put a block on the table onto a blue block
put the block on a block on a block on a red block
is the big red block on the small green one
where is the small blue block
put it on the table
put the big green block on it
what is on the big green block
what is on the block on the big green one

FAILING TO COMMUNICATE

Vocabulary	put the tiny green block on the large blue block
Grammar (and vocabulary)	put the small green block gently on the red block
Ambiguity (parsing)	put the block on a block on a block on a red block
Ambiguity (reference)	put the block on a block
Semantics	put the table on the small red blok
Semantics	where is the table

BLOCKS WORLD REPRESENTATIONS

1. Vocabulary and grammar
2. Layout and properties of blocks
3. Effects of individual actions of ``hand''

Winograd, T. (1972) Understanding Natural Language, Academic Press, New York.

BLOCKS WORLD STAGES

1. lexical and grammatical analysis
2. extracting meaning(s)

   

   kind of sentence -- command/question

   

   specific content

3. construction of pattern(s)
4. match pattern onto world to get specific description

   

   for questions -- look up relationships

   

   for commands -- construct plan to achieve description

5. report answer or carry out plan

GRAMMAR

[   [s [v np pp] [wh1 vbe np] [wh2 vbe pp]]
    [np [pn] [det snp] [det snp pp]]
    [snp [noun] [ap noun]]
    [ap [adj] [adj ap]]
    [pp [prep np]]
] -> blocks_grammar;

VOCABULARY

[   [noun   block box table one]
    [wh1    where]
    [wh2    what]
    [pn     it]
    [v      put move pickup putdown]
    [vbe    is]
    [adj    white red blue green big small large little]
    [prep   on onto to over in at under above by]
    [det    each every the a some]
] -> blocks_lexicon;

THE BLOCKS WORLD

[   [isa block objR] [colour red objR]   [size large objR]
    [isa block objr] [colour red objr]   [size small objr]
    [isa block objG] [colour green objG] [size large objG]
    [isa block objg] [colour green objg] [size small objg]
    [isa block objB] [colour blue objB]  [size large objB]
    [isa block objb] [colour blue objb]  [size small objb]
    [objb ison objG]
    [objG ison objR]
    [objR ison table]
    [objg ison table]
    [objr ison objB]
    [objB ison table]
] -> database;

WORDS INTO PATTERNS

where is the large red block

[s  [wh1 where]
    [vbe is]
    [np [det the]
        [snp [ap [adj large]
                 [ap [adj red]]]
             [noun block]]]]

[adj red]     means   [colour red ?x]          (adjrule)
[adj large]   means   [size large ?x]          (adjrule)
[noun block]  means   [isa block ?x]           (nounrule)

[where  [ [isa block ?x] [colour red ?x] [size large ?x] ] ]

RULES OF ACTION -- 1

[[   [operator pick up ?x]
    [preconditions [on_table ?x][clear ?x][empty hand]]
    [additions [holding ?x]]
    [deletions [on_table ?x][clear ?x][empty hand]]]
 [   [operator put down ?x]
    [preconditions [holding ?x]]
    [additions [on_table ?x][clear ?x][empty hand]]
    [deletions [holding ?x]]]

RULES OF ACTION -- 2

 [   [operator stack ?x on ?y]
    [preconditions [holding ?x][clear ?y]]
    [additions [on ?x ?y][clear ?x][empty hand]]
    [deletions [holding ?x][clear ?y]]]
 [   [operator unstack ?x from ?y]
    [preconditions [on ?x ?y][clear ?x][empty hand]]
    [additions [holding ?x][clear ?y]]
    [deletions [on ?x ?y][clear ?x][empty hand]]]
] -> operators;

CONCLUSIONS: MODELLING LANGUAGE

1. Declarative symbolic representations
   1. Vocabulary and grammar
   2. Simple World: Layout and properties of blocks
   3. Changes in the simple world: Effects of individual actions of ``hand'': declarative representations
2. Interpreters for the representations

CONCLUSIONS: MODELLING LANGUAGE SCOPE

Highly restricted notion of language

limited vocabulary, grammar and possible meanings

correct and complete sentences only

limited sense of context

no irony, poetry, socio-cultural analysis etc etc

Non-symbolic approaches

Non-grammaticality of everyday speech

Statistical analysis of written and spoken corpora

Speech I/O