using controlled natural language and first order logic to improve e-consultation discussion forums...

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Using Controlled Natural Language & First Order Logic to

Improve E-Consultation Discussion Forums

Jodi Schneider

DERI Reading Group2011-09-07Galway, Ireland


Based on 3 Papers (FP7 IMPACT)

A Framework for Enriched, Controlled On-line Discussion Forums for e-Government Policy-making. EGOVIS 2010.Adam Wyner and Tom van Engers. http://wyner.info/research/Papers/WynerVanEngersForum2010.pdf

From Policy-making Statements to First-order Logic. Electronic Government and Electronic Participation 2010. Adam Wyner, Tom van Enger, and Kiavash Bahreini. http://wyner.info/research/Papers/WynerVanEngersBahreini2010.pdf

Towards Web-based Mass Argumentation in Natural Language. (long version of EKAW 2010 poster).Adam Wyner and Tom van Enger. http://wyner.info/research/Papers/WynerVanEngersEKAW2010.pdf

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http://wyner.info/research/Papers/WynerVanEngersForum2010.pdf

http://wyner.info/research/Papers/WynerVanEngersForum2010.pdf

http://wyner.info/research/Papers/WynerVanEngersBahreini2010.pdf

http://wyner.info/research/Papers/WynerVanEngersBahreini2010.pdf

http://wyner.info/research/Papers/WynerVanEngersEKAW2010.pdf

http://wyner.info/research/Papers/WynerVanEngersEKAW2010.pdf


IMPACT Project is developing 4 tools

Argument reconstruction Policy modelling and analysis Structured consultation Argument analysis, tracking and visualization

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Motivation: e-Participation

Policy makers need citizen input. Online forums can garner wide participation. But how can this input be understood and

used?

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Online forum offer challenges!

Disagreement Divergent information Few explicit relationships re: the meaning of

posts Dynamic: the statements and opinions evolve

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Why Knowledge Engineering?

We want citizen input for policymaking to be: Structured Represented Reasoned with Analyzed

Familiar problem: The knowledge acquisition bottleneck

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Extracted 16 sample statements (1)

(1) Every householder should pay tax for the garbage which the householder throws away.

(2) No householder should pay tax for the garbage which the householder throws away.

(3) Paying tax for garbage increases recycling. (4) Recycling more is good.

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Not just statements: Arguments

Households should pay tax for their garbage.

Paying tax for garbage increases recycling, so households should pay.

Recycling more is good, so people should pay tax for their garbage.

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(1)

(4) (1)

(3) (1)



(5) Paying tax for garbage is unfair. (6) Every householder should be charged equally. (7) Every householder who takes benefits does not

recycle. (8) Every householder who does not take benefits pays for

every householder who does take benefits.

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(9) Professor Resicke says that recycling reduces the need for new garbage dumps.

(10) A reduction of the need for new garbage dumps is good.

(11) Professor Resicke is not objective. (12) Professor Resicke owns a recycling company.

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(13) A person who owns a recycling company earns money from recycling.

(14) Supermarkets create garbage. (15) Supermarkets should pay tax. (16) Supermarkets pass the taxes for the garbage to the

consumer.

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Objective: Make policy

Which of these 16 statements are consistent? What are the relationships between pairs of

statements? Which agree? Which contradict?

What policies could be adopted? Consider a “policy” as a set of statements which is

– Consistent– Maximal

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3 theoretical approaches are used

Controlled Natural Language Simplify statements Translate them to First Order Order Logic

First Order Logic Determine consistency

Argumentation Frameworks Find maximal, consistent sets

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Controlled Natural Languages Handle & resolve ambiguity in language

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Man-eating shark Man eating shark


Attempto Controlled English (ACE)

Restricts the words & grammar that can be used Avoid Ambiguity

A customer inserts a card that is valid and opens an account.A card is valid. A customer inserts the card. The customer opens an account.

QuantificationWomen are human.Every woman is a human.

Allows intricate expressions:“A man tries-on a new tie. If the tie pleases his wife then the man buys it.”

Can be translated to First Order Logic Allows consistency checking

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Sample translations to ACE

Original: Every householder should pay tax for the garbage which the householder throws away. (1)

ACE: Every household should pay some tax for the household’s garbage.

Original: A reduction of the need for new garbage dumps

is good. (10) ACE: Every household which reduces a need of a

new dump benefits the household’s society.

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Detailed example of translation

Every householder should pay tax for the garbage which the householder throws away. (1, Original)

Every household should pay some tax for the household’s garbage. (1, ACE)

Use simple, general words“householder” -> “household”

Explicit quantification“tax” -> “some tax”

Relative clauses are turned into possessives

“the garbage which the householder throws away” -> “the household’s garbage”

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Translation issues

Not allowed in ACE:

Every householder should pay tax for garbage which the householder throws away.

Every householder should pay some tax for all of the garbage which the householder throws away.

Misinterpreted: Every household should pay some tax for its

garbage. ACE thinks “its” refers to tax (but we meant the household’s garbage!)

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First Order Logic (FOL)

Universal Quantifier Existence Quantifier

Conjunction Disjunction

= Equality Implication Double Implication¬ Negation

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ACE can be translated to FOL

Every person who writes a book is an author.

AB(person(A) write(A; B) book(B) author(A))

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ACE can also be translated to OWL!

SubClassOf( IntersectionOf( Class(:person) SomeValuesFrom( ObjectProperty(:write) Class(:book))) Class(:author))

Every person who writes a book is an author.AB(person(A) write(A; B) book(B)

author(A))

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Applying FOL to the 16 sentences

With First Order Logic and simplified ACE phrasings, some contradictions become obvious:

(1) Every household should pay some tax for the household’s garbage.

(2) No household should pay some tax for the household’s garbage.

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To fully determine consistency, need more granularity.

Some semantically incompatibilities are still not clear:

(11) Tom is not objective.(9) Tom says that every household which recycles the

household’s garbage reduces a need of a new dump which is for the garbage.

The modeling is not granular enough to detect the inconsistency.

Increasing the internal structure of these arguments is a problem for future work…

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Recall our objectives

Which of these 16 statements are consistent?Need to understand the relationships between the statements.

Which agree?

Which contradict? What policies could be adopted?

Consider a “policy” as a set of statements which is– Consistent– Maximal

Look to argumentation theory to find maximal consistent sets from these 16 statements

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Recall: Arguments

(1) Households should pay tax for their garbage.

(4) (1) Paying tax for garbage increases recycling, so households should pay.

(3) (1)Recycling more is good, so people should pay tax for their garbage.

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Arrow: premise


Graphing the Recycling Debate

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Arrow: premiseDashed arrow: attacks


Maximal consistent sets

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Argumentation Framework for the Recycling Debate

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Arrow: attacks


I thought USERS were doing this?!

Use a Semantic Wiki, ACEWiki

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ACEWiki aids input by clarification

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Summary

With Controlled Natural Language & First Order Logic:Modelled 16 statementsChecked pairs for consistency (up to granularity constraints)

With Argumentation Frameworks:Found 4 maximal sets of consistent statements – possible policiesShowed the attacks (inconsistencies) between these policies.

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Questions for Future Work

They envision that participants select the argumentative relationships between statements. e.g. identifying premises, reasons, supporting statements,

and attacking statements. What are the key relationships? Will users be willing to mark these?

How much of the translation to ACE can be automated?

How to handle “invisible semantic incompatibilities”? Can granularity be improved, easily?

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Relation to my work

Argumentation and the Social Semantic Web Similar context: knowledge engineering for web2.0 Similar purpose: understand arguments in-depth Similar machinery?

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Thank you!

Questions, comments, feedback?

For more on IMPACT, see http://www.policy-impact.eu/

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http://www.policy-impact.eu/


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(1) Every householder should pay tax for the garbage which the householder throws away.

(2) No householder should pay tax for the garbage which the householder throws away. (3) Paying tax for garbage increases recycling. (4) Recycling more is good. (5) Paying tax for garbage is unfair. (6) Every householder should be charged equally. (7) Every householder who takes benefits does not recycle. (8) Every householder who does not take benefits pays for every householder who does

take benefits. (9) Professor Resicke says that recycling reduces the need for new garbage dumps. (10) A reduction of the need for new garbage dumps is good. (11) Professor Resicke is not objective. (12) Professor Resicke owns a recycling company. (13) A person who owns a recycling company earns money from recycling. (14) Supermarkets create garbage. (15) Supermarkets should pay tax. (16) Supermarkets pass the taxes for the garbage to the consumer.


a1 = 1,3,4,9,10

(1) Every household should pay some tax for the household’s garbage.

(3) Every household which pays some tax for the household’s garbage increases an amount of the household’s garbage which the household recycles.

(4) If a household increases an amount of the household’s garbage which the household recycles then the household benefits the household’s society.

(9) Tom says that every household which recycles the household’s garbage reduces a need of a new dump which is for the garbage.

(10) Every household which reduces a need of a new dump benefits the household’s society.


a2 = 11,12,13

(11) Tom is not objective. (12) Tom owns a company that recycles some

garbage. (13) Every person who owns a company that

recycles some garbage earns some money from the garbage which is recycled.

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a3 = 2,5,6,7,8,14,15

(2) No household should pay some tax for the household’s garbage.

(5) If a household pays a tax for the household’s garbage then the tax is unfair to the household.

(6) Every household should pay an equal portion of the sum of the tax for the household’s garbage.

(7) No household which receives a benefit which is paid by a council recycles the household’s garbage.

(8) Every household which does not receive a benefit which is paid by a council supports a household which receives a benefit which is paid by a council.

(14) Every supermarket creates some garbage. (15) Every supermarket should pay a tax for the garbage that

the supermarket creates.


a4 = 16

(16) Every tax which is for some garbage which the supermarket creates is passed by the supermarket onto a household.


Research goals of IMPACT

Computational models of argumentation Mining arguments from natural language texts Improved government consultation User-interfaces and visualizations for computational models

of policy argumentation

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