Using Controlled Natural Language and First Order Logic to improve e-consultation discussion forums (DERI reading group talk)

Using Controlled Natural Language & First Order Logic to Improve E-Consultation Discussion Forums Jodi Schneider DERI Reading Group 2011-09-07 Galway, 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

IMPACT Project is developing 4 tools
Argument reconstruction
Policy modelling and analysis
Structured consultation
Argument analysis, tracking and visualization

Motivation: e-Participation
Policy makers need citizen input.
Online forums can garner wide participation.
But how can this input be understood and used ?

Online forum offer challenges!
Disagreement
Divergent information
Few explicit relationships re: the meaning of posts
Dynamic: the statements and opinions evolve

Why Knowledge Engineering?
We want citizen input for policymaking to be:
Structured
Represented
Reasoned with
Analyzed
Familiar problem:
The knowledge acquisition bottleneck

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.

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.
(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.

(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.

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

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

Controlled Natural Languages
Handle & resolve ambiguity in language
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.
Quantification
Women 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

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.

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”

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!)

First Order Logic (FOL)
 Universal Quantifier
 Existence Quantifier
 Conjunction
 Disjunction
= Equality
 Implication
 Double Implication
¬ Negation

ACE can be translated to FOL
Every person who writes a book is an author.
 A  B(person(A)  write(A; B)  book(B)  author(A))

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.
 A  B(person(A)  write(A; B)  book(B)  author(A))

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.

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…

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

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.
Arrow: premise

Graphing the Recycling Debate Arrow: premise Dashed arrow: attacks

Maximal consistent sets

Argumentation Framework for the Recycling Debate Arrow: attacks

I thought USERS were doing this?!
Use a Semantic Wiki, ACEWiki

ACEWiki aids input by clarification

Summary
With Controlled Natural Language & First Order Logic:
Modelled 16 statements
Checked pairs for consistency (up to granularity constraints)
With Argumentation Frameworks:
Found 4 maximal sets of consistent statements – possible policies
Showed the attacks (inconsistencies) between these policies.

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?

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?

Thank you!
Questions, comments, feedback?
For more on IMPACT, see
http://www.policy-impact.eu/

(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.

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

Using Controlled Natural Language and First Order Logic to improve e-consultation discussion forums (DERI reading group talk)

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