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Rallou Thomopoulos
EPI GraphIK
In collaboration with:
IRIT: L. Amgoud
LIRMM: M.L. Mugnier
IATE: S. Destercke, J. Fortin
PhD thesis: J.R. Bourguet
Argumentation to support
decision in agri-food chains
Context
NutritionSecurity
Taste
Environment
Costs
Easy-to-use
Technicity
WHAT TO DO ?
Example
T65 ? T80 ?
ConsumersBakersMillers
Government(PNNS)
ResearchersNutritionists
Example
T65 ? T80 ?
Avoiding chemical contamination
Proposing a consumer-attractive bread
Limitating irritating fibers
Maintaining sells
Avoiding the responsability for consumer security
Preserving the profession’s technicity
Increasing nutritional components
Decreasing costs
Limitating salt consumption
Controling appetite
Reducing costly widespread diseases
~60 identified arguments
• Models for formal representation ?
• Support to analyse a complex situation ?
• Methods for arbitration (compromise, …) ?
• Explanations for a decision ?
Questions
Combination of both = emerging issue
2 existing frameworks of interest:
• Argumentation
• Multi-criteria decision
Formal approach
• Abstract argumentation framework (Dung, 1995)
(A,R) with: - A a set of arguments
- R an attack relation
Argumentation
• Other elements: preferences, contexts, …
a b
a b
Argumentation
• An argument consists in:- a set of assumptions (support or premises)
- a conclusion (claim or consequent)
- an implication: the conclusion can be deduced from the assumptions
• Different kinds of attack:- rebutting (negation of the conclusion)
- assumption attack (negation of the assumptions)
- undercutting (negation of the implication)
Prise de décision (Argumentation)
COM1 argument
T65 → T80
Change in color
Change in texture
economical
profit
COM2 argument
T65 → T80awareness campaign
communication on cereal products
economical
profit
Satiety
Decreased sales
health benefitREBUTTING
Example
Prise de décision (Argumentation)
NUTRI1 argument
T65 → T80 phytic acid
biodisponibility of essential cations (Zn,Cu,…)
healthbenefit
NUTRI2 argument
T65 → T80use of natural yeast (sourdough)
Acidity
phytic acid
ASSUMPTION ATTACK
Example
Prise de décision (Argumentation)
PNNS argument (part of)
T65 → T80 Fibers
health benefit
T65 → T80 Fibers
health benefit
insoluble fibers
NUTRI3 argument
UNDERCUTTING
Example
Argumentation
• Several semantics:- naïve extension: no conflicts + maximal- admissible extension: no conflicts + defense- preferred extension: no conflicts + defense + maximal- complete extension: concerns self-defending arguments- stable extension: no conflicts + attacks external arguments- basic extension: recursively defined
• Notion of « extension »
Prise de décision (Argumentation)
Milling argument (MILL)
T65 → T80 extraction rate
production cost
economical
profit
Baking argument (BAK)
T65 → T80 fibers
water flour
economical
profit
Example
Prise de décision (Argumentation)
PREFERRED EXTENSIONS:{COM1, NUTRI3, NUTRI2}{COM2, MILL, BAK, PNNS, NUTRI2}{COM2, MILL, BAK, NUTRI3, NUTRI2}
PNNSNUTRI3
NUTRI1
NUTRI2
MILL
BAK
COM1
COM2
Example
• Argument = {S,d,g} with:
- S the knowledge that supports the argument
- d the supported decision
- g a goal
(Amgoud and Prade, 2009)
Argumentation-based decision
• A simple mode of decision : choose the option that is supported by most "acceptable" arguments
Example
T65 ? T80 ?
Peripheric layers are rich in vitamins and minerals Increasing nutritional components
T65 contains less peripheric grain layers Avoiding chemical contamination
T65 produces more crusty breads Proposing a consumer-attractive bread
T65 contains more soluble fibers Limitating irritating fibers
The market of T65 bread works well Maintaining sells
T65 provides less contammination risks Avoiding the responsability for consumer security
T80 bread requires less flour and more water Decreasing costs
T65 involves complex fractionation steps by millers Preserving the profession’s technicity
T80 is consumed in smaller quantities Limitating salt consumption
T80 increases satiety Controling appetite
(d)
(S)(g)
T80 participates in public health control Reducing costly widespread diseases
First approach:6 arguments versus 5
T65
Example
T65 ? T80 ?
Peripheric layers are rich in vitamins and minerals Increasing nutritional components
T65 contains less peripheric grain layers Avoiding chemical contamination
T65 produces more crusty breads Proposing a consumer-attractive bread
T65 contains more soluble fibers Limitating irritating fibers
The market of T65 bread works well Maintaining sells
T65 provides less contammination risks Avoiding the responsability for consumer security
T80 bread requires less flour and more water Decreasing costs
T65 involves complex fractionation steps by millers Preserving the profession’s technicity
T80 is consumed in smaller quantities Limitating salt consumption
T80 increases satiety Controling appetite
(d)
(S)(g)
T80 participates in public health control Reducing costly widespread diseases
nutritionists’1st goal
bakers’1st goal
government’s1st goal millers’
1st goal
mostconsumers’
1st goal
informedconsumers’
1st goal
Second approach:Satisfying most actors
T80
Unified approach
Example
Example
• A simplified example of a complex situation• Different possible modes of decision• Interest of the approach: theory, applications
and stakes• Sensitive point: dependant on the quality of
arguments identification
Conclusion
• Decision with several viewpoints in the unified approach
• A lot to do to facilitate visual representation and analysis
• Towards a implemented tool
Perspectives