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