Identifying and Analyzing Arguments in a Text

Argumentation in (Con)Text Symposium, Jan. 4, 2007, Bergen

Evaluating Argumentation

• Take the text of discourse as your evidence.

• Is the selected speech act an argument, a report or an explanation?

• If an argument, what are the premises and conclusions?

• Does it fit an argumentation scheme?

• Apply the scheme to the argument

Reasoning, Argument and Explanation

Reasoning can be used for differing purposes, for example in explanations and arguments. Reasoning is a process of inference in passing from certain propositions known or assumed to be true to other propositions in a sequence (Walton, 1990). Abductive reasoning is inference to the best explanation (Josephsons, 1994). Practical reasoning seeks out a prudential line of conduct for an agent in a particular situation, while theoretical reasoning seeks evidence that counts for or against the truth of a proposition (Walton, 1990).

Basic Scheme for Practical Reasoning

• I have a goal G.

• Bringing about A is necessary (or sufficient) for me to bring about G.

• Therefore, I should (practically speaking) bring about A.

What is an Argument?

An argument is a social and verbal means of trying to resolve, or at least contend with, a conflict or difference that has arisen between two parties engaged in a dialog (Walton, 2007). According to this definition, an argument necessarily involves a claim that is advanced by one of the parties, typically an opinion that the one party has put forward as true, and that the other party questions.

Asking Questions

• The speech act of asking a question is different from the speech act of putting forward an argument.

• Questions don’t make assertions.

• But questions can be loaded.

• So asking a question may not be entirely harmless or free from assertive content.

What is an Explanation?

The new dialectical theory (Walton, 2004) models an explanation as a dialogue between two agents in which one agent is presumed by a second agent to understand something, and the second agent asks a question meant to enable him to come to understand it as well. The model articulates the view of Scriven (2002, p. 49): “Explanation is literally and logically the process of filling in gaps in understanding, and to do this we must start out with some understanding of something.”

How to Tell the Difference

Test to judge whether a given text of discourse contains an argument or an explanation. Take the statement that is the thing to be proved or explained, and ask yourself the following question. Is it taken as an accepted fact, or something that is in doubt? If the former, it’s an explanation. If the latter, it’s an argument.

The Goal of Dialogue is DifferentThe purpose of an argument is to get the hearer to come to accept something that is doubtful or unsettled. The purpose of an explanation is to get him to understand something that he already accepts as a fact.

Deductive, Inductive, and the 3rd Type: Abductive?

Wigmore (1931, p. 20) considered arguments of a kind that are commonly used in collecting evidence in law.

Last week the witness A had a quarrel with the defendant B, therefore A is probably biased against B. A was found with a bloody knife in B’s house, therefore A is probably the murderer of B.

Clue: Backward Reasoning by Explanation?

Abductive Reasoning

• D is a set of data or supposed facts in a case.

•  Each one of a set of accounts A1, A2, . . . An is successful in explaining D.

• Ai is the account that explains D most successfully (best explanation).

•  Therefore Ai is the most plausible hypothesis in the case.

Defeasible Reasoning

• Birds fly.

• Tweety is a bird.

• Therefore Tweety flies.

• Subject to exceptions (penguin, ostrich).

• Based on non-absolute generalizations.

• Nonmonotonic: valid arguments can become invalid by adding premises.

Current List of SchemesCommon schemes include such familiar types of argumentation as argument from sign, argument from example, argument from commitment, argument from a verbal classification, argument from position to know, argument from analogy, argument from precedent, argument from correlation to cause, practical reasoning, abductive reasoning, argument from gradualism, and the slippery slope argument. Other schemes that have been studied include argument from waste (also called sunk costs argument), argument from temporal persistence and argument from appearance. In addition to presumptive schemes, it is possible to treat deductive and inductive forms of argument as schemes.

Argument from Expert Opinion

Argumentation Scheme for Argument from Expert Opinion Major Premise: E is an expert in subject domain S containing statement A. Minor Premise: E asserts that A (in domain S) is true (false). Conclusion: A may plausibly be taken to be true (false).

Critical Questions

1. Expertise Question: How credible is E as an expert source?

2. Field Question: Is E an expert in the field that A is in? 3. Opinion Question: What did E assert that implies A? 4. Trustworthiness Question: Is E personally reliable as a

source? 5. Consistency Question: Is A consistent with what other

experts assert? 6. Backup Evidence Question: Is A’s assertion based on evidence?

Instrumental Scheme for Practical Reasoning

• I have a goal G.

• Bringing about A is necessary (or sufficient) for me to bring about G.

• Therefore, I should (practically ought to) bring about A.

Scheme for Value-based Practical Reasoning

• I have a goal G.

• G is supported by my set of values, V.

• Bringing about A is necessary (or sufficient) for me to bring about G.

• Therefore, I should (practically ought to) bring about A.

AraucariaAraucaria is a software tool for analyzing arguments. It aids a user in reconstructing and diagramming an argument using a simple point-and-click interface. The software also supports argumentation schemes, and provides a user-customizable set of schemes with which to analyze arguments.

Once arguments have been analyzed they can be saved in a portable format called "AML", the Argument Markup Language, which is based on XML.

http://www.computing.dundee.ac.uk/staff/creed/araucaria/

The Animal Freedom Example

The Scalpicin Example

Example of a Hamblin DialogueEach member in the sequence is defined by Hamblin (1971, p. 130) as a triple, n, p,l . n represents the length of the dialogue (the number of moves so far). p is a participant. And l is a what Hamblin calls a locution. Using Hamblin’s notation, a small dialogue with three moves for far could be represented as follows.

Small Dialogue: 0, P0 , L4 ,1, P1, L3 ,2,P0, L2

In the simplest case, there are two participants, called the proponent and the respondent. When either party makes any move (speech act), the rules determine which statements are inserted into, or deleted from that participant’s commitment set. Rules define what kinds of moves can be made and what response move needs to be made just after the other party’s last move. Rules define when a sequence of dialogue successfully realizes the communal goal of the dialogue. Each party has a goal, and the dialogue as a whole has what can be called a communal goal.

Speech Act Moves in a Dialogue

Goal of D ialogue

Respondent's Move

Proponent's Move

Sequenc e of Moves

Post-c ondition

Initial S ituation

Turn-taking

Speec h Ac t

Pre-c ondition

Speec h Ac t

Dialogue Typology

Dialogue

PersuasionInformation

SeekingNegotiation

Critical Discussion

InterviewAdvice

Solicitation

Expert Consultation

Inquiry

Scientific Inquiry

Public Inquiry

Deliberation Eristic

Quarrel

Examples of Dialectical Shifts

• A contractor and homeowner are negotiating on the price of a foundation repair, and they shift to the issue of whether it would be a good idea to install and additional inch of concrete wall.

• During a divorce dispute, the couple are negotiating on who should looks after the children, but the mediator shifts the discussion to a persuasion dialogue on the issue of which party is in the best position to undertake the task of looking after the children. Each side must give reasons, and this shift makes the dialogue less eristic.

o f fe r (P i , O n + 1)

P r re s p o n d s to o ffe r

pe rs ua s ion d ia logue[re a s o n s ]

[n o re a s o n s ] [n o s u c c e s s ]

s t a t e o f ag re e m e n t

[s u c c e s s ]

[a c c e p t ][re je c t ]

pe rs ua s ion d ia logue[re a s o n s ][n o re a s o n s ]

Pr de c ide s:R e so lut io n st ill p o ssible ?

[n o s u c c e s s ]

[s u c c e s s ]

[n o ]s t a t e o f

n on -ag r e e m e n t

P r p r o p o se sc o un t e r - o f f e r

[y e s ]

[y e s ]

[s e t v a lu e : i t o r ]

P r r e que st s r e v ise d o f f e r

[P i re v is e s o ffe r]

[n o ]

[P i d o e s n o t re v is e o ffe r]

Embedding of Persuasion

into Negotiation

Dialogue

Some References

M. Scriven, The Limits of Explication’, Argumentation, 16, 2002, 47-57.B. Verheij, Dialectical ‘Argumentation with Argumentation Schemes’, Artificial Intelligence and Law, 11, 2003, 167-195.  D. Walton, ‘What is Reasoning? What is an Argument?’, Journal of Philosophy, 87, 1990, 399-419. D. Walton, Abductive Reasoning, Tuscaloosa, University of Alabama Press, 2004. D. Walton, Fundamentals of Critical Argumentation, New York, Cambridge University Press, 2006.