Argument map

 ( Map ) 

According to Douglas N. Walton and colleagues, an argument map has two basic components: "One component is a set of circled numbers arrayed as points. Each number represents a proposition (premise or conclusion) in the argument being diagrammed. The other component is a set of lines or arrows joining the points. Each line (arrow) represents an inference. The whole network of points and lines represents a kind of overview of the reasoning in the given argument..." With the introduction of software for producing argument maps, it has become common for argument maps to consist of boxes containing the actual propositions rather than numbers referencing those propositions.

There is disagreement on the terminology to be used when describing argument maps,; but the standard diagram contains the following structures: dependent premises, independent premises, and intermediate conclusions.

Dependent premises or co-premises, where at least one of the joined premises requires another premise before it can give support to the conclusion: An argument with this structure has been called a linked argument.

Independent premises, where the premise can support the conclusion on its own: Although independent premises may jointly make the conclusion more convincing, this is to be distinguished from situations where a premise gives no support unless it is joined to another premise. Where several premises or groups of premises lead to a final conclusion the argument might be described as convergent. This is distinguished from a divergent argument where a single premise might be used to support two separate conclusions.;

Intermediate conclusions or sub-conclusions, where a claim is supported by another claim that is used in turn to support some further claim, i.e. the final conclusion or another intermediate conclusion: In the following diagram, statement 4 is an intermediate conclusion in that it is a conclusion in relation to statement 5 but is a premise in relation to the final conclusion, i.e. statement 1. An argument with this structure is sometimes called a complex argument. If there is a single chain of claims containing at least one intermediate conclusion, the argument is sometimes described as a serial argument or a chain argument.; ;

Each of these structures can be represented by the equivalent "box and line" approach to argument maps. In the following diagram, the contention is shown at the top, and the boxes linked to it represent supporting reasons, which comprise one or more premises. The green arrow indicates that the two reasons support the contention:

Argument maps can also represent counterarguments. In the following diagram, the two objections weaken the contention, while the reasons support the premise of the objection:

Some argument mapping conventions allow for perspicuous representation of inferences.: "Another novel feature of Argumentation.io is its use of inference boxes: whenever a user adds a reason or objection to their map, a box representing the inference is automatically placed between the reason/objection and the claim it supports/opposes." In the following diagram, box 2.1 represents an inference, labeled with the inference rule modus ponens.

An inference can be the target of an objection. Such inference objections highlight invalid or weak inferences."Inference objection", in: ; In the diagram below, B is the premise, A is the conclusion, and C is an objection to the inference from A to B.

1. Separate statements by brackets and number them.
2. Put circles around the logical indicators.
3. Supply, in parentheses, any logical indicators that are left out.
4. Set out the statements in a diagram in which arrows show the relationships between statements.

Beardsley gave the first example of a text being analysed in this way:

Though ① people, ② music. For ③ propaganda: (for) ④ look. What is more important, ⑤ art, because ⑥ the.

Beardsley said that the conclusion in this example is statement ②. Statement ④ needs to be rewritten as a declarative sentence, e.g. "Academic monstrosities were produced by the official Nazi painters." Statement ① points out that the conclusion isn't accepted by everyone, but statement ① is omitted from the diagram because it doesn't support the conclusion. Beardsley said that the logical relation between statement ③ and statement ④ is unclear, but he proposed to diagram statement ④ as supporting statement ③.

More recently, philosophy professor Maralee Harrell recommended the following procedure:

1. Identify all the claims being made by the author.
2. Rewrite them as independent statements, eliminating non-essential words.
3. Identify which statements are premises, sub-conclusions, and the main conclusion.
4. Provide missing, implied conclusions and implied premises. (This is optional depending on the purpose of the argument map.)
5. Put the statements into boxes and draw a line between any boxes that are linked.
6. Indicate support from premise(s) to (sub)conclusion with arrows.

An argument map, unlike a decision tree, does not tell how to make a decision, but the process of choosing a Coherentism position (or reflective equilibrium) based on the structure of an argument map can be represented as a decision tree.See section 4.2, "Argument maps as reasoning tools", in

However, the technique did not become widely used, possibly because for complex arguments, it involved much writing and rewriting of the premises.

Legal philosopher and theorist John Henry Wigmore produced maps of legal arguments using numbered premises in the early 20th century, based in part on the ideas of 19th century philosopher Henry Sidgwick who used lines to indicate relations between terms.

Monroe Beardsley proposed a form of argument diagram in 1950. His method of marking up an argument and representing its components with linked numbers became a standard and is still widely used. He also introduced terminology that is still current describing convergent, divergent and serial arguments.

Stephen Toulmin, in his groundbreaking and influential 1958 book The Uses of Argument, (first published 1958) identified several elements to an argument which have been generalized. The Toulmin method is widely used in educational critical teaching.; Whilst Toulmin eventually had a significant impact on the development of informal logic he had little initial impact and the Beardsley approach to diagramming arguments along with its later developments became the standard approach in this field. Toulmin introduced something that was missing from Beardsley's approach. In Beardsley, "arrows link reasons and conclusions (but) no support is given to the implication itself between them. There is no theory, in other words, of inference distinguished from logical deduction, the passage is always deemed not controversial and not subject to support and evaluation". Toulmin introduced the concept of warrant which "can be considered as representing the reasons behind the inference, the backing that authorizes the link".

Beardsley's approach was refined by Stephen N. Thomas, whose 1973 book Practical Reasoning In Natural Language (first published 1973) introduced the term linked to describe arguments where the premises necessarily worked together to support the conclusion. However, the actual distinction between dependent and independent premises had been made prior to this. The introduction of the linked structure made it possible for argument maps to represent missing or "hidden" premises. In addition, Thomas suggested showing reasons both for and against a conclusion with the reasons against being represented by dotted arrows. Thomas introduced the term argument diagram and defined basic reasons as those that were not supported by any others in the argument and the final conclusion as that which was not used to support any further conclusion.

Michael Scriven further developed the Beardsley-Thomas approach in his 1976 book Reasoning. Whereas Beardsley had said "At first, write out the statements...after a little practice, refer to the statements by number alone" Scriven advocated clarifying the meaning of the statements, listing them and then using a tree diagram with numbers to display the structure. Missing premises (unstated assumptions) were to be included and indicated with an alphabetical letter instead of a number to mark them off from the explicit statements. Scriven introduced counterarguments in his diagrams, which Toulmin had defined as rebuttal. This also enabled the diagramming of "balance of consideration" arguments.

In 1998 a series of large-scale argument maps released by Robert E. Horn stimulated widespread interest in argument mapping.; ; Robert E. Horn, "Infrastructure for navigating interdisciplinary debates: critical decisions for representing argumentation", in

In the middle to late 1980s, hypertext software applications that supported argument visualization were developed, including NoteCards and gIBIS; the latter generated an on-screen graphical hypertextual map of an issue-based information system, a model of argumentation developed by Werner Kunz and Horst Rittel in the 1970s., on gIBIS; , on NoteCards; , on the place of both in the history of computer-supported argument visualization In the 1990s, Tim van Gelder and colleagues developed a series of software applications that permitted an argument map's premises to be fully stated and edited in the diagram, rather than in a legend. Van Gelder's first program, Reason!Able, was superseded by two subsequent programs, bCisive and Rationale.

Throughout the 1990s and 2000s, many other software applications were developed for argument visualization. By 2013, more than 60 such software systems existed. In a 2010 survey of computer-supported argumentation, Oliver Scheuer and colleagues noted that one of the differences between these software systems is whether collaboration is supported. In their survey, single-user argumentation systems included Convince Me, iLogos, LARGO, Athena, Araucaria, and Carneades; small group argumentation systems included Digalo, QuestMap, Compendium, Belvedere, and AcademicTalk; community argumentation systems included Debategraph and Collaboratorium. Free and open source structured argumentation systems include Argdown and Argüman.

As of 2020, the commercial website Kialo is the most widely adopted argumentation-based deliberation system with an argument-map interface. On Kialo, users can usually vote on the debate question to express their overall conclusion about the subject, with the average and a bar chart of these votes being included at the top of every debate. Moreover, users can rate the impact individual arguments at the top level had on their conclusion. In branches beneath the top level, users can likewise rank the impact any individual argument has on the claim above it. The Explanation (i.e. the main causal arguments) for their vote on a thesis or an argument is not recorded if these reasons are missing in the claims beneath it or if these have not been rated by the same users. This system of transparent voting represents Kialo's algorithm of collective determination of argument weights and theses' veracities, which has a plurality component in that users of the site can also switch between the perspectives of specific users and several groups of users (e.g. supporters and opponents of a thesis) which for example enables identifying which arguments were considered as most impactful for these particular users. In the context of historical-political education, researcher Oliver Held identified at least five key components of historical judgment that can be implemented easily in Kialo: perspectivity, levels of relevance, interdependence, multi-causality and assessments.