Argumentation Structures and Argument Component Types

Types

Assigning an argumentative type to argument components is unambiguous if the argumentation structure is shallow. For instance, it is obvious that an argument component a1 is a premise and an argument component a2 is a claim, if a1 sup-

ports a2 in a basic structure (cf. Section 2.1.3). However, if the structure is deeper,

assigning types becomes ambiguous. Basically there are three different approaches for assigning an argumentative type to the argument components in deeper struc- tures. First, according to Beardsley (1950) a serial argument structure includes an argument component which is both a claim and a premise for another claim. Therefore, the inner argument component has two different argumentative types (multi-label-approach). Second, Govier (2010) distinguishes between “main claim” and ”subclaim”. Similarly, Damer (2009) differntiates between “premise” and “sub- premise” in order to label deeper argument structures. Both approaches define a particular label for each level in the argument structure (level-approach). Third, Co-

Chapter 4. Annotating Argumentation Structures

hen (1987) considers only the root node of an argument as a claim and the remaining nodes in the structure as premise (one-claim-approach). In order to define an an- notation scheme for persuasive essays, we propose a hybrid approach that combines the level-approach and the one-claim-approach.

4.1.4

Argumentation Structure of Persuasive Essays

We model the argumentation structure of persuasive essays as a tree structure and employ a level-approach for modeling the first level of the tree and a one-claim- approach for representing the structure of each individual argument, i.e. the subtrees connected to the root node. Accordingly, we model the first level of the argumen- tation structure with two different argument component types and the structure of individual arguments using argumentative relations.

The major claim, the root node of the argumentation structure, represents the author’s standpoint on the topic (Whitaker, 2009, p. 7). It is an opinionated state- ment that is usually present in the introduction and restated in the conclusion of an essay. The body paragraphs of an essay include the actual arguments. They either support or attack the author’s standpoint expressed in the major claim. Each argument consists of a claim and several premises. For differentiating between sup- porting and attacking arguments, each claim includes a stance attribute that can take the values “for” or “against”.

We model the structure of each argument using a one-claim-approach. The claim constitutes the central component of each argument. The premises are the reasons of the argument. The actual structure of an argument is constituted by directed argumentative support and attack relations. They link each premise either to a claim or to another premise (serial arguments). Note that the equivocal role of the inner premise in a serial argument is implicitly encoded by the structure of the argument (the inner premise exhibits one outgoing relation and at least one incoming relation). The stance of each premise is indicated by the type of its outgoing relation which can either be a support relation or an attack relation.

We refer to this structure as argumentation structure since it does not only model a single argument but several arguments in a single tree structure. In contrast to other models (cf. Section 3.1), our annotation scheme also considers the relations of each argument to the author’s standpoint, i.e. relations from claims to major claims. By doing so, our annotation scheme combines micro-level and macro-level perspectives and allows for modeling the entire argumentation structure of an essay. In the following, we illustrate our annotation scheme by applying it to an example essay.2

Persuasive essays usually include four to six paragraphs (Botley, 2014). The in- troduction, i.e. the first paragraph, describes the controversial topic and includes the major claim (Whitaker, 2009). The following paragraph illustrates an introduction of an essay about cloning:

“Since researchers at the Roslin Institute in Edinburgh cloned an adult sheep, there is an ongoing debate if cloning technology is morally and eth-

2 _{Note that the example essay was written by the author to illustrate all phenomena of argumen-}

4.1. Annotation Scheme

ically right or not. Some people argue for and others against and there is still no agreement whether cloning technology should be permitted. How- ever, as far as I’m concerned, [cloning is an important technology for humankind]M ajorClaim1 since [it would be very useful for developing

novel cures]Claim1.”

The first two sentences introduce the topic and do not include any argumentative content. The third sentence includes the major claim (boldfaced) and a claim which supports the major claim (underlined). The following body paragraphs of the essay include arguments which either support or attack the major claim and the author’s standpoint respectively. For instance, the following body paragraph includes one argument that supports the positive standpoint of the author on cloning:

“First, [cloning will be beneficial for many people who are in need of or- gan transplants]Claim2. [_:::::::Cloned_::::::::organs_::::will_:::::::match_::::::::::perfectly_:::to_::::the_::::::blood ::::::

group_::::and_:::::::tissue_::of_:::::::::patients]P remise1 since [_::::they_:::::can_::be_:::::::raised_::::::from_:::::::cloned :::::

stem_:::::cells_:::of_::::the_::::::::patient]P remise2. In addition, [_::it_:::::::::shortens_::::the_:::::::::healing :::::::

process]P remise3. Usually, [_:it_:::is_::::::very_:::::rare_:::to_:::::find_:::an_{:::::::::::::}appropriate_:::::::organ ::::::

donor]P remise4 and [_::by_::::::using_:::::::::cloning_::in_::::::order_:::to_::::::raise_::::::::required_::::::::organs_::::the :::::::

waiting_::::::time_::::can_:::be_::::::::::shortened_{:::::::::::::::}tremendously]P remise5.”

The first sentence contains the claim of the argument. It is supported by five premises in the remaining three sentences (wavy underlined). The second sentence includes two premises of which Premise1 supports Claim2 and Premises2 supports

Premise1. Premise3 in the third sentence supports Claim2. The fourth sentence

includes Premise4 and Premise5, both support Premise3. The next paragraph illus-

trates a body paragraph including two arguments:

“Second, [_:::::::::scientists_::::use_:::::::::animals_:::as_::::::::models_::in_::::::order_:::to_::::::learn_::::::about_::::::::human

::::::::

diseases]P remise6 and therefore [cloning animals enables novel develop-

ments in science]Claim3. Furthermore, [_::::::::parents_:::::with_:::no_:::::eggs_::::or_::::::::sperms :::

can_::::::have_:::::::::children_:::::that_::::are_::::::::::::genetically_::::::::related]P remise7. [_:::::Even_::::::same_:::::sex :::::::

couples_::::can_::::::have_::::::::children_:::::::::without_:::the_::::use_:::of_::::::donor_:::::::sperm_:::or_:::::eggs]P remise8.

Consequently, [cloning can help human families to get children]Claim4.”

The first sentence includes the first argument starting with Premise6 followed by

Claim3. The next two sentences include a premise which supports another claim in

the last sentence. Note that both arguments cover different aspects (development in science and cloning humans) which both support the author’s standpoint about cloning. This example illustrates that knowing argumentative relations is important for separating several arguments in a paragraph. The example also shows that argu- ment components frequently exhibit preceding text units that are not relevant to the argument but helpful for recognizing the argument component type. For example, preceding discourse connectors like “therefore”, “consequently”, or “thus” can signal a subsequent claim. Discourse connectors like “because”, “since” or “furthermore” could indicate a premise. We refer to these text units as preceding tokens. The third body paragraph illustrates a contra argument and argumentative attack relations:

Chapter 4. Annotating Argumentation Structures

“Admittedly, [cloning could be misused for military purposes]Claim5. For

example, [_::it_::::::could_:::be_:::::used_:::to_::::::::::::manipulate_::::::::human_::::::genes_:::in_::::::order_:::to_:::::::create

::::::::

obedient_:::::::::soldiers_:::::with_{:::::::::::::::}extraordinary_::::::::abilities]P remise9. However, because

[moral_::::::::::and_::::::::ethical_:::::::values_::::are_{::::::::::::::::}internationally_:::::::shared]P remise10, [_::it_::is_::::::very ::::::::

unlikely_:::::that_::::::::cloning_::::will_:::be_:::::::::misused_::::for_:::::::::militant_::::::::::objectives]P remise11.”

The paragraph begins with a claim against the stance of the author which is sup- ported by Premise9 in the second sentence. The two premises in the third sentence

defend the standpoint of the author. Premise11is an attack of Claim5and Premise10

supports premise11. The conclusion, i.e. the last paragraph restates the major claim

and summarizes the main aspects of the essay:

“To sum up, although [permitting cloning might bear some risks like mis- use for military purposes]Claim6, I strongly believe that [this technology

is beneficial for humanity]M ajorClaim2. It is likely that [this tech-

nology bears some important cures which will significantly improve life conditions]Claim7.”

This conclusion begins with an attacking claim followed by the restatement of the major claim. The last sentence includes another claim restating the most important points of the author’s argumentation. Figure 4.1 illustrates the entire argumentation structure of this example essay. It shows the argumentation structure of all five paragraphs and illustrates the argumentation structure of each individual argument.

Figure 4.1: Argumentation structure of the example essay. Arrows indicate argu- mentative relations. Arrowheads denote argumentative support relations and cir- cleheads attack relations. Dashed lines indicate relations encoded in the stance attributes of claims. “P” denotes premises.

In this section, we answered the first question stated in the introduction of this chapter by introducing an annotation scheme for modeling argumentation structures in persuasive essays. In the following, we seek to answer whether human annotators agree on its application to realistic texts.