COHERENCE
A research paper is a type of text which is linked logically and structurally. Every text type has structural and language features.It usually contains a series of sentences which are connected by grammar and vocabulary and knowledge of the world, e.g.:
- Disconnected sequences are rather an exception than the rule. Moreover, they do not contradict in the least the idea of a continual topical text as being formed by grammatically interconnected sentences.[M. Blokh 2000]
The second sentence explains why disconnected sentences are rather an exception than the rule. But we can understand this only if we know theoretical grammar. This is our background knowledge. We need to use this knowledge to see the connection between these two sentences (coherence). The grammatical means of connection (cohesion) also help us see this link: in the second sentence “they” refers to “sequences”.
As we have already seen, to write a text we need not only to organize sentences in it, but also to write sentences so that there will be a logical or semantic (topical) link between them, some common theme or topic. A text, whether it is a research paper or a school essay, is a continual succession of sentences centering on a common informative purpose. It is a lingual entity with two main features: semantic unity and semantico-syntactyc cohesion.
Thus, the sentences in a text are linked by the so-called various coherence relations. Let us consider only the most important types of these relationships:
Ø parallel
- N.S.Pospelov put forward the cited principle and B.A.Ilyish pointed out serious advantages of it.[M. Blokh 2000]
Ø description
A theme is split up into its components; it is specified and situated in space and time. The descriptive theme development either refers to a unique historical event (i.e. in news and reports), a process that is generalized or repeated (i.e. found in recipes, encyclopedia entries, manuals etc.), or the description of either a living creature or an object (as found, for instance, in dictionary articles)
Ø narration
It is especially found in recounting of everyday situations, in newspaper articles, in narratives etc.; the elements in a narrative are usually ordered according to the linear order of the events described
Ø clarification, contrast
- The other type of relations is called paradigmatic which exist between elements of the system outside the strings where they occur. These relations find their expression in the fact that each lingual unit is included in a set or series of connections based on different formal and functional properties. Unlike paradigmatic relations, syntagmatic relations are observed in the following utterances (…)[M. Blokh 2000]
Ø explication
- The systematic nature of grammar is probably more evident than that of any other sphere of language. Due to this fact, even the earliest grammatical treaties disclosed systematic features of the described material.[M. Blokh 2000]
Ø temporal relation
A temporal relation can be marked both explicitly (i.e. by cohesive ties) and implicitly (inferred by the reader)
- First of all we should analyze the grammar and the structure of the sentence for some time and only then do the translation. [M. Blokh 2000]
Ø cause-effect-relation
- The phoneme has no meaning, its function is purely differential. Since the phoneme has no meaning, it is not a sign. (result).[M. Blokh 2000]
- The syllable is not a sign. It has a purely formal significance. (explanation). [M. Blokh 2000]
Ø argumentation
The speaker or writer introduces an argument and backs it up by supporting facts or other pieces of evidence:
The introduction of genetically modified (GM) food and crops has been a disaster. The science of taking genes from one species and inserting them into another poses a serious threat to biodiversity and our own health. In addition, the real reason for their development has not been to end world hunger but to increase the stranglehold multinational biotech companies already have on food production (...).[https://www.genejury.biology.ed.ac.uk/GMGreenpeace.pdf]
To sum it up, a text has coherence if its constituent sentences follow on one from the other in an orderly fashion so that the reader can make sense of the entire text.
COHESION
As we have already noted, coherence deals with internal (logic-semantic) relationships between the sentences (connection in meaning), whereas cohesion refers to external (syntactic-semantic) relationships (connection in grammar and vocabulary).
The major function of cohesion is text formation. There are different types of cohesive relations which represent relations between two or more elements in a text which are independent of the structure: for example, a personal pronoun and an antecedent proper name, such as John…he. Let us consider the most important cohesive devices in the text:
Ø reference
The next higher unit is the phrase. It is located at the phrasemic level. [M. Blokh 2000]
There are three referential devices that can create cohesion:
Ø anaphoric reference occurs when the writer refers back to someone or something that has been previously identified, to avoid repetition.
Ø cataphoric reference is a reference forward. Something is introduced in the abstract before it is identified. Cataphoric references can also be found in written text, for example, “ see page 10 ”.
Ø exophoric reference is used to describe abstracts without ever identifying them rather than introduce a concept, the writer refers to it by a generic word such as “everything”. The prefix “exo” means “outside”, and the persons or events referred to in this manner will never be identified by the writer.
Ø substitution
A word is not omitted, as in ellipsis, but is substituted for another, more general word. For example, “ Functional words are exposers of various types of syntactic categories. The ones that we have come across in our study show that they render structural meanings… ” [M. Blokh 2000], where “one” is used instead of repeating “functional words”. This works in a similar way to pronouns, which replace the noun.
Ø ellipsis
Ellipsis is another cohesive device. It happens when, after a more specific mention, words are omitted when the phrase needs to be repeated.
- Can these phenomena signify that that the sentence is simply a sub-unit in language system […]? – In no wise. [M. Blokh 2000]
- Some statements that we make in our research article are facts and some are opinions. [M. Blokh 2000]
- There are two notions within the framework of the structural hierarchy of language: word and sentence. The first is analysed by morphology and the second is analysed by syntax. [M. Blokh 2000]
Ø conjunction
- It has its word-building distinctions and it discriminates the grammatical categories of gender, number, case […].[M. Blokh 2000]
Conjunction sets up a relationship between two clauses. The most basic but least cohesive is the conjunction and.
Transitions are conjunctions that add cohesion to text and include then, however, in fact, consequently, etc.
- The form of the verbal past tense is built up by the suffix “–ed”. However, the past tense is expressed not by the dental morpheme in isolation, but by the verb taken in the corresponding form. [M. Blokh 2000]
Conjunctions can also be implicit and deduced from correctly interpreting the text.
Ø lexical cohesion
Lexical cohesion comes about through the selection of lexical items that are related in some way to those that have come before. Lexical cohesion is created by reiteration and collocation.
Reiteration includes repetition of a lexical item, the use of synonyms or general words to refer back to a lexical item:
- The verb is in the past tense.
- The word is in the past tense.
- The predicate is in the past tense.
- The sentence unit is in the past tense.
Collocations are words or word combinations that tend to occur together (heavy rain, wrong way, find out, etc).
As you have understood, cohesion is expressed partly through grammar and partly through vocabulary.
A text can be coherent without being cohesive, and vice versa. Thus, the reader can still perceive coherence in a sequence of clauses and sentences even if the semantic and syntactic ties connecting them are missing. On the other hand, even if a text shows a strong degree of cohesion, with its constituents being interlinked by many cohesive ties, it does not need to be coherent.That is why the understanding of both coherence and cohesion is necessary when writing a research article.