Presupposition

Presuppositions are real-world factors of the communicative situation presumed to be known to the participants. The real problem for the translator results from the divergence in cultural background between the target text and the source text addressees. Presuppositions are closely connected with cultural literacy. Cultural literacy is the ability to converse fluently in the idioms, allusions, and informal content that creates and constitutes a dominant culture. From being familiar with street signs to knowing historical references to understanding the most recent slang, literacy demands interaction with the culture and reflection of it. Knowledge of a canonical set of literature is not sufficient in and of itself when engaging with others in a society, as life is interwoven with art, expression, history, and experience. Cultural literacy requires familiarity with a broad range of trivia and implies the use of that trivia in the creation of a communal language and collective knowledge. Cultural literacy stresses the knowledge of those pieces of information that content creators will assume the audience already possesses.

Compositional categories

Macrostructure of the text

In linguistics and discourse analysis semantic macrostructures are the overall, global meanings of discourse, usually also described in terms of topic, gist, or upshot. These semantic macrostructures (global meanings or topics) are typically expressed in for instance the headlines and lead of a news report, or the title and the abstract of a scholarly article. Macrostructures of discourse are distinguished from its microstructures, that is, the local structures of words, clauses, sentences or turns in conversation. Macrostructures may be derived from microstructures by operations such as abstracting that is, leaving out or summarizing specific details. Semantic macrostructures or topics define what is called the global coherence of discourse.

The macrostructure of a text is first and foremost signaled by formal devices used to mark the boundaries of segments of both written and spoken discourse which form large units, such as chapters or paragraphs. Chapters are marked by chapter headings or numerals, paragraphs by indentations. These non-verbal markers are often combined with lexical markers, e.g. adverbial clauses in initial (first-then-finally) or focused position (on the one hand- on the other hand).

Macrostructures are defined by the following principles:

• The interpretation of certain units is defined in terms of the interpretation of their constituent parts;

• Macrostructures consist of propositions, namely macropropositions;

• Macrorules relate proposition sequences with proposition sequences at a higher level, and this derives the global meaning of an episode or whole discourse from the local, sentential meaning of the discourse;

• Macrorules are recursive, so the notion of macroproposition is relative; the resulting macrostructure of a discourse is a hierarchical structure.

Three macrorules are pointed out:

DELETION: Given a sequence of propositions, delete each proposition that is not an interpretation condition for another proposition in the sequence.

GENERALIZATION: Given a sequence of propositions, substitute the sequence by a proposition that is entailed by each of the propositions of the sequence.

CONSTRUCTION: Given a sequence of propositions, replace it by a proposition that is entailed by the joint set of propositions of the sequence.

Being a dynamic model of text and discourse understanding, a macrostructure is complexity oriented, i.e. strategic. The overall strategy aims to construct a textbase, the semantic representation of the input discourse in episodic memory. Textbases are defined in terms of propositions and relations among propositions. All strategically constructed macropropositions form the macrostructure of a text. Macrostructures are structures of discourse from which they are inferred, they are often directly expressed in the discourse, signaled by titles, thematic sentences, key words, and so on.

Cohesion and coherence

Cohesion is a term from the work on textual structure by Halliday and Hasan, given to the logical linkage between textual units, as indicated by overt formal markers of the relations between texts. In English, cohesion is most simply marked by connectives such as and, but, or so. Each piece of text must be cohesive with the adjacent ones for a successful communication. However, readers are very creative interpreters, and formal properties of cohesion are typically not marked overtly.

Cohesion is defined as the use of explicit linguistic devices to signal relations between sentences and parts of texts. These cohesive devices are phases or words that help the reader associate previous statements with subsequent ones. Scholars identify five general categories of cohesive devices that signal coherence in texts:

• reference

• ellipsis

• substitution

• lexical cohesion

• conjunction

A text may be cohesive without necessarily being coherent: Cohesion does not spawn coherence. Cohesion is determined by lexically and grammatically overt intersentential relationships, whereas coherence is based on semantic relationships.

Coherence is a way of talking about the relations between texts, which may or may not be indicated by formal markers of Cohesion. For example, advertising language tends not to use clear markers of Cohesion, but is interpreted as being Coherent.

Coherent texts make sense to the reader. Coherence is a semantic property of discourse formed through the interpretation of each individual sentence relative to the interpretation of other sentences, with "interpretation" implying interaction between the text and the reader. One method for evaluating a text's coherence is topical structure analysis.