DESCRIPTION is one of four rhetorical modes (also known as modes of discourse), along with exposition, argumentation, and narration. Each of the rhetorical modes is present in a variety of forms and each has its own purpose and conventions.
Description is also the fiction-writing mode for transmitting a mental image of the particulars of a story.
Description as a fiction-writing mode
Fiction is a form of narrative, one of the four rhetorical modes of discourse. Fiction-writing also has distinct forms of expression, or modes, each with its own purposes and conventions. Agent and author Evan Marshall (agent) identifies five fiction-writing modes: action, summary, dialogue, feelings/thoughts, and background (Marshall 1988, pp. 143–165). Author and writing-instructor Jessica Page Morrell lists six delivery modes for fiction-writing: action, exposition, description, dialogue, summary, and transition (Morrell 2006, p. 127). Author Peter Selgin refers to methods, including action, dialogue, thoughts, summary, scene, and description (Selgin 2007, p. 38). Currently, there is no consensus within the writing community regarding the number and composition of fiction-writing modes and their uses.
Description is the fiction-writing mode for transmitting a mental image of the particulars of a story. Together with dialogue, narration, exposition, and summarization, description is one of the most widely recognized of the fiction-writing modes. As stated in Writing from A to Z, edited by Kirk Polking, description is more than the amassing of details; it is bringing something to life by carefully choosing and arranging words and phrases to produce the desired effect. (Polking, p. 106) The most appropriate and effective techniques for presenting description are a matter of ongoing discussion among writers and writing coaches.
Purple prose is a term of literary criticism used to describe passages, or sometimes entire literary works, written in prose so overly extravagant, ornate, or flowery as to break the flow and draw attention to itself. Purple prose is sensually evocative beyond the requirements of its context. It also refers to writing that employs certain rhetorical effects such as exaggerated sentiment or pathos in an attempt to manipulate a reader's response.
Kinds of Description
Description is primarily of two kinds, that which is to give accurate information, and that which is to produce a definite impression not necessarily involving exactness of imagery. The first of these forms is useful simply in the way of explanation, serving the first purpose indicated in paragraph four. The second is useful for other purposes than that of exposition, often appealing incidentally to our sense of the beautiful, and requiring always nice literary skill in its management. It should be borne in mind always that literary description must not usurp the office of representations of the material in the plastic arts. It should not be employed as an end in itself, but only as subsidiary to other ends
NARRATION is assimilating information and retelling it. Anyone would listen closely if they knew they were going to retell what they had heard. Just like when you've seen a documentary and tell your friend all about it the next day, you will remember it better.

Charlotte Mason uses an illustration of a doctor visiting a sick person in the hospital. The patient is in extreme pain and the doctor has written the remedy on a three-by-five card. He tells her this will alleviate the pain, however, he's only going to let her look at the card for a few minutes. Then the card will be destroyed permanently, and he won't be writing it for her ever again. Can you imagine the attention you would give to that card? This is the kind of attention Charlotte wants the children to pay to their reading. When they are retelling they have to leave some information out and that's one of the choices being made by their minds. Charlotte says it is not a mere act of memory because we let their minds act on the material in their own original way. They will classify and connect information. Remember, you cannot narrate what you do not know. If you can narrate it, you know it.

Narration can be used in all school subjects and in all experiences. Charlotte says years later the child will be able to narrate the same passage with "vividness, detail and accuracy of the first telling."

Setting
Where did the story take place?
When did it take place? Characters
Who are the main characters in the story?
What can you tell me about them? Problem(s)
What problem(s) did the main character have to solve? Goal
What is the main character’s goal?
What is he/she trying to do? Plot
What are the main things that happened in the story? Outcome
How was the story problem resolved?

A Narrative Essay Should:
Establish 4 w’s in setting, in context of action
Show rather than tell
Begin at the beginning – End at the end
Build to a climax – bring action to a close
Prolong exciting parts – Shorten routine facts
Use sequencing or logical order
Have a certain audience
Have a clear point of view in terms of:
Person: Who will tell the story?
Attitude: Personal feelings
Vantage point of narrator

ARGUMENTATION is an international and interdisciplinary journal that gathers academic contributions from a wide range of scholarly backgrounds and approaches to reasoning, natural inference and persuasion: communication, classical and modern rhetoric, linguistics, discourse analysis, pragmatics, psychology, philosophy, formal and informal logic, critical thinking, history and law. Its scope includes a diversity of interests, from philosophical, theoretical and analytical to empirical and practical topics.
Argumentation publishes papers, book reviews, a yearly bibliography, and announcements of conferences and seminars.
"Argumentation is a verbal, social, and rational activity aimed at convincing a reasonable critic of the acceptability of a standpoint by putting forward a constellation of one or more propositions to justify this standpoint. . . .

"Argumentation relates both to the process of putting forward argumentation and to its 'product,' and the term argumentation covers the two of them. . . .

"People who make use of argumentation always appeal--whether explicitly or implicitly--to some standard of reasonableness. This, however, does not always mean that each argumentation is indeed reasonable."

Argument – Argument is a group of statements, one of which is claimed to follow from the others.

1.) An argument consists of at least two statements, one that is claimed to follow, called the conclusion, and at least one another, called the premise, that is claimed to support the conclusion.

2.)Every argument involves at least one inference – the inference from the premise to the conclusion.

3.) An argument involves a claim that one statement follows from the others, that is an argument purports to show that something is true.

An argument therefore is not a mere collection of propositions but contains a premise-conclusion structure. The simplest kind of argument consists of just one premise and a conclusion. Here is an example in which each is stated in a separate sentence:

EXPOSITION is a type of oral or written discourse that is used to explain, describe, give information or inform. The creator of an expository text can not assume that the reader or listener has prior knowledge or prior understanding of the topic that is being discussed. One important point to keep in mind for the author is to try to use words that clearly show what they are talking about rather then blatantly telling the reader what is being discussed. Since clarity requires strong organization, one of the most important mechanisms that can be used to improve our skills in exposition is to provide directions to improve the organization of the text. What are some Expository Organizational Patterns
In order to give you more information about oral and written exposition we have provided you with eight different examples of expository organizational patterns. You will find that most of these organizational patterns are very familiar to you. You may have never really considered them to be "kind" of organizational patterns. As you read through the different types of organizational patterns that are presented below, try to figure out how many of these organizational patterns do you already find yourself writing or speaking on a daily basis? Pattern | Description | Cue Words | Graphical Organizer/Sample Passages | Circumlocution | Depicts a pattern in which the speaker discusses a topic, then diverts to discuss a related but different topic. | | View | Narrative Interspersion | A pattern or a sub-pattern imbedded in other patterns in which the speaker or writer intersperses a narrative within the expository text for specific purposes, including to clarify, or elaborate on a point or to link the subject matter to a personal experience. | | View | Recursion | When the speaker discusses a topic, then restates it using different words or symbolism. It is used to drive home a point and to give special emphasis to the text. | | View | Pattern | Description | Cue Words | Graphical Organizer/Sample Passages | Description | The author describes a topic by listing characteristics, features, and examples | for example, char- acteristics are | View | Sequence | The author lists items or events in numerical or chronological order. | first, second, third; next; then; finally | View | Comparison | The author explains how two or more things are alike and/or how they are different. | different; in contrast; alike; same as; on the other hand | View | Cause and Effect | The author lists one or more causes and the resulting effect or effects. | reasons why; if...then; as a result; therefore; because | View | Problem and Solution | The author states a problem and lists one or more solutions for the problem. A variation of this pattern is the question- and-answer format in which the author poses a question and then answers it. | problem is; dilemma is; puzzle is solved; question... answer | View |

This flexible term describes the variety, the conventions, and the purposes of the major kinds of writing. The four most common rhetorical modes and their purposes are as follows: 1. The purpose of exposition (or expository writing) is to explain and analyze information by presenting and idea, relevant evidence, and appropriate discussion. The AP language exam essay questions are frequently set up as expository topics. 2. The purpose of argumentation is to prove the validity of an idea, or point of view, by presenting sound reasoning, discussion, and argument that thoroughly convince the reader. Persuasive writing is a type of argumentation having the additional aim of urging some form of action. 3. The purpose of description is to re-create, invent, or visually present a person, place, event, or action so that the reader can picture that being described. Sometimes an author engages all five senses in description; good descriptive writing can be sensuous and picturesque. Descriptive may be straightforward and objective or highly emotional and subjective. 4. The purpose of narration is to tell a story or narrate an event or series of events. This writing mode frequently uses the tools of descriptive writing.
These four writing modes are sometimes referred to as modes of discourse.

Examples:

Exposition: * Business letters * Personal letters==== * News stories
Argumentation:
* Critical review * Editorials * Job application letter
Description:
* Poetry * Journal writing * Diary entry
Narrative:
* Autobiography * Short Stories * Oral histories
Source:
http://www.gial.edu/GIALens/vol4-3/Tim%20MacSaveny-Description%20of%20Descriptive%20Discourse.pdf http://www.k-state.edu/english/baker/english320/cc-exposition.htm http://findarticles.com/p/articles/mi_m2342/is_2_34/ai_68279076/pg_2/