Writing Extended Definitions

A formal definition attempts to state as objectively as possible the characteristics that distinguish the item being defined from other things in the same class. Such a definition, however, cannot give the reader a complete picture of the item, and - especially in the case of abstract or complex ideas - definitions must be expanded if they are to be mean­ingful. Such expansions are called extended definitions.

An extended definition may be completely objective or it may in­clude the author's ideas and opinions. The ideas and opinions of the author are most likely to be included in the definition of a concept, such as courage, that different people define differently. This type of definition may be as short as a paragraph or as long as an essay or even a book. It frequently takes the form of several consecutive paragraphs in a longer work.

A formal definition of a term frequently serves as the skeleton of an. extended definition. Additional details and, in some definitions, the author's point of view and ideas serve to flesh out the skeleton. The introductory paragraph of an extended definition generally includes a formal definition of the subject and, especially when the author has a definite point of view to express, may include a thesis statement.

A variety of methods may be used in developing an extended defini­tion. For example, in an extended definition of a triangle, more infor­mation might be given by using a synonym. This synonym might be in the form of a single word or in the form of a phrase:

This simplest of all polygons has had a widespread and enduring in­fluence on human achievement.

Another way of extending the definition is by an illustrative descrip­tion of how it acts or functions:

It is of fundamental importance in architecture and engineering. If three bars are bolted together into a triangle, for example, the re­sulting structure is rigid, unlike a quadrilateral or other polygon. A framework composed of a system of triangles is therefore complete­ly rigid. The triangle is also highly important in astronomy, naviga­tion, and surveying.

Comparison and contrast are also excellent means of expanding a definition:

Like a circle and a square, the triangle is one of the most recogniz­able geometric figures. Unlike them, however, it can assume a number of shapes. It can be equilateral, it can be isosceles or scalene, and either of the latter two can be a right-angle triangle.

A metaphor can help to give the reader a new view of a familiar subject:

The triangle has been called the keystone of geometry because it is the basic figure in that discipline. A multitude of facts about other rectilinear figures have been discovered by first reducing them to their triangular components.

Finally, an extended definition can be made more interesting by a narrative illustration of the significance of your subject:

The symmetry of both the equilateral and the isosceles triangles so fascinated the ancients that many cultures adopted one or the other as a sign of perfection. Because of this association, these triangles easily became associated with divinity, eternity, and the afterlife. The pyramids of Egypt are probably the most famous example of this age-old concept, but the symbolism can still be found today in the Great Seal of the United States that is on the back of every dollar bill.

An extended definition should end with a concluding statement or section that sums up the subject and emphasizes the main idea the writer wishes to leave with the reader.

WORKING WITH THE MODEL

Read the following extended definition.

To describe what a volcano is not is much easier than to give a concise definition of what it is. A volcano is a vent or chimney, which connects a reservoir of molten matter, known as magma, in the depths of the crust of the earth with the surface of the earth. The material ejected through the vent frequently accumulates around the opening, building up a cone called the volcanic edifice. The loftiest mountains on earth are volcanic edifices. The material ejected consists of liquid lava and broken fragments of partially or completely solidified rock as well as great quantities of gases. The gases are the motivating force and the most important factor in volcanic action. Some authors have maintained that the only feature common to all volcanoes is the channel through which the molten or gaseous material reaches the surface, and therefore a volcano should be defined as “the vent through which this material is erupted”. This, however, leaves us in the difficult position of trying to explain that Vesuvius is not really a volcano but merely a mountain built around one! As now used, the term volcano includes both the vent and the accumulation (cone) around it.

Volcanic eruptions vary between two extremes. In one, the lava rises more or less quietly to the surface and overflows the lip of the crater. The gases bubble through the lava and escape undramatically or, in some instances, rush out with sufficient force to form lava fountains hundreds of feet in height. Nevertheless, the lava is not dispersed but flows away as a river.... On the other extreme, tremendous explosions occur in the chimney. As the lava rises into zones of less pressure, it "froths" because of admixture with the rapidly expanding gases, and is ejected in the form of ash and pumice (pyroclastics).... It was this type of eruption that buried Pompeii in the classic eruption of Vesuvius in a.d. 79.... The essential

difference in the two types is in the gas content and the manner in which the gas is released when the magma reaches the surface.... The great majority of the volcanoes of the world are found between the two extremes described, yielding both lava and fragmental products.

Fred M. Bullard Adapted from Volcanoes of the Earth

A. Think about the definition in this essay.

1. What term is defined? Where is the formal definition found? List the three parts of the formal definition.

2. What is the author's purpose in the first sentence? How does it direct the attention of the reader to the formal

definition?

3. What additional information is given in the first paragraph? What information is given in the second

paragraph?

4. Which of the methods mentioned earlier in this lesson did the author use to develop his extended definition?

Show where the author used each one.

5. What main idea did the author leave with you? What information did you gain from this essay?

B. Imagine that you are writing extended definitions similar to the model. Complete each of the statements begun below by using one of these methods of development: comparison or contrast, synonym, narrative, or metaphor.

Jeans are.... Clogs are....

A sports car is.... A totem pole is....

Football is.... Solar heating is....

C. Imagine that you are preparing to write an extended definition of the Atlantic salmon. Read the formal definition and the details below.

‘The Atlantic salmon is an anadromous fish that lives most of its life in the ocean but returns to the same stream in which it was spawned.’

The details are:

· became extinct in Connecticut

· disappearing in Maine

· not overfished

· can jump as high as twelve feet out of the water

· average ten pounds, some reach forty to seventy pounds

· victim of obstacles constructed by people

· 103 seen out of 600,000 released in 1970

1. In what order would you organize these details in your extended definition?

2. Select two of the details and expand each of them by using a different method of development, such as comparison or contrast, synonym, narrative, or metaphor.

SUMMARY

An extended definition gives a fuller, more complex picture of a term than a formal definition can.

An extended definition may be completely objective or it may in­clude the author's ideas and opinions.

An extended definition may be developed by using a variety of methods, such as synonym, metaphor, comparison or contrast, and narrative.

DRAFTING

1). Choose an idea, an object, or an animal to explain by writing an extended definition.

2). List the class to which the term belongs and its distinguishing char­acteristics. Write a formal definition around which you will build.

3). Think about the term that is the subject of your definition. List all the details that set it off from others in its class. List some synonyms which might be substituted.

4). Think about the parts of your subject. List them. Write what it does or how it is used. Write where it is found. Describe the place or some of the places if there are several. Does it have a history?

5). Think about where your subject is found. Write down details that describe this place, or several of the places if there are more than one.

6). Compare the subject to something similar. Contrast it to something different.

7). Recall an experience you or a friend might have had with your subject. Write a summary reminder of the experience.

COMPOSING

Write an extended definition, using your formal definition and the supporting details you have noted. Build your opening paragraph around the formal definition with supporting sentences designed to capture the attention of your reader.

Organize your details into one or more paragraphs. Be sure that your related ideas are grouped together. Write a conclusion that sums up your controlling idea.

REVISING

Read your extended definition carefully. As you read, ask yourself the following questions:

Ø Where is the formal definition located? What is included in its three parts?

Ø What details are part of the extended definition? How do they clarify and extend the definition? What other details might be added?

Ø How are the details grouped? How might this grouping be changed in order to make your definition clearer?

Ø Which words, if any, should be replaced with more specific ones?

Ø Which methods have been used to develop the extended definition? What other methods might be used to develop the definition further?

PROOFREADING

Proofread your definition. Follow the steps presented in the Proof­reading Checklist on page 142. Correct any mistakes you have made in organization, spelling, punctuation, and capitalization.

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