When it comes in writing an exposition, it is very important that the readers knows what the writer or the author is talking about. In here, it shows the importance of the definition, it is the kind of exposition most naturally to begin with.
There are two main types of definition namely; the logical or formal definition and the extended or informal definition. The logical and the extended definition differ from their own way and purpose.
The logical or formal definition is considered as the dictionary definition. There are three essential parts of this definition namely the “term” or the word to be defined, the “genus” which limits the particular terms to a restricted class and the “differentiae” that states the characteristics which distinguish a defined species from the other members of each of the gems.
There are certain types of errors usually occur when constructing a logical definition. One is when the term being defined is included in the defining part; this could make the definition as circular one. Second is by giving a negative definition to a particular term, this should not be done unless some of its idea are considered as an essential to the term’s meanings. The third one is by giving a figurative definition to a particular term.
The extended or informal definition is done in an informal or in more flexible development means. There are reasons why extended or informal definitions are made by writers. One is that when the writer thinks or fells that the real definition of a particular term is distorted in the minds of the public, here extended definition is needed as replacement for the real defition. Another is that it is used in removing confusions as well as to make the context more precise. Extended definition is also use to set up an ideal meaning that is in contrast with the other meaning that merely reflects an existing fact.
There are four forms of extended definitions namely; the historical definition, the definition by elimination, the definition by example and illustration, and definition by enumerating the part of an object or the factors that produced a particular effects.
Giving a definition is an important thing to consider especially when writing an exposition. Before a writer or an author say about something, he or she must give emphasis with regards to the definition of that particular thing in order to guide the readers what the composition is all about.