several kinds of units may be studied separately. For this purpose we
may discuss five common types of units: (1) examples, (2) incidents, (3)
statistics, (4) scientific and technical processes, and (5) recipes and
directions.

METHODS OF DEVELOPING UNITS. In order to present these units most
effectively, and to vary the form of presentation when occasion demands,
a writer needs to be familiar with the different methods of developing
each one of these types. Four common methods of handling material
within these units are: (1) exposition, narration, or description in
the writer's own words; (2) dialogue; (3) the interview; (4) direct or
indirect quotation. Statistics and recipes may also be given in tabular
form.

When a unit may be developed with equal effectiveness by any one of
several methods, a writer should choose the one that gives variety to
his article. If, for example, the units just before and after the one
under consideration are to be in direct quotation, he should avoid any
form that involves quoted matter.

EXAMPLES. In all types of articles the concrete example is the
commonest and most natural means of explaining a general idea. To
most readers, for instance, the legal provisions of an old age
pension law would be neither comprehensible nor interesting, but a
story showing how a particular old man had been benefited by the law
would appeal to practically every one. That is, to explain the
operation and advantages of such a law, we give, as one unit, the
concrete example of this old man. Actual examples are preferable to
hypothetical ones, but the latter may occasionally be used when real
cases are not available. Imaginary instances may be introduced by