Which of the following approaches begins with the identification of only a few important concepts
and, based on these, the design proceeds, spreading outward ‘radially’?
A.
Inside-out approach
B.
Bottom-up approach
C.
Mixed approach
D.
Top-down approach
Explanation:
Inside-out approach can be regarded as a particular type of bottom-up approach. It begins with the
identification of only a few important
concepts and, based on these, the design proceeds, spreading outward ‘radially’. First the concepts
nearest to the initial concepts are
represented, and a user then moves towards those further away by means of ‘navigation’ through
the specification.
Answer C is incorrect. In a mixed approach, the designer decomposes the requirements into a
number of components, as in the
bottom-up approach, but not to the extent where all the concepts are separated. At the same time,
a skeleton schema is defined containing
the main concepts of the application. This skeleton schema gives a unified view of the whole design
and helps the integration of schemas
developed separately. Then the designer examines separately these main concepts and can proceed
with gradual refinements following the
top-down approach or extending a portion with concepts that are not yet represented following the
bottom-up approach.
Answer B is incorrect. In a bottom-up approach, the preliminary specifications are broken down into
smaller components so that each
component describes a basic fragment of the specifications. These components are then
represented by schemas, some of which may consist of single concepts. The schemas are later
obtained to be integrated together until a final schema is obtained.
Answer D is incorrect. In a top-down approach, a schema is created through a series of successive
refinements, starting from the first schema, which is gradually expanded by using appropriate
modifications that increase the detail of the various concepts. Moving from one level to another, the
schema is modified using some basic transformations called top-down transformation primitives.