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selected. In Distinction step, two inputs Iin (inside) and Iout (outside) are gener-
ated such that these two points belong to different sides of border b. The distinction
step is carried out in two phases: the extension phase and the refinement phase. In
the extension phase the size of the step is doubled after each successful move. Also
in the extension phase, when the minimization function becomes negative (or
zero), the required program inputs Iin and Iout have been found. Once the
extension phase is complete, the refinement phase is carried out. Distinction step is
followed by Halving Step. In the Halving Step, the size of the step between Iin and
Iout is halved to get the new input Ih. If F(Ih) is negative (or zero), then Ih replaces
Iout, otherwise Ih replaces Iin. Here we minimize the distance between the input
points obtained in the Distinction Step (Samuel and Mall
2004
).
10.12 Testing for Object-Oriented Systems
Testing being the activity of attempting to elicit results that can be monitored and
analyzed is not wholly sufficient for the object-oriented paradigm. Object-oriented
tests, like object-oriented programming itself, revolves around the concept of
reducing effort while maximizing value. Value in this case is the confidence in the
thoroughness of the tests. This results in a lengthened test design phase and a
shortened test implementation phase.
Elienes outlines three levels of testing when testing object-oriented systems.
The first level as he coins, is the strategic level. At this level there should be risk
assessment. That is, which components of the system need to be evaluated with the
most care, which components do the most other components rely on for func-
tionality and which components are required for fault tolerance. In embedded real
time devices some components may be the difference between a system that saves
lives and one that takes lives. The second portion of the testing revolves around
tactics. However, when and where these modules and objects are going to be tested
will be answered. Plans based on the risk assessment should be created. Finally,
the tests are implemented and executed at the operational level (Elienes
1995
).
10.13 Testing in a Box
Testing for either the inside or the outside of a system solely can be deemed testing
from inside a box. This box is merely an analogy for the feeling of either only
having internal or external access to a system. The system is in a sense limited to
you by your access and knowledge. White-box testing is theoretically capable of
finding and correcting all logical errors in the programs structure. However, this is
impossible due to the limited nature of human intelligence. Black box testing on
the other hand, provides a unique insight into the errors that may arise by the
typical use of the system.
