Today, not all testers of software applications read code, but the concept of studying program code as part of a testing effort certainly
is widely accepted. Several factors may affect the likelihood that a given testing and debugging effort will include people actually reading
program code:
the size or complexity of the application, the size of the development team, the timeline for application development
(whether the schedule is relaxed or intense, for example), and, of course, the background and culture of the programming team.
For these reasons, we will discuss the process of non-computerbased testing (“human testing”),
First, it is generally recognized that the earlier errors are found, the lower the costs of correcting the errors and the higher the probability
of correcting the errors correctly. Second, programmers seem to experience a psychological change when computer-based testing
commences. Internally induced pressures seem to build rapidly and there is a tendency to want to “fix this darn bug as soon as possible.”
Because of these pressures, programmers tend to make more mistakes when correcting an error found during computer-based testing than
they make when correcting an error found earlier.