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Now we are going to discuss latent and masked defects. So let’s see the difference.
A masked defect is an existing error that has not yet caused a failure just because another error has prevented that piece of the code from being performed. A latent defect is an existing error that has not yet caused a failure because the accurate set of conditions was never met.
Practical explanation of latent errors Let’s imagine that the application is able to print a document either by laser printer or by dot matrix printer. To reach this the application first searches for the laser printer. In the case if it finds a laser printer it uses this one and prints. In the case if it does not find a laser printer, the application searches for dot matrix printer. And if the application finds a dot matrix printer it prints or an error is given. So this application will never search for the dot matrix printer. And the application never got tested for the dot matrix printer. That means the accurate conditions were never met for the dot matrix printer. This is what we call a latent software bug.
Practical explanation of masked errors Now the same application has 2 errors: •
the dot matrix printer search
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http://qatestlab.com/
QATestLab 21, Garmatna str., Kiev, Ukraine ph.: +38(044)277-66-61 http://qatestlab.com/ contact@qa-testlab.com
•
the dot matrix printer print
But as the search of the dot matrix printer fails the print dot matrix printer error is never detected. So the print dot matrix printer error is a masked software bug.
(c) QATestLab, 2011
http://qatestlab.com/