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Good partitioning requires knowledge of the software structure. A good testing plan will not only contain black-box testing, but also white-box approaches, and combinations of the two.

White-box testing

Contrary to black-box testing, software is viewed as a white-box, or glass-box in white-box testing, as the structure and flow of the software under test are visible to the tester. Testing plans are made according to the details of the software implementation, such as programming language, logic, and styles. Test cases are derived from the program structure. White-box testing is also called glass-box testing, logic-driven testing or design-based testing.

There are many techniques available in white-box testing, because the problem of intractability is eased by specific knowledge and attention on the structure of the software under test. The intention of exhausting some aspect of the software is still strong in white-box testing, and some degree of exhaustion can be achieved, such as executing each line of code at least once (statement coverage), traverse every branch statements (branch coverage), or cover all the possible combinations of true and false condition predicates (Multiple condition coverage).

Control-flow testing, loop testing, and data-flow testing, all maps the corresponding flow structure of the software into a directed graph. Test cases are carefully selected based on the criterion that all the nodes or paths are covered or traversed at least once. By doing so we may discover unnecessary "dead" code - code that is of no use, or never get executed at all, which can not be discovered by functional testing.

In mutation testing, the original program code is perturbed and many mutated programs are created, each contains one fault. Each faulty version of the program is called a mutant. Test data are selected based on the effectiveness of failing the mutants. The more mutants a test case can kill, the better the test case is considered. The problem with mutation testing is that it is too computationally expensive to use. The boundary between black-box approach and white-box approach is not clear-cut. Many testing strategies mentioned above, may not be safely classified into black-box testing or white-box testing. It is also true for transaction-flow testing, syntax testing, finite-state testing, and many other testing strategies not discussed in this text. One reason is that all the above techniques will need some knowledge of the specification of the software under test. Another reason is that the idea of specification itself is broad - it may contain any requirement including the structure, programming language, and programming style as part of the specification content.

We may be reluctant to consider random testing as a testing technique. The test case selection is simple and straightforward: they are randomly chosen. Random testing is more cost effective for many programs. Some very subtle errors can be discovered with low cost. And it is also not inferior in coverage than other carefully designed testing techniques. One can also obtain reliability estimate using random testing results based on operational profiles. Effectively combining random testing with other testing techniques may yield more powerful and cost-effective testing strategies.

Questions & Answers

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Mmem Reply
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Ravi Reply
what is a computer software
Chinaza Reply
Computer software is programming code executed on a computer processor at either the machine-level or the level of the operating system. ... The physical components of a computer are the hardware, and the digital programs running on the hardware are the software.
what is sofftware
Mohammed Reply
Software, in its most general sense, is a set of instructions or programs instructing a computer to do specific tasks. Software is a generic term used to describe computer programs. Scripts, applications, programs and a set of instructions are all terms often used to describe software.
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shruti Reply
how to activate Microsoft word
Matthew Reply
To activate Microsoft word, please follow these steps below: 1. On windows 8.1 or Windows 10, choose start. 2. Scroll down through your apps and choose Microsoft office- the tile with the Office logo. 3. In the windows that open, choose Activate. 4. Do one of the following:
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Look for it on your Certificate of Authenticity or a card in the packaging. If you cannot find it, contact your reseller. The key uses a combination of 25 letters and numbers and looks this: xxxxx-xxxxx-xxxxx-xxxxx-xxxxx. Enter your key in the space provided. 5. Sign in with your Microsoft account
to activate the Office product that came with your device.
What can we do with cmd
Ibrahim Reply
cmd performs a lot of things that can perfomed in graphical method, generally interacting with files in the computer like deleting, writing, creating cmd can be used for networking purposes... mostly in network configurations, trying to view network setups etc.
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what is software
Igho Reply
is set of instructions (generally referred to as code), that is positioned between you and the device hardware, enable you to use it .
that's what a software can be defined as.
what type of instructions
it may also concern to hardware or not
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what is white box testing
White Box Testing is a software testing method in which the internal structure/ design/ implementation of the item being tested is known to the tester.
What is software life cycle model? Why is it important during the development of a large softwre products
ramsahay Reply
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Source:  OpenStax, Software engineering. OpenStax CNX. Jul 29, 2009 Download for free at http://cnx.org/content/col10790/1.1
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