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Video Title: Black Box Testing
Description: Black Box Testing
Watch more Videos at https://www.tutorialspoint.com/videotutorials/index.htm
Lecture By: Mr. Arnab Chakraborty, Tutorials Point India Private Limited
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In this session, we are discussing black
box testing.

In case of black box
testing, the tester will

not have any access
over the software coding.

So, as a result of that,
the tester cannot view

the code, cannot access
the code of the program.

So, there is no question of changing the
code, only the tester can access the

inputs and the respective outputs obtained
after being processed.

So, that is the basic theme behind this
black box testing.

So, it actually tests the behavior of the
system.

So, it is carried out
to test functionality of

the program and also
called behavioral testing.

The tester in this case has a set of input
values and respective desired results.

And on providing input, if the output
matches with the desired results,

the program is tested ok.

And otherwise, it will be treated as it is
having some problems.

So, here you can see that this is our
respective software.

We have made it that one shaded only to
show you, only to visualize that this

particular coding, whatever
the constructs we have

used, what is the software
design we have used.

It has been kept hidden from the tester.

So, tester can put some inputs, it will get
processed and the outputs will be obtained.

And this particular output which will be
obtained from the software will be matched

with the desired output list.

And if they are matching, then the
software is ok.

Otherwise, the software is having some
problems and problematic errors.

So, in this testing
method, the design and the

structure of the code are
not known to the tester.

And testing engineers and the end users
conduct this test on the software.

So, testing users and also the
end users who are not having

the access over the code can
conduct such testing process.

So, black box testing techniques.

So, first one we are going to discuss that
is the equivalent class.

The input is divided into similar classes.

And if one element of a class passes the
test, it is assumed that all the class,

the full class is passed.

So, that is here the inputs will be
divided into multiple different classes.

Now, one class representative input,
if it passes the test, that means all the

values in that class have passed.

Next one is our boundary values.

The input is divided into higher and the
lower end values.

So, if this values pass the test,
it is assumed that all the values in

between falling may also pass too.

So, that means here we
are considering the highest

value and the lowest value
of that particular input set.

And if this boundary values are passing,
passing means what means the output what

will be generated by the software is
matching with the desired output.

That means, the quality is ok.

So, the testing has been done
successfully.

Then we can assume that
all the values which will be

falling in between this higher
and the lower limit values.

So, for them also the testing will be ok
for us.

Next one is our cause and effect graphing.

In both previous methods, only one input
value at a time is getting tested.

So, cause means input, effect means output
is a testing technique where combinations

of input values are tested in a systematic
way.

So, here combination
of certain input values will

be given and according
to the system will be tested.

But in the earlier cases, we are considering
that one of the values from the class.

So, values which are the lower and upper
limits of the input values.

So, they are only getting tested not the
all values.

But here you can see we
are having the combination of

multiple input values and the
system will be tested on them.

So, the next one is our pair wise testing.

The behavior of software depends on
multiple parameters.

So, in pair wise testing,
the multiple parameters

are tested pair wise
for their different values.

So, a particular module may be having
multiple inputs.

So, in case of pair wise testing,
we shall do the multiple pairs.

Pair wise inputs will be given to the
software and the outputs will be verified.

Next one is our state based testing.

The system changes state on provision of
input.

So, these systems are tested based on the
states and the input.

We know that whenever inputs will be
given, we are having some conditions,

we are having some branching instructions
will be there.

So, the condition may be true,
the condition may be false.

When the condition will be true,
then system will be going to a separate

different state.

When the condition will be false,
then also the system will be going for

different So, as a result
of that, depending upon the

inputs, the state of the
system is getting changed.

So, now what will happen in case of
state-based testing?

We shall do the testing on this particular
system at its different states.

So, in this way, we have discussed what is
the black box testing, what are the

different merits and demerits,
and what are the different types of this

kind of testing can be carried out.

Thanks for watching this video.