UNIT 4

1.What are the characteristics of good tester?

 All tests should be traceable to customer requirements.
 Tests should be planned long before testing begins.
 The Pareto principle applies to software testing.
2.Define software testing?
 Software testing is a critical element of software quality assurance and
represents the ultimate review of specification, design, and coding.
3. What are the objectives of testing?
 Testing is a process of executing a program with the intend of finding
an error.
 A good test case is one that has high probability of finding an
undiscovered error.
 A successful test is one that uncovers as any undiscovered error.
4 What is integration testing? and What are the approaches of integration testing ?
 In this testing the individual software modules are combined and
tested as a group.
 It occurs after unit testing & before system testing.
1. The non-incremental testing.
2. Incremental testing.
5 What is regression testing?
 It tends to verify the software application after a change has been
made.
 It seeks to uncover software errors by partially retesting a modified
program.
6.Distinguish between stress and load testing
 Stress testing is subjecting a system to an unreasonable load while
denying it the resources (e.g., RAM, disc, mips, interrupts, etc.)
needed to process that load.
 Load testing is subjecting a system to a statistically representative
(usually) load.
 The two main reasons for using such loads is in support of software
reliability testing and in performance testing.
 The term "load testing" by itself is too vague and imprecise to warrant
use.
7 Define black box testing?
 A black-box tests are used to demonstrate that software functions are
operational, that input is properly accepted and output is correctly
produced, and that the integrity of external information.
8 What is boundary condition testing?
 It is tested using boundary value analysis.
9 How is software testing results related to the reliability of software?
 Applying fault avoidance, fault tolerance and fault detection for the
project helps to achieve reliability of software.
10 .What is big-bang approach?
 Big bang approach talks about testing as the last phase of
development.
 All the defects are found in the last phase and cost of rework can be
huge
11.Why does software fail after it has passed from acceptance testing?
 Each acceptance test represents some expected result from the system.
  Customers are responsible for verifying the correctness of the
acceptance tests and reviewing test scores to decide which failed tests
are of highest priority.
 Acceptance tests are also used as regression tests prior to a production
release. A user story is not considered complete until it has passed its
acceptance tests. This means that new acceptance tests must be
created for each iteration or the development team will report zero
progress.
12 What are the objectives of testing?
 Testing is a process of executing a program with the intend of finding an
error.
 A good test case is one that has high probability of finding an
undiscovered error.
 A successful test is one that uncovers as an-yet undiscovered error.
13.What are the testing principles the software engineer must apply while
performing the software testing?
 All tests should be traceable to customer requirements.
 Tests should be planned long before testing begins. iii. The pareto
principle can be applied to software testing-80% of all errors
uncovered during testing will likely be traceable to 20% of all
program modules. iv. Testing should begin “in the small” and
progress toward testing “in the large”. v. Exhaustive testing is not
possible. vi. To be most effective, an independent third party should
conduct testing
14.What are the two levels of testing?
 Component testing Individual components are tested. Tests are derived
from developer‟s experience. ii. System Testing The group of
 components are integrated to create a system or subsystem is
done.These tests are based on the system specification.
15 What are the various testing activities?
iii. Test planning iv.Test case design v. Test execution vi. Data collection
vii. Effective evaluation
16 What is equivalence partitioning?
 Equivalence partitioning is a black box technique that divides the input
domain into classes of data. From this data test cases can be derived.
Equivalence class represents a set of valid or invalid states for input
conditions.
17 What methods are used for breaking very long expression and statements?
Refactoring is done to break long expression and ststements. 16 What are the
various testing strategies for conventional software? i. Unit testing ii. Integration
testing. iii. Validation testing. iv. System testing.

18 How can refactoring be made more effective

 Refactoring improves nonfunctional attributes of the software.
Advantages include improved code readability and reduced
complexity; these can improve source-codemaintainability and create
a more expressive internal architecture or object model to improve
extensibility4
19 How will you test a simple loop
A simple loop is tested in the following way: Skip the entire loop. Make 1 pass
through the loop. Make 2 passes through the loop. Make x passes through the
loop where x

20.What are the conditions exists after performing validation testing?

 After performing the validation testing there exists two conditions.
The function or performance characteristics are according to the
specifications and are accepted.
 The requirement specifications are derived and the deficiency list is
created. The deficiencies then can be resolved by establishing the
proper communication with the customer.