UNIT – IV TESTING

1. Write about drivers and stubs.

Drivers and stub software need to be developed to test incompatible software.The “driver” is a program that accepts the test data and prints the relevant results.The “stub” is a subprogram that uses the module interfaces and performs the minimal data manipulation if required.

2. What are the approaches of integration testing?

The integration testing can be carried out using two approaches.

1. The non-incremental testing.

2. Incremental testing.

3. What are the advantages and disadvantages of big-bang?

Advantage:

This approach is simple.

Disadvantages:

It is hard to debug.

It is not easy to isolate errors while testing.

In this approach it is not easy to validate test results.

                       

4. What are the benefits of smoke testing?

* Integration risk is minimized.

* The quality of the end-product is improved.

* Error diagnosis and correction are simplified.

* Assessment of program is easy.

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

* The function or performance characteristics are according to the specifications and are accepted.

* The requirement specifications are derived and the deficiency list is created.

6. Distinguish between alpha and beta testing

Alpha and beta testing are the types of acceptance testing.

            Alpha test : The alpha testing is attesting in which the version of complete software is tested by the customer under the supervision of developer. This testing is performed at developer’s site.

            Beta test : The beta testing is a testing in which the version of the software is tested by the customer without the developer being present. This testing is performed at customer’s site.

7. What are the various types of system testing?

1. Recovery testing – is intended to check the system’s ability to recover from failures. 

2. Security testing – verifies that system protection mechanism prevent improper penetration or data alteration.                        

3. Stress testing – Determines breakpoint of a system to establish                                                       maximum service level.  

4. Performance testing – evaluates the run time performance of the                                                                     software, especially real-time software.

8. Define debugging.

Debugging is defined as the process of removal of defect. It occurs as a consequence of successful testing.

9. What are the common approaches in debugging?

Brute force method:

 The memory dumps and run-time tracks are examined and program with write statements is loaded to obtain clues to error causes.

Back tracking method:

The source code is examined by looking backwards from symptom to potential causes of errors.

Cause elimination method:

This method uses binary partitioning to reduce the number of locations where errors can exists

10. What is meant by structural testing?

            In structural testing derivation of test cases is according to program structure. Hence knowledge of the program is used to identify additional test cases.

11. What is meant by regression testing?

                                    Regression testing is used to check for defects propagated to other modules by changes made to existing program. Thus, regression testing is used to reduce the side effects of the changes.      

  

12. What is meant by unit testing?

                                    The unit testing focuses verification effort on the smallest unit of software design, the software component or module.