software testing

Question 1

what is test data

Answer 1

inputs which have been devised to test the system

Question 2

test cases

Answer 2

input and predicted output

Question 3

what is black box testing

Answer 3

programs test cases are based on the system specification. Test planning can begin early

Question 4

what is equivalence partitioning

Answer 4

classes for input dat and output. Generally choose test cases at the boundary of the sets in the classes coz these are more likly erroneous behaviour and choosing random values.

Question 5

what is another name for structural testing

Answer 5

white box testing

Question 6

what does structural testing entail?

Answer 6

derivation of test cases according to program structure. Objective is to exercise all program statements(not all program combinations).

Question 7

difference between black and white box testing

Answer 7

Programming knowledge and implementation knowledge is needed in white box

Question 8

what is path testing

Answer 8

ensure that the set of test cases is such that each path through the program is executed atleast once.

Question 9

what is program flow graphs

Answer 9

describes the program control flow. each branch is shown as a seperate path and loops are shown by arrows looping back to the loop condition node. Used for computing cyclomatic complexity

Question 10

what is the cyclomatic complexity

Answer 10

number of edges - number of nodes + 2 in the program flow graph

Question 11

what does the cyclomatic complexity involve

Answer 11

number of tests to test all control statements equals the cyclomatic complexity. Equals the the number of conditions of a program +1.

Question 12

Disadvantage of cyclomatic complexity

Answer 12

all combinations of paths are not executed.

Question 13

apart from the cyclomatic complexity, what else can be used to check that paths have been executed?

Answer 13

a dynamic program analyser

Question 14

is integration testing black or white box

Answer 14

black- tests complete or subsystems of ingrated components.

Question 15

what is the problem of integration error

Answer 15

localising errors

Question 16

what idea does incremental integration testing use

Answer 16

regression testing- future tests also test previous cases again.

Question 17

How can we ensure that the addition of a new module does not break the previous test case?

Answer 17

use a test harness-program written to automatically generate test data and record their test results

Question 18

Name two approaches to integration testing and which approach does it use?

Answer 18

Top-down (high level system and integrate from top down replacing individual components by stubs).
Bottom-up (integration individual components in level until complete system).
Most integration use a combo of both

Question 19

which types of system is bottom up testing appropriate for?

Answer 19

object-orientated systems - have a neat decomposition into classes and methods- makes testing easy.
Real-time systems- can identify slow code
systems with strict performance requirements - can measure the performace early on

Question 20

benefits of top down

Answer 20

better at discovering errors in the system architecture

allows a limited demonstration at an early state

Question 21

problem with both bottom up and top down

Answer 21

test observation - extra code may be required to observe tests.

Question 22

what is a procedural interface

Answer 22

sub system encapsulate a set of procedures to be called by other sub systems

Question 23

what are some interface errors

Answer 23

interface misuse
interface misunderstanding
timing errors(out of data info is accessed)

Question 24

what is stress testing

Answer 24

exercise the sstem beyog its max design load. checks for unacceptable loss of data

Question 25

why can be object class testing be difficult

Answer 25

because of inheritance - as the information being tested is not localised

Question 26

what is cluster testing

Answer 26

integrating and testing clusers of cooperating objects.

Question 27

what are some approaches to cluster testing

Answer 27

use case or scenario testing (based on user interaction)
thread testing
object interaction testing

Question 28

explain scenario based testing

Answer 28

supplement scenarios from use cases with interaction diagrams.