1. Black Box Testing or Behavioral
Testing
Saranya.V
AP/CSE,
Sri Vidya College of Engineering & Technology,
Virudhunagar

2. • Only input & output functionality are visible.
• Inputs are given and outputs are compared
against specification.
Features:
 Correct outputs from inputs properly.
 Test cases are designed from user requirements.
 Test planning can begin early in the software
process.
 Looking at the program from an external point
of view.

4. Black Box Testing
Inputs causing
Input Test Data I anomalous
behavior
System
Outputs which
output Test Results O reveal the
presence of
defects

5. Black Box Testing is a “Expert” in
Finding
• Incorrect or missing functions.
• Interface errors
• Behavior or performance errors.
• Initialization and termination errors.
• Errors in data structures
• External database errors.

6. Graph Based Testing Methods
• First step in Black Box Testing to understand the
objects
• Used to connect the objects.
• Next step is to define a series of tests that verify all
the objects.
“To accomplish these steps, the software engineer
begins by creating”
• Graph: collection of nodes that represent objects.
• Links: Relationship between objects.
• Node Weights: Properties of nodes
• Link Weights: Characteristics of a link.

7. Sample Graph Notation
Directed Link
Object 1 Object 2
Object 3
•Nodes are represented as circles.
•Links between nodes are categorized as:
•Directed Link (one direction)
•Bidirectional or Undirected or Symmetric Link: both directions.
•Parceled links: different relationships established between nodes.

8. 1. Equivalence Partitioning
• One of the black box testing method that
divides the input domain of a program into
classes
• Define a test case that uncovers classes of
errors.
• Equivalence class represents a set of valid or
invalid states for input conditions.

9. 2. Boundary Value Analysis (BVA)
• Errors tend to occur at the boundaries of the input
domain rather than in center.
• So we need boundary value analysis (testing
technique)
• BVA derived test cases from the output domain.

10. 3. Comparison Testing
• If the output from the each version is same,
assume all implementations are correct.
• If the output is different, each of the
applications is investigated to determine if a
defect in one or more versions is responsible
for the difference.
• We have to provide same input and check the
output.

11. 4. Orthogonal Array Testing
• Used to finding errors associated with region
faults.
• number of inputs to the system is relatively
small, but too large to allow for exhaustive
testing of every possible input to
the systems.
• It provides good test coverage with test
cases.

12. 5. Syntax Driven Testing
• Very good methodology for compliers and
parsers.
• Use BNF notation.
• Described by grammar.
• Grammar for simple arithmetic:
(exp)::=(exp)+(term)|(exp)-(term)|(term)
(term)::=(term)*(factor)|(term)-(factor)|(factor)
(factor)::=(identifier)|(<expression>)
(id)::=|a|b|c|d|e………|z

13. 6. Decision Table-Based Testing
• Ex: Toy Text Editor
• Here n=4;
• 1. Copy
• 2. Paste
• 3. Underline
• 4. Boldface

14. Ex:2 Liquid Level
• Sensor 1 : used to
check upper level
• Sensor 2: used to
Sensor 1 check Lower level
• Sensor 1 is active :
open output valve
• Sensor 2 is active
Sensor 2 open input valve.

15. 7. Cause and Effect Graphs in
Functional Testing
• Represents relationship between input and
output
• Input  cause
• Output  effect.
Ex: ATM Banking Transaction System

16. Causes:
C1: Command is credit
C2: Command is Debit
C3: Account Number is valid.
C4: Transaction amount is Valid.
Effects:
E1: Print “Invalid command”
E2: Print “invalid account number”
E3: Print “debit amount not valid”
E4: debit account
E5: credit account.

17. Types processing modes
• And  effect occurs of all the inputs are true.
• Or  Effect occurs if at least one input is true
• Negation : effect occurs if input are false.

18. C2
and
E3
C3
C4 Used to reduce the test case count
C1 C2 C3 C4
Don’t care
condition True false