SOFTWARE TESTING 2nd Chapter

Q 1. Explain following terms with the help of example of software engineering:

i) Data Objects

ii) Data Attributes

iii) Relationships

iv) Cardinality and Modality

Ans:

1) Data objects

A data object‖ is a representation of almost any composite information that must be understood

by software. By composite information, something that has a number of different properties or

attributes.

Example:

Width (a single value) would not be a valid data object, but dimensions (incorporating height,

width and depth) could be defined as an object.

2) Attributes

Attributes define the properties of a data object and take one of three different characteristics.

They can be used to:

1. Name an instance of the data objects,

2. Describe the instance,

3. Make reference to another instance in another table.

Example: attributes must be defined as identifier. Referring to data object car, a reasonable

identifier or attribute might be the ID No, Color.

                       

3) Relationships

Data object are connected to one another in variety of different ways. This links or connection of

data objects or entities with each other is called as relationship.

Example:

A connection is established between person and car , because the two objects are related.

1.      A person owns a car

2.      A person purchase a car

3.      A person sells a car

4.      Person cleans a car

The relationship owns, purchase, sells, and cleans‖ define the relevant connections

between person and car.

4) Cardinality

Cardinality is the specification of the number of occurrences of one object that can be related to

the number of occurrences of another object. Cardinality is usually expressed as simply one or

many.

Example: One object can relate to only one other object (a 1:1 relationship);

One object can relate to many other objects (a 1: N relationship);

Some number of occurrences of an object can relate to some other number of occurrences of

another object (an M: N relationship);