Lesson 1: Data Hierarchy, Variables And Constants

Question 1

What is the smallest unit in a computer?

Answer 1

Bits

Full name ‘Binary Digits’; represents 1’s and 0’s.

Question 2

What is a character in terms of data hierarchy?

Answer 2

The smallest unit of data, made up of bits.

Question 3

What is a field in data hierarchy?

Answer 3

A number of characters or a name, also known as a data item.

Question 4

What is a record?

Answer 4

A group of related fields, stored sequentially.

Question 5

Define a file in data hierarchy.

Answer 5

A collection of related records, organised and stored in a specific way.

Question 6

What is the structure of a table?

Answer 6

Consists of rows and columns.

Question 7

What is a database?

Answer 7

A group of related files or tables, organised based on processing methods.

Question 8

What is a data warehouse?

Answer 8

The largest structure for collecting and storing data for processing, analysis, and reporting.

Question 9

What is unprocessed data considered?

Answer 9

Meaningless.

Question 10

What is processed data called?

Answer 10

Information.

Question 11

What is output in the context of data?

Answer 11

Processed data.

Question 12

What are variables used for?

Answer 12

To store data that can change.

Question 13

What must every variable have?

Answer 13

A descriptive name.

Question 14

What is a key rule for naming variables?

Answer 14

The name must be unique.

Question 15

What are the types of variables?

Answer 15

• String
• Integer
• Real number
• Boolean
• Character

Question 16

What does the value of a variable do during program execution?

Answer 16

It can change.

Question 17

What are constants?

Answer 17

Similar to variables, but have a fixed value that cannot change.

Question 18

When are constants used?

Answer 18

When a value will never vary during program execution.

Question 19

Give examples of constants.

Answer 19

• 24 hours in a day
• The value of Pi (3.14159)
• A specific message

Question 20

How do variables and constants function in expressions?

Answer 20

They are used in expressions and assignment statements.

Question 21

What does an assignment statement do?

Answer 21

Gives a value to a variable.

Question 22

What are the three cases for assignment?

Answer 22

• Initialise, set
• Assign a value as a result of processing
• Save, store

Question 23

What is a data model?

Answer 23

A communication tool that facilitates interaction between developers and end-users

Question 24

What are the basic building blocks of data models?

Answer 24

Entities, attributes, relationships, and constraints

Question 25

Define an entity.

Answer 25

An object or thing that an organisation wants to collect and store

Question 26

Give an example of an entity.

Answer 26

Books in a library

Question 27

Can an entity be abstract? True or False?

Answer 27

True

Question 28

What are attributes in the context of data models?

Answer 28

Characteristics or descriptions of an entity

Question 29

List three examples of attributes for the entity 'book'.

Answer 29

* ISBN number * Book title * Number of pages

Question 30

What is the relationship between an entity and its attributes?

Answer 30

Attributes describe the features of an entity

Question 31

Fill in the blank: The information captured about a person when obtaining library membership is referred to as _______.

Answer 31

[attributes]

Question 32

What does the information about a person in the library system represent?

Answer 32

Attributes of the entity (the person)