GCSE Information Technology
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GCSE Information Technology
Contents
Chapter 0 - Introduction
0.1 About this book
0.2 Applications Used
0.3 Questions/Answers
0.4 Optional Research
0.5 Bookmarks
Chapter 1 - Introduction to Information Technology
1.1 Definitions for this Chapter
1.2 Information Technology - Defined
1.3 Digital vs. Analogue
Chapter 2 - Information and Data
2.1 Definitions for this Chapter
2.2 Information and Data
2.3 Data Types
2.4 Character Sets
2.5 Coding Data
2.6 Processing Information
Chapter 3 - Computers and Types of Processing
3.1 Definitions for this Chapter
3.2 What makes up a Computer?
3.3 Types of Computer
3.4 Types of Processing
Chapter 4 - Capturing and Inputting Data
4.1 Definitions for this Chapter
4.2 Data Capture
4.3 Inputting Data
Chapter 5 - User Interfaces
5.1 Definitions for this Chapter
5.2 User Interfaces
Chapter 6 - Outputting Data
6.1 Definitions for this Chapter
6.2 What is an output device?
6.3 Monitors
6.4 Printers
6.5 Other Output Methods
Chapter 7 - Storing Data
7.1 Definitions for this Chapter
7.2 Storage
7.3 How a disc works
7.4 Accessing Storage
7.5 Files
7.6 Security of files
Chapter 8 - Applications Software
8.1 Definitions for this Chapter
8.2 Software, Programs and Applications Software
8.3 Types of Application Package
8.4 Deciding which package to buy
8.5 Some typical packages
8.6 Communication between packages
Chapter 9 -Word Processing
9.1 Definitions for this Chapter
9.2 Introduction to Word Processing
9.3 Margins
9.4 Indents
9.5 Tabs
9.6 Blocks of text
Chapter 10 - Databases
10.1 Definitions for this Chapter
10.2 What is a database?
10.3 Setting up a database
10.4 Using a database
Chapter 11 - Spreadsheets
11.1 Definitions for this Chapter
11.2 Models
11.3 Spreadsheets
Chapter 12 - Graphics
12.1 Definitions for this Chapter
12.2 Graphics
Chapter 13 - Communications and Networks
13.1 Definitions for this Chapter
13.1 Introduction to Communications and Networks
13.3 Types of Network
Chapter 14 - Control Systems
14.1 Definitions for this Chapter
14.2 What is a Control System?
14.3 Communicating with the devices
14.4 What can the computer control?
14.5 Feedback
14.6 Turtles and LOGO
Chapter 15 - Developing Systems
15.1 Definitions for this Chapter
15.2 The System Life Cycle
Chapter 16 - Documentation
16.1 Definitions for this Chapter
16.2 Types of documentation
16.3 Flowcharts
Chapter 17 - The impact of IT
17.1 Definitions for this Chapter
17.2 A brief History
17.3 The effect IT have had on our lives
Chapter 18 - Your Coursework Project
18.1 Introduction
18.2 What shall I do for my coursework?
18.3 How do I do my coursework?
Chapter 99 - Answers to Questions
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GCSE Information Technology
Chapter 0 - Introduction
Chapter 0 - Introduction
0.1 About this book
This book is for Information Technology GCSE Key Stage 4. It is known as a short course. This means, in order to get a GCSE certificate the students have to continue with their IT studies to convert the course into a GCSE for Information Systems. Alternatively, they can combine Information Technology with another subject to give a combined GCSE.
This book covers the syllabuses for all examination boards.
0.2 Applications Used
This book was written using Microsoft Office (Word 6, Excel 5 and Access 2). The screen shots are taken from these packages.
However, the book does not assume the student is using any particular package.
The author would like to thank Microsoft for permission to use the screen shots.
0.3 Questions/Answers
Most sections have questions at the end. These check the students understanding of the material just presented. The teacher can obviously choose which questions to use and can incorporate their own.
Suggested answers to the questions are given in Chapter 99. For obvious reasons, the students should not be given access to this chapter.
0.4 Optional Research
At the end of each chapter there is normally an ‘optional research’ section. This material is not examinable but could be used as exercises for students who show a strong interest in IT.
0.5 Bookmarks
In order to make this book as easy to use as possible ‘bookmarks’ have been placed at the start of each chapter. If you use Word to read this book you can use the Edit/Bookmark menu to display a dialogue box; like this:
You can now select the Chapter you want to go to and Click on Go To.
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GCSE Information Technology
Chapter 1 - Introduction to Information Technology
Chapter 1 - Introduction to Information Technology
1.1 Definitions for this Chapter
Information Technology (IT) : Describes the equipment and software used to process
information. It is not only used when talking about computers.
Digital : Describes something which can be in a known numbers of states.
Analogue : Describes something which is continuously variable - for example sound or
the level of a river.
1.2 Information Technology - Defined
The term Information Technology (IT) is used to describe the equipment we use to process information and the software we use to carry out those processes.
A calculator is an example of IT. It is a piece of technology that processes numbers that we enter into it.
A telephone is another example. It processes the sounds that we make so that they can be understood by somebody, perhaps, on the other side of the world.
Of course, a computer is another (and perhaps the most common) example of IT. It is also probably the most versatile example of IT as it can be used as a Word Processor, a Database, a Spreadsheet; in fact a computers uses are also unlimited.
There are generally considered to be five main areas of IT; these being:
- Handling Information : This includes sorting data, searching for data and carrying out analysis on data. This is typically done by a database program but many other types of program also carry out these operations.
- Communicating Data : Using IT it is possible to send data around the world by telephone lines, radio waves - even microwaves. Before this technology was available it could be weeks or even months, before you could get access to information on the other side of the world.
- Measuring and Control : This area of IT allows a machine to interact with the outside world and act on the input it receives. For example, a car production line is able to sense when a car body is in a certain position and weld together the relevant parts of the car.
- Presenting Information : IT is useless unless the output of the various processes is presented in a form we understand. Word Processors, Desk Top Publishers - even the television - takes raw data and presents it in a format we can understand and find attractive.
- Modelling the Real World : Using simulations we can see what happens if we do something without having to do it for real. The government, for example, may run a simulation to see what would happen if they were to raise interest rates. Spreadsheet applications are often used to build models of, say, a company’s accounts.
Q.1.2 Questions
Q.1.2.1 Give three examples of IT, that you use every day.
Q.1.2.2 Looking at the five main areas of IT, above, give one example of each area that you use in everyday life
1.3 Digital vs. Analogue
In IT you will often hear the term digital and occasionally the term analogue. But what do they mean?
Digital : If something can be in one or more specific states it is said to be digital. For example, a light switch is either on or off - it cannot be in between. This could be described as a digital device. Another example are the coins in your pocket. They can only take certain values. A single coin cannot represent a value of, say, seven pence.
Analogue : If something varies continuously it is said to be an analogue device. For example, a river is analogue as its level is constantly changing. Another example is a television signal. The picture is represented by a constantly varying signal which eventually arrives at your TV set.
Q.1.3 Questions
Q.1.3.1Would you consider the following digital or analogue?
i The music coming from a speaker
ii The price of postage stamps
iii Whether a bank account is in credit or debit (in the black or in the red)?
iv The different combinations of colours a traffic light can have
Q.1.3.2 Give an example of something which is digital and something which is analogue?
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GCSE Information Technology
Chapter 2 - Information and data
Chapter 2 - Information and Data
2.1 Definitions for this Chapter
Information : Facts and knowledge that has meaning.
Data : Information that is held in a form that can be processed.
Data Type : Describes how a piece of data can be used and stored.
Data Processing Cycle : The sequence of events that is used to process information.
2.2 Information and Data
Information and data are fundamental to IT. Everything we consider in this book is somehow related to Information and Data.
But what is the difference between the two terms? As can be seen in the definitions (above), information has some sort of meaning whereas data is information in a form in which it can be processed.
Here are some examples:
Information
- A telephone directory.
- A company report.
- A class register showing who has attended each day.
- A letter produced on a word processor.
Data
- The names which are in a telephone directory.
- A company report stored in a word processor document.
- A list of students in a class.
Notice how the information has meaning. By comparison, the data does not have meaning; at least not until we do something to convert it (process it).
For example, a company report stored on your computer does not have meaning. But if we apply a process to it (in the form of a Word Processor) we can print something that does have meaning.
Sometimes it is not always easy to decide if something is information or data.
A list of students in a class could be information if all you wanted to know was who was in the class. But if you wanted to know who has attended each day the data would need to be processed so that it is a class register.
In some cases data and information is different depending on who is looking at it.
If you cannot read French, a book written in that language is just data but it is information to somebody who understands the language as they can make sense of the words.
Q.2.2 Questions
Q.2.2.1 Give two examples of information?
Q.2.2.2 Give two examples of data?
Q.2.2.3 Whether something is information or data sometimes depends on who is looking at it. Give two examples where this could be the case and say who would regard it as information and who would regard it as data?
2.3 Data Types
Adata typedescribes how data is processed and stored.
The number 3.67 is a numeric data type. Being numeric we can perform calculations on it. We could, for example, add 34.78 to it.
The characters ‘computer’ is a string data type. It makes no sense to add 34.78 to the word computer.
As well as dictating the operations that can be performed on the data, the data type also defines how the data is stored. Numeric values are normally stored in a special format that makes calculations easier for a computer to do.
2.3.1 Examples of Data Types
These are some of the common data types. There are others and, sometimes, you are allowed to define your own.
CharacterA single letter, punctuation character or number. For example ‘a’, ‘!’ and ‘3’. There are also special characters which cannot be printed or seen on the screen. If you are printing a report and the printer starts a new page a ‘Form Feed’ control character has been sent to the printer. Although you cannot see a ‘Form Feed’ on the screen it is still a character.
There are also other characters which are simple graphics. Using these you can get special effects such as drawing a border around a screen.
StringA series of characters. For example, “This is a string”. A string that contains both letters and numbers is sometimes referred to as an alphanumeric data type
NumericA number. For example 12.45, -678.98, +5.89234
IntegerA whole number. For example 12, 19862, 100861
Q.2.3 Questions
Q.2.3.1 Look at the following data and say which data type best describes it
i12
iia
iiiaa
iv-34.98
vA telephone number
viYour age
viiYour Christian Name
2.4 Character Sets
A character set is a complete set of characters used for a specific purpose.
The character set for a computer typically consists of 256 characters (called the ASCII (pronounced askey) character set). This contains all the characters that your computer uses. It includes all the numbers, letters and punctuation symbols. It also includes many other characters; some of which are not printable (for example a form feed character).
Q.2.4 Questions
Q.2.4.1 What characters do you think make up the character set of the English language?
Q.2.4.2 What is the character set for all the non-vowel characters in the English alphabet.
2.5 Coding Data
You already use codes in your everyday life without even realising it. A date such as 21/07/61 is a code for 21st July 1961. A time given as 21:15 is a code for a quarter past nine in the evening. Your bank account number is a code that represents your account within the bank.
Computers also use codes to store data. Some of the reasons for this are as follows.
- It uses less space. An international company might use a two character code to represent a country rather than the full name of the country; say ‘UK’ instead of ‘United Kingdom’.
- It makes the data easier to handle. In the above example manipulating “UK” is easier (and faster) than having to manipulate “United Kingdom”
- It is more consistent. Users are less likely to make a mistake entering ‘UK’ rather than ‘Unitex Kingdom’ (see what I mean?)
- The computer is able to perform validation easier as there are only a certain number of codes. By contrast you might enter ‘United Kingdom’, ‘Britain’ or ‘England’ to represent the same country.
Of course, there are problems with using codes. Probably the main one is the fact that the user has to be familiar with the codes being used or else keep looking them up. However this is not so much of a problem these days as the computer themselves can assist in the process and make the codes being used almost invisible to the users.
Q.2.5 Questions
Q.2.5.1 Give three examples of where you use codes in your daily life, almost without realising it.
Q.2.5.2 If you were asked to introduce a coding scheme for the Premier Division Football teams how would you do it? As well as devising a coding scheme what else would you need to think about?
2.6 Processing Information
Computers are all about processing information (normally called Information Processing). There is a typical sequence of events in processing information called the data processing cycle. The normal sequence of events is;
- Data Collection is the collection of data from whichever source you are using. It might be a survey conducted on the High Street, figures from company accounts or the names of people who will be attending school next term.
- Data Input is inputting the data into the computer. How and where you input the data will depend on the type of data, the equipment you have available and the type of software you are using.
As the data is input it is checked (validated) and stored on the computer in a suitable format for later processing. The concept of a data type (covered above) is important in the input phase of the data processing cycle. - Processing is converting the data from one form to another. Maybe, a set of company accounts for a High Street retailer needs to be sorted into some sort of order. Maybe you want to use the data you have inputted to produce summary information by adding up all the figures for each store to give one total.
- Output is concerned with producing output from the data in a form acceptable to the person processing the data. Maybe the output will be a set of company accounts ready to submit to the tax office. Maybe, for a supermarket, it will be bar code labels that they will put on the shelves, together with a price for each item.
This cycle continues so that after you have produced the output you will go back to the beginning and collect more input. For example, a supermarket will receive deliveries and sell goods. This data has to be collected and input to the computer on a daily basis.
Q.2.6 Questions
Q.2.6.1 Consider a class register. Identify what happens to it during the various phases of the data processing life cycle.
R.2 Optional Further Research
R.2.1 The ASCII character set is the most commonly used character set. What does ASCII stand for?
EBCIDIC is another common character set. What does EBCIDIC stand for?
Get a copy of the ASCII character set and find out how many control characters there are.
R.2.2 What code is used to uniquely identify a book? What does each part of the code represent?
R.2.3 A light switch could be described as a binary device. What is meant by binary and why is it important with regards to computers?
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GCSE Information Technology
Chapter 3 - Computers and Types of Processing
Chapter 3 - Computers and Types of Processing
3.1 Definitions for this Chapter
Computer : A device that processes data that has had input put into it. The processing
is done via a series of fixed instructions, usually called a program.
Central Processing Unit : The main part of the computer which controls all the other
parts of the computer.
RAM : Random Access Memory. Temporary storage in a computer that holds
programs and data.
ROM : Read Only Memory. Similar to RAM but you cannot write to the memory.
Normally stores programs which never change.
Discs : Used for permanent storage of data. There are three types of disc; Hard Discs,
Floppy Discs and CD-ROM’s.
Hardware : The physical pieces of equipment that make up a computer.
Software : The instructions that tell the computer what to do.
Personal Computer (PC) : A computer used by one person at a time.
Mainframe Computer : Large computers that can look after many jobs and users at
the same time.
Minicomputer : A computer that is more powerful than a PC but not as powerful as a
mainframe. Usually runs many jobs and has many people attached to it at the same
time.
Stand-Alone system : A computer used by one person at a time.
Multi-User system : A computer used by many people at the same time.
Real Time Processing : A computer that reacts to input as soon as it receives it.
Interactive Processing : You communicate with the computer and it responds; like a