Table Of Content

PauLlo nSga,r Laahw reayn Vdi ctEolrliias CambriIdngtee rnational ASa nd LeAv el IT Coursebook U CAMBRIDGE V UNIVERSIPRTEYS S CAMBRIDGE UNIVERSITY PRESS University Printing House, Cambridge CB2 BBS, United Kingdom One Liberty Plaza, 20th Floor, New York, NY 10006, USA 477 Williamstown Road, Port Melbourne, VIC 3207, Australia 4843/24, 2nd Floor, Ansari Road, Daryaganj, Delhi -110002, India 79 Anson Road, #06-04/06, Singapore 079906 Cambridge University Press is part of the University of Cambridge. It furthers the University's mission by disseminating knowledge in the pursuit of education, learning and research at the highest international levels of excellence. Information on this title: www.cambridge.org © Cambridge University Press 2016 This publication is in copyright. Subject to statutory exception and to the provisions of relevant collective licensing agreements, no reproduction of any part may take place without the written permission of Cambridge University Press. First published 2016 20 19 18 17 16 15 14 13 12 1110 9 8 7 6 5 4 3 2 1 Printed in Spain by GraphyCems A catalogue record for this publication is available from the British Library ISBN 978-1-107-57724-4 Paperback with CD-ROM Cambridge University Press has no responsibility for the persistence or accuracy of URLs for external or third-party internet websites referred to in this publication, and does not guarantee that any content on such websites is, or will remain, accurate or appropriate. Information regarding prices, travel timetables, and other factual information given in this work is correct at the time of first printing but Cambridge University Press does not guarantee the accuracy of such information thereafter. ·············································································································································································· NOTICE TO TEACHERS IN THE UK It is illegal to reproduce any part of this work in material form (including photocopying and electronic storage) except under the following circumstances: Ii) where you are abiding by a licence granted to your school or institution by the Copyright Licensing Agency; (.ii) where no such licence exists, or where you wish to exceed the terms of a licence, and you have gained the written permission of Cambridge University Press; liii) where you are allowed to reproduce without permission under the provisions of Chapter 3 of the Copyright, Designs and Patents Act 1988, which covers, for example, the reproduction of short passages within certain types of educational anthology and reproduction for the purposes of setting examination questions. ·············································································································································································· All questions and answers provided have been written by the authors. In examinations, the way n1ark'.:ia re awarded may be different. Throughout this book we have used specific brand names to illustrate points in examples. Please note that the examples used do not constitute an exhaustive list, and other brand names are available and should hi=·r :onsidered. Content How to use this book: a guided tour IV Introduct ion VI 1 Data, information, knowledge and processing 1 2 Hardware and software 23 3 Monitoring and control 54 4 E-safety and health and safety 61 5 The digital divide 71 6 Using netwo rks 78 7 Expert systems 95 8 Spreadsheets 102 9 Database and file concepts 136 10 Sound and video editing 175 11 Emerging technologies 188 12 The role and impact of IT in society 200 13 Network s 210 14 Project management 232 15 System life cycle 249 16 Graphics creation 270 17 Animation 280 18 Mail merge 285 19 Programm ing for the web 295 Glossary 308 Answers 313 Acknowledgements 333 Index 334 Learningo bjectives By the end of this chapter, you will be able to: • define the differences between data, information and knowledge • define static and dynamic data • compare static information sources with dynamic information sources • define direct and indirect data sources • understand the advantagesa nd disadvantages of gathering data from direct and indirect data sources • understand how the accuracy,r elevance,a ge, level of detail and completeness of information can affect its quality • describe the coding of data and discussi ts advantages and disadvantages • evaluate the need to encode data and analyse different methods for encoding data • define encryption and describe different methods of encryption • evaluate the need for encryption and how it can be used to protect data • discuss encryption protocols • define validation and analyse a range of validation methods • define verification and analyse verification methods • explain the need for both validation and verification • define proof reading • Learning Objectives - set the scene of each chapter: help with navigation Data: rawn umbersl,e tters.s ymbolss, oundso r images through the book and give a reminder of what's without meaning ( important about each top ic. Information: dataw ith contexta ndm eaning Knowledge: informationt o whichh umane xperienceh as beena pplied TASK Key Terms Look at the BBC website www.bbc.co.uk - identify - clear and straightforward explanations are which data is static and which data 1s dynamic (updates ) provided for the most important words in each automatically). topic .. Task 0 - exercises for the student to test their knowledge and understand ing. DISCUSSION POINT Some people get a little confusedw ith dynamic data becauset hey think it can be any data that changesa t any time. For example, some people think that any website includesd ynamic data. However, if you look at QUESTION http://www.bbc.co.uk/contact the information on this page A company creates websites using style sheets. is mainly static with links to other pages. Although it can be changed, it can only be done by changing the actual 1 Identify one item of data that will be used by the data on the page,w hereas dynamic data changes company. becauset he original source hasc hanged. If you look 2 Describe how this item of data can become at www.bbc.co.uk/click, you will see that most of the information. ) information on this page is sourced from programme / 3 Describe the term knowledge. schedules and programme information which will be stored ( in another database -this makesi t dynamic data becausei t will update when a new programme has been shown. Questions - supporting questions that the student should be Extension activities and Discussion points able to answer to demonstrate understanding at additional lesson activities. this level. . 0 ) Reme1"11ber JavaScript is a programming languaget hat can be used to add interactivity to web pages. Its The confectionary shop could usev arious indirect code can be integrated into a HTMLf ile to: create sources including: buttons, create text boxes, change content etc. • giving out a survey to customers who have It can be integrated with a range of other web based programming languagess uch as PHP. purchaseds weets from the other shops (the price JavaScript is often use with HTMLf orms, where was given to the customer for the purpose of it can validate data or perform actions such as selling the sweet which may have been a different when a button is pressed. date or may have been discounted) looking at till receipts from the shop (the price Remember was printed on the till receipt for the purpose of - these are pieces of vital information to remind providing proof of purchase, not for identifying you about key facts and highlight important points. prices) TIP Examples Take a blank notepad and draw a shape in the bottom - offer students context ualised explanation right-hand corner, then draw the same shape but in a ( of critical points slightly different position on the next page. Repeat this on a number of pages. You can then create a basic animation by flicking through the page of the book. Tip - quick suggestions to help you to understand important concepts. Review Questions Give an example of data (1). 2 Describe the term knowledge (1). A news and sports website includes both static and dynamic data. 3 a Compare static and dynamic data (4). b Identify and describe two factors that affect the quality of information on the website (4). Give an example of coded data related to the news and sports website (1). The website streams news and sports videos. d Explain why the video is compressed when it 1se ncoded (2). e Identify three factors that will affect the size of a video file (1). Identify and describe two factors that affect the file size of images on the website (4). Users can pay for premium services on the website using their credit card. Review Questions 4 a Explain why the website uses https at the beginning of the website address instead - final set of questions of http (4). to test student b Describe symmetric encryption (1). comprehe nsion and to The journalists working for the website encrypt their emails. give any extension tasks. Describe how asymmetric encryption 1su sed with emails (2). when the users subscribe to premium features, they have to choose a password. d Describe how verification can be used when entering the password (1) There is a form on the website that can be used to submit news stories. When data 1se ntered onto the form. it 1s validated. 5 a Describe the purpose of validation (1) b Using an example related to subm1tt111ag news story. 1dent1fya nd descnbe one method of validation (3) This full-colour, illustrated textbook has been written by experienceda uthors specifically for the CambridgeI nternationalA S and A LevelI nformation Technologys yllabus (9626). The qualification replacesA -LevelA pplied ICT.T he new syllabus develops a broad range of IT skills. Throughout the book there are exampleso f IT in practice,t asks for students to complete, discussion points or extensione xercisesto provokef urther thought and discussiona nd questions that will test students' knowledgea nd understanding.W henevera task is presented,w e would encourage students to carry it out before progressingf urther. The syllabusd efinest hree assessmenot bjectives:A O! Recall,s elect and communicate knowledge and understandingo f IT,A 02 Apply knowledge,u nderstanding and skills to produce IT-based solutions and A03 Analyse,e valuate,m ake reasonedj udgements and present conclusions. Each chapter definesa set of learningo bjectivesw hich closely match these assessmento bjectives and a serieso f keyc oncepts( hardwarea nd software, network, the internet, system life cycle, new technologies)r ecurt hroughout the syllabus.T his coursebook has been written to reflect these, in particular in the following chapters:t he impact of information technology (Chapter 12); hardware and software( Chapter2 );n etwork (Chapter1 3);t he internet (Chapters4 and 19); system life cycle (Chapter1 5);n ew technologies( Chapter1 1). It is not necessaryt o work through the book in order from start to finish. Thec ontent of the syllabusi s gearedt owards current practice and practical applications of computersi n everydayl ife. To reflect this, the practical elements of the book are not concerned with, for example,p roviding step-by-step advice on how to use particular software, but rather with helpings tudents to discoverw hat is available and have the confidence to apply their knowledge to different types of software.T his will help to prepare students for the many different aspects of using computers that they will encounter in life, and not just for an exam. Learningo bjectives By the end of this chapter, you will be able to: • define the differences between data, information and knowledge • define static and dynamic data • compare static information sources with dynamic information sources • define direct and indirect data sources • understand the advantages and disadvantages of gathering data from direct and indirect data sources • understand how the accuracy, relevance, age, level of detail and completeness of information can affect its quality • describe the coding of data and discuss its advantages and disadvantages • evaluate the need to encode data and analyse different methods for encoding data • define encryption and describe different methods of encryption • evaluate the need for encryption and how it can be used to protect data • discuss encryption protocols • define validation and analyse a range of validation methods • define verification and analyse verification methods • explain the need for both validation and verification • define proof reading Cambridge International AS and A level IT 1.01 Data,i nformationa nd Information knowledge When data items are given context and meaning , they become information . A person reading the information will then know what it means. Data is given context by identifying what sort of data it is. This Data: raw numbers, letters, symbols, sounds or images still does not make it information but it is a step on the way to without meaning it becoming information as shown in the next example. Information: data with context and meaning Knowledge: information to which human experience has been applied EXAMPLE Data Data Context Comm ent Data is raw numbers, letters, symbols, sounds or images P952BR A product This is a product code with no meaning. code but it is still not know n what it is a product code EXAMPLE for so it is still data. @bbcclick A Twitter This is an address used P952BR handle for Twitter but it is not @bbcclick informat ion unless it is 359 known to be a Twitter handle or used within • 23557.99 Twitter software. It's also not known whose address it is. 359 Price in This is a currency value Pakistani but it is not known what Rupees the price is for, so it is still data. For the data to become information, it needs to be given meaning. Information is useful because it means something. EXAMPLE Figure 1.01- Example of raw data. The data P952BR could have several meanings. It could Data Context Meaning possibly be: P952BR A product A product code for a can code of noodles. a product code a postal I ZIP code @bbcclick A Twitter The Twitter address handle for the BBC's weekly a car registration number. technology show, Click, As it is not known what the data means, it is meaningless. which is worth watching 0 on BBC World News and BBC2 to keep up to date DISCUSSION POINT with technology. When answering a question such as 'Give one item of data', 359 Price in The price of a mobile do not try to explain what the data means because it then Pakistani phone cover. becomes information. Just give the raw numbers, letters, rupees symbols or image. 1.02 Sourceso f data Knowledge Knowledge is basically what a person knows. This is known as their knowledge base. A knowledge base gets larger over time as a person gains experience or Static data: data that does not normally change learning . Knowledge requires a person to understand Dynamic data: data that changesa utomatically without user what information is, based on their experience and intervention knowledge base. Crown Prince Salman was appointed Direct data source: data that is collected for the purpose for Crown Prince of Saudi Arabia on 18 June 2012. This is which it will be used information. Knowing that he had been Crown Prince Indirect data source: data that was collected for a different for 2 years on l August 2014 is knowledge. Knowledge purpose (secondarys ource) allows data to be interpreted . In computing terms, knowledge is also what a machine knows through the use of a knowledge base consisting of rules and facts, often found in knowledge-based systems, modell ing and Static data simulation software. EXAMPLE '-~.t ,..,;_ B .. Information Knowledge lOOkm/h is the speed Travelling at 120km/h on , m~ limit on expressways in expressways in Pakistan Pakistan. is illegal. A red traffic light means a car should stop. Figure 1.03 -A good example of static data. Static means 'still'. It is data that does not normally change. Static data is either fixed or has to be changed manually by editing a document. Figure 1.02 -A red traffic light. EXAMPLE 359 Pakistani rupees The price of a mobile title of a web page is the price of a mobile phone cover is more phone cover. expensive than a cup of , magazines coffee. • CD-ROMs , column headings for a football league table (e.g. P, W, D, L, F, A, GD) QUESTIONS • instructions on a data entry screen. A company creates websites using style sheets. 1 Identify one item of data that will be used by the company. Dynamic data 2 Describeh ow this item of data can become information. Dynamic means 'moving' It is data that updates as a roc,ult 3 Describe the term knowledge. of the source data changing. Dynamic data is upclatccl automa tically without use, intervention.