Theory Booklet

AS ICT (9626)

September 2016

1.1 Data, information and knowledge ............................................................................................................................................................... ........4 1.2 Sources of data ......................................................................................................................................................................... ...................................... 4 1.3 Quality of information ........................................................................................................................................................... ................................... 10 1.4 Coding, encoding and encrypting data ............................................................................................................................................ ............ 11 1.5 Checking the accuracy of data ................................................................................................................................................................ ......... 24

2.1 Hardware ........................................................................................................................................................... ................................................................. 26 2.2 System, application and user interface software .................................................................................................................................. 33 2.3 Utility software .............................................................................................................................................. ................................................................. 50 2.4 Custom written software and off-the-shelf software ........................................................................................................................... 52 2.5 Compiler and interpreter ..................................................................................................................................................... ................................... 53

6.1 Network types ................................................................................................................................................ ................................................................. 69 6.2 Video and web conferencing ............................................................................................................................................ ................................... 78

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1.1 Data, information and knowledge ............................................................................................................................................................... ........4 1.2 Sources of data ......................................................................................................................................................................... ...................................... 4 1.3 Quality of information ........................................................................................................................................................... ................................... 10 1.4 Coding, encoding and encrypting data ............................................................................................................................................ ............ 11 1.5 Checking the accuracy of data ................................................................................................................................................................ ......... 24

2.1 Hardware ........................................................................................................................................................... ................................................................. 26 2.2 System, application and user interface software .................................................................................................................................. 33 2.3 Utility software .............................................................................................................................................. ................................................................. 50 2.4 Custom written software and off-the-shelf software ........................................................................................................................... 52 2.5 Compiler and interpreter ..................................................................................................................................................... ................................... 53

6.1 Network types ................................................................................................................................................ ................................................................. 69 6.2 Video and web conferencing ............................................................................................................................................ ................................... 78

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, clearly identifying that data has no meaning

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 and show how data can become information through context and meaning

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 and Explain that information becomes knowledge when human experience is applied

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Exam Practice Questions

Specimen - 2017

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1) Define

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 and give an example

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2) Define

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 and give an example

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3) Define sources

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and explain the advantages and disadvantages of gathering data from direct data

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4) Define sources

 data source and explain the advantages and disadvanta ges of gathering data from indirect data

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• Explain how the following can affect the quality of information:

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Accuracy

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Relevance

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Age

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level of detail and completeness of the information

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• describe the coding of data (including: M for male, F for female) and m ore intricate codes (including: clothing type, sizes and colour of garment) Give examples of

 data:

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• discuss the advantages and disadvantages of the coding of data

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It is common for much of the data collected and entered into a system to have some degree of repetition and redundancy i.e. extra information that does not add anything. And this pattern or repetition is why it is efficient to code the data in some way.

Let's take the example of collecting data about a person's gender. People can be either 'Male' or 'Female'. Whilst these two options are easily understood by all, imagine having to enter the word 'Male' and 'Female' into a system many hundreds of times. It is a waste of time and effort because no extra information is contained in the full words compared to a single letter.

The other issue is that no matter how accurate a person is at d ata entry, at some stage they are likely to make a mistake and might spell 'Male' as 'Mail' or 'Female ' as 'Femal'. This type of mistake will make any results from your database queries unreliable. Instead of entering 'Male' or 'Female' you could code the data a nd instead enter it as 'M' or 'F'. Simply having to enter one letter instead of a possible six will speed up data entry. It will also cut down on the risk of mistakes being made with spelling.

In our example, the words 'Male' or 'Female' have been coded so that they become 'M' or 'F'. When data has been coded it makes it easier to use validation t o check if the data entered is sensible. With the example above, the person entering the data could still make a mistake and enter 'S ' instead of 'M' or 'F'. But if you set up validation so that the field will only accept the letters 'M' or 'F' and absolutely nothing else then that should further cut down on possible mistakes. Note that validation can only check if the data is sensi ble and within reasonable limits, it cannot check whether the data is accurate. Somebody could still enter 'F' instead of 'M'.

Every letter that you store in your database system will take at least one byte of storage. If you store 'Female' as 'F' then you will save five bytes of storage space. If the system belongs to a large organisation, there might be many thousands or millions of records stored - simply by coding one field, a huge amount of hard disk storage can be saved. Faster searching for data It stands to reason that the smaller the size of y our database, the faster it will be to search and produce results. Thus by coding data and keeping the size of the system to a minimum the more time you can s ave in the long run when running queries.

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Analogue to Digital convertor

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Codecs

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• define encryption and describe different methods o f encryption (including: symmetric, asymmetric, public key, private key)

Data Encryption:

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Symmetric Key Encryption (plain text, cypher text and use of a key) Asymmetric Key Encryption (plain text, cypher text and use of a private and public key)

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Cipher Encryption (Substitution and r eposition)

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Encryption is the process of converting information into a form that is meaningless to anyone except holders of a ‘key’.

What is plain text?

In cryptography, plaintext is ordinary readable text before being encrypted into ciphertext or after being decrypted About Cyphers

There are many types of ciphers developed over time. Most common ciphers involved some form or substitution or transposition of alphabetical letters. Substitution means to substitute one character for another w hile transposition is some form of repositioning characters within t he message (which literally scrambles the information). In the digital age, ciphers changed and are generally based on two types of algorithms--one using the same key to e ncrypt and decrypt (symmetric encryption), and one using different keys to encrypt and decrypt (asymmetric encryption). The one that uses symmetric keys falls under private-key cryptography, while asymmetric key algorithms falls under public-key cryptography.

Example of symmetric encryption also known as private-key cryptography

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First Alice needs to generate a secret ‘key’ using encryption software. The key is usually a very long, random number.

Alice must then give a copy of this key to Bob . She must make sure that nobody else can get to the key. (So maybe Alice will visit Bob and give him a copy of the key on a memory stick or floppy disc). Now that Bob has a copy of t he key, each time Alice needs to send him a message she starts by encrypting  it using special encryption software and the secret key. The encrypted message now looks like a jumble of random letters and numbers. Alice then sends the encrypted message to Bob. She can use a public network like the Internet, since, even if it gets stolen, the encrypted message cannot be read or understood without the key .

When Bob receives the message, he uses special decryption software and his copy of the secret key to decrypt the message. Bob can now read the original message from Alice. Advantages

a) Data is scrambled into unreadable form/only person/computer with key can understand data b) increasing the length of a key increases the strength of the encryption Disadvantages:

a) It is slower than normal brows ing. It takes a while for the browser to do the maths required to scramble the message and another delay on the server that has to unscramble the data. b) The recipient may lose the private key. c) It can be a complicated business running a secure server, so very often, ordinary online shops will hire a specialist 'Payment Gateway' such as 'WorldPay' or 'Paypal' to handle payments for them.

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Symmetric Encryption

Symmetric encryption is the oldest and best -known technique. A secret key, which can be a number, a word, or just a string of random letters, is applied to the t ext of a message to change the content in a particular way. This might be as simple as shifting each letter by a number of places in the alphabet. As long as both sender and recipient know the secret key, they can encrypt and decrypt all messages that use this key.

Asymmetric encryption also known as Public-key cryptography Public-key cryptography, also known as asymmetric cryptography, is a class of cryptographic algorithms which require two

separate keys, one of which is secret  (or  private) and one of which is  public. Asymmetric Encryption

The problem with secret keys is e xchanging them over the Internet or a large network while preventing them from falling into the wrong hands. Anyone who knows the secre t key can decrypt the message. One answer is asymmetric encryption, in which there are two related keys--a key pair. A public key is made freely available to anyone who might want to send you a message. A second, private key is kept secret, so that only you know it. Any message (text, binary files, or documents) that are encrypted by using the public key can only be decrypted by applying the same algorithm, but by using the matching private key. Any message that is encrypted by using th e private key can only be decrypted by using the matching public key. This means that you do not have to worry about passing public keys over the Internet (the ke ys are supposed to be public). A problem with asymmetric encryption, however, is that it is slower than symmetric encryption. It r equires far more processing power to both encrypt and decrypt the content of the message.

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On a hard disk

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In e-mail

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On HTTPS websites

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• discuss encryption protocols (including: the purpose of Secure Socket Layer (SSL)/Transport Layer  Security (TLS) and the use of SSL/TLS in client server communication)

Secure Socket Layer (SSL) and Certificates SSL stands for Secure Sockets Layer. It provides a secure connection between internet browsers and websites, allowing you to transmit private data online. Sites secured with SSL display a padlock in the browsers URL . What is SSL used for?

The SSL protocol is used by millions of e-Business providers to protect their customers, ensuring their online transactions remain confidential. A web page should use encryption expected to submit confidential data, including credit card details, passwords or any personal information. All web browsers have the ability to interact with secured sites so long as the site's certificate is from a recognized certificate authority. SSL exists for two reasons: 

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Encryption Hiding what is sent from one computer to another. The data is scrambled up so that it becomes meaningless to someone without the key to decrypt it. Identification

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Making sure that the computer you speaking to is the one you trust

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Encryption Protects Data during Transmission

Web servers and web browsers rely on the Secure Sockets Layer (SSL) protocol to help users protect their data during transfer by creating a uniquely encrypted channel for private communications over the public Internet. Each SSL Certificate consists of a key pair as well as verified identification information. When a web browser (or client) points to a secured website, the server shares the public key with the client to establish an encryption method and a unique session key. The client confirms that it recognizes and trusts the i ssuer of the SSL Certificate. This process is known as the "SSL handshake" and it begins a secure session that protects message privacy, message integrity, and server security.

How does SSL work?

1. 2. 3. 4.

A browser attempts to connect to a website secured with SSL. The browser requests that the web server identify itself. The server sends the browser a copy of its SSL Certificate. The browser checks the certificate root against a list of trusted Certificate Authorities  and that the certificate is unexpired, unrevoked, and that its common name is valid for the website that it is connecting to. 5. The server sends back a digitally signed acknowledgement to start an SSL encrypted session. 6. Encrypted data is shared between the browser and the server and https appears .

What is an SSL Certificate? SSL Certificates are small data files that digitally bind a cryptographic key to an organization’s details. When installed on a web server, it activates the padlock and the https protocol and allows secure connections from a web server to a browser. Typically, SSL is used to secure credit card transactions, data transfer and logins, and more recently is becoming the norm when securing browsing of social media sites. SSL Certificates bind together: • A domain name, server name or hostname. • An organizational identity (i.e. company name) and location.

An organization needs to install the SSL Certificate onto its web server to initiate secure sessions with browsers. Depending on the type of SSL Certificate applied for, the organization will need to go through di ffering levels of vetting. Once installed, it is possible to connect to the website over https://www.domain.com, as this tells the server to establish a secure connection with the browser. Once a secure connection is established, all web traffic between the web server and the web browser will be secure. Browsers tell visitors a website is SSL secure via several visible trust indicators:

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To view the details of an SSL Certificate, go to a secure site, click on the padlock and select “View Certificate”. All browsers are slightly different, but the Certificate always contains the same information.

SSL Certificate Details To view the actual contents of the Certificate click the "Details" tab:

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Detailed steps on how SSL works: https://www.youtube.com/watch?v=iQsKdtjwtYI

Questions: 

What are the two main purposes of SSL?

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Which applications use SSL?

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What is a SSL certificate and what does it contain?

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How does SSL work? Draw a block diagram to represent the steps

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TLS (Transport Layer Security)

Questions: 

What is the purpose of TLS?

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What are the two main layers that make up a TLS?

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How is TLS different to SSL?

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• Define validation …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

presence check

range check

type check

length check

format check

check digit

lookup check

consistency check

limit check

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• define verification …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

Analyse verification methods (including: visual checking and double data entry) 

Visual Checking

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Double Entry

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• explain the need for both validation and verification …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

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Computer hardware is the collection of physical elements that constitutes a computer system. Computer hardware is the physical parts or components of a computer, such as the monitor, mouse, keyboard, computer data storage, hard disk drive (HDD), graphic cards, sound cards, memory, motherboard, and so on, all of which are physical objects that are tangible. In contrast, software is instructions that can be stored and run by hardware.

• Evaluate devices (including: central processing unit (CPU), motherboard, random access memory (RAM), read only memory (ROM), graphics card, sound card, hard disk drive (HDD), solid state drive (SSD))

INTERNAL HARDWARE

What does it do?

Central processing unit

Main internal memory (RAM)

Other internal memory (ROM)

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Motherboard

Graphics cards

Sound cards

Hard Disk Drive

Solid State Drives

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• evaluate  (including: cloud, monitor, keyboard, mouse, printer (laser, inkjet, dot matrix, plotter), speakers, camera (digital, video), web cam, scanner, magnetic ink characte r reader (MICR), optical mark reader (OMR), optical character reader (OCR), bar code reader, pen drive, portable hard disk drive, blue-ray disk drive, memory card)

EXTERNAL HARDWARE Cloud

Monitor

Keyboard

Mouse

Laser Printer

Inkjet

Dot matrix

Plotter

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Speakers

Camera (digital, video)

Web cam

Scanner

Magnetic ink character reader (MICR)

Optical mark reader (OMR)

Optical character reader (OCR)

Bar code reader

Pen drive

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Portable hard disk drive

Blue-ray disk drive

Memory card

In the exam you will expected to: *Explain the purpose of input and output devices *Evaluate different input, storage or output devices for a given task

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• Explain the purpose of storage devices …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………..

• Evaluate storage devices (including: magnetic tape drive, optical, hard disk drive (HDD), solid state drive (SSD))

What is it?

Advantages

Disadvantages

Magnetic tape drive

Optical Drives

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What is it?

Advantages

Disadvantages

Hard disk drive (HDD)

Solid state drive (SSD)

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•

Software Type 1: …………………………………………………………………

Windows

Software Type 2: ……………………………………………………….

MAC

Linux

Software can be described as ……………

Operating system/systems software is ……………….

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Specimen - 2017

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• interpreters)

 (including: compilers, linkers, device drivers, operating systems and utilities,

An operating system controls the operation of the computer system by managing the computer's memory, processes, and all of its software and hardware. Without the operating system the computer will not work. Describe the following features of systems software: Device drivers

Utilities

Compilers

Interpreters

Linkers

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• evaluate application software (including: word processing, spr eadsheet, database management systems, control software, measuring software, applets and apps, photo editing software, video editing software, graphics manipulation software, communications software, web authoring software)

Word processing

Spreadsheet

Database management systems

Control software

Measuring software

Applets and apps

Photo editing software

Video editing software

Graphics manipulation software

Communications software

Web authoring software

*evaluate application software for a given task

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• evaluate the characteristics of different types of user interface (including: command line interface,  graphical user interface, dialogue interface, gesture based interface)

Graphical User Interface (GUI)

Windows

W I M P

Other GUI operating systems:

A Command Line Interface (CLI) Windows Command Prompt

Characteristics :

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Dialogue Interface

Characteristics:

Gesture Based Interface

Characteristics:

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Advantages

Disadvantages

  e   c   a    f   r   e    t   n    i   r   e   s   u    l   a   c    i    h   p   a   r    G

  e   c   a    f   r   e    t   n    i   e   n    i    l    d   n   a   m   m   o    C

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Advantages

Disadvantages

  e   c   a    f   r   e    t   n    I   e   u   g   o    l   a    i    D

  e   c   a    f   r   e    t   n    I    d   e   s   a    b   e   r   u    t   s   e    G

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• evaluate the use of colour, layout, font size, quantity of information and controls when designing a user interface

Colour

Font size

Layout

Quantity of information

Controls

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• evaluate mental models and how they can be used when designing a user interface

A mental model is an explanation of someone's thought process about how something works in the real world . 

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Mental models Mental models Mental models Mental models allow accurate

include what a person thinks is t rue, not necessarily what is actually true. are similar in structure to the thing or concept they represent. allow a person to predict the results of his actions. are simpler than the thing or concept they repre sent. They include only enough information to predictions.

We can portray mental models using several key parts: 1.

 (needed if the mental model is of a physical thing) . If the mental model is of a physical object, the model should contain a simplified image that serves as a template f or that object

2.

 (needed if the mental model has a process). If the mental model is of a process, it should contain some sort of description of that process. The best way to present the script will vary —it might be a series of steps expressed verbally, a flowchart, or a decision tree.

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• Define utility software …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… • Describe the role of different utility software (including: anti-virus, back-up, data compression, disk defragmentation, formatting, file-copying, and deleting)

Anti-virus

Back-up

Data compression

Disk defragmentation

Formatting

File-copying, and deleting

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• compare the benefits and drawbacks of custom written software and off -the-shelf software

Advantages

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Disadvantages

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• describe the function of a compiler  and an interpreter The programmer will choose to use a certain computer language with which to w rite code. For example they may favour the language C++ or they may choose Python. In either case the programmer writes a series of statements to form his computer program. These statements are called The purpose of a 'compiler' is to translate source code into machine code. The code a compiler generates is stored as an 'executable file'. Another name for an executable file is the 'object file', (not a generally popular term but your exam question may mention it). When this file is run, the machine code commands that it contains begin to be processed by the CPU. A compiler produces fast, efficient code that are stored as an executable file. Once the compiler has done its job,  you can pack it away. Just run the 'exe' file. So why are there different ways of doing things? Why b other with interpreters? An interpreter will translate each line of source code into machine language and then execute that machine code directly. An example of this is entering instructions on a BASIC interpreter command l ine.

Advantages of interpreters 1. Debugging

Imagine you are busy programmer and you want to make sure that each line of the source code you are typing in, is error free. As we have mentioned, simple typos will trip you up, miss a comma, semi colon, bracket in the grammar of the high level language and you wiill see a long, de-moralising, list of errors to be fixed in your source code (many of which are spurious, adding to the hassle!). What if a program could check each line of code as you generate it. This is one important role of interpreters, it makes debugging simpler as it immediately checks your source code. 2. Less memory

Another advantage is memory. It uses less memory than an exectuable fil e because only a few lines of source code needs to be in memory at any one time. 3. Less prone to crashing

Some interpreters execute code within a 'virtual machine'. For example the Flash Player and the Java Virtual machine. These have been designed to dis-allow code from directly accessing the computer. So you may crash the virtual machine with faulty code, but most likely the host computer will still be running just fine.

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Disadvantages of interpreters The biggest disadvantage is speed. Interpreted code runs slower than compiled code. This is because the interpreter has to analyse and convert each line of source code (or bytecode) into machine code before it can be executed.

Compiler

Interpreter

Fast, creates executable file that runs directly on the CPU

Slower, interprets code one line at a time

Debugging is more difficult. One error can produce many spurious errors

Debugging is easier. Each line of code is analysed and checked before being executed

More likely to crash the co mputer. The machine code is running directly on the CPU

Less likely to crash as the instructions are being carried out either on the interpreters' command line or within a virtual machi ne environment which is protecting the computer from being directly accessed by the code.

Easier to protect Intellectual Property as the machine code is difficult to understand

Weaker Intellectual property as the source code (or bytecode) has to be available at run time. For example if you write a Flash Actionscript application, you can easily get de-compilers that convert the p-code back into a ctionscript source code (unless you use encryption, but that is another story).

Uses more memory - all the execution code needs to be loaded into memory, although tricks like Dynamic Link Libraries lessen this problem

Uses less memory, source code only ha s to be present one line at a time in memory

Unauthorised modification to the code more difficult. The executable is in the form of machine code. So it is difficult to understand program flow.

Easier to modify as the instructions are at a high level and so the program flow is easier to understand and modify.

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Specimen - 2017

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Candidates should be able to: • identify a range of  sensors and describe their use in monitoring technologies

Moisture

Sensor

Temperature

Pressure

Gas

Sound

Light Humidity

PH

Magnetic field

Infra-red

How it works Produces a signal that depends on the concentration of water vapor in the atmosphere

Produces a signal based on the temperature of its surroundings

Produces a signal that depends on the pressure to which it is exposed

Produces a signal that depends on the level of light falling on it.

Produces a signal based on the invisible IR r adiation falling on it

Produces a signal based on the concentration of gas or vapor .

Produces a signal based on the moisture of soil or judge if there is water around the sensor

Produces a signal based on the field around permanent magnets, coils, and electrical devices. It features a rotating sensor tip to measure both transverse and longitudinal magnetic fields. Produces a signal based on the alkalinity and acidity in a solution

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• identify a range of sensors and des cribe their use in control technologies

• evaluate the use of monitoring technologies in everyday life (including: CCTV monitoring, environmental  monitoring, workplace monitoring)

Create a PPT presentation on the following monitoring technologies:

  

CCTV monitoring Environmental monitoring Workplace monitoring

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• evaluate the use of control technologies in everyday life (including: household appliances, car park  barriers, traffic lights)

Air Conditioning System Touch screen is used to input the required temperature 1.

Temperature sensor collects data about the room temperature

2. The temperature sensor sends data to the analogue to digital convertor 3. The convertor converts the analogue data into digital format 4. The convertor sends the data to the micro-processor 5. The microprocessor compares the temperature of the room to the value

preset

6. If temperature of the room is above the pre-set value the fans remain on/are switched on by the microprocessor or microprocessor increases their speed 7. If temperature of the room is below the pre-set value the fans remain/switched off by the microprocessor

Central Heating System 1.

A number pad is used to input the required temperature.

2. Temperature sensor monitors temperature of room 3. Data from the sensors is converted to digital (using an ADC) 4. The convertor sends the digital signal to the micro-pr ocessor 5. Microprocessor compares temperature data from the sensor with the pre-set value 6. If the temperature is higher/lower than preset value a signal is sent to the actuator 7. if lower microprocessor/actuator switches the heater on 8. if higher microprocessor/actuator switches the heater off

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Refrigeration 1.

A knob allows users to set the desired temperature

2. Temperature sensor monitors temperature of the fridge 3. The temperature sensor sends data to the analogue to digital convertor 4. The convertor converts the analogue data into digital format 5. The convertor sends the data to the micro-processor 6. Microprocessor compares temperature data from the sensor with the pre-set value 7. If the temperature is higher/lower than preset value a signal is sent to the actuator 8. if lower microprocessor/actuator switches the cooler on 9. if higher microprocessor/actuator switches the cooler off

Intensive Care 1.

Sensors monitor the patient’s heart  rate, pulse rate, body temperature, blood pressure

2. The computer is pre-set with normal range of values which is compared with the ones fed back by the sensors 3. The sensors sends data to the analogue to digital convertor 4. The convertor converts the analogue data into digital format 5. The convertor sends the data to the micro-processor 6. Microprocessor compares the data from the sensor with the pre-set value 7. Microprocessor compares the data from the sensors with the pre-set values 8. If the data received is higher/lower than the pre- set value then the computer sounds an alarm for the Medical staff’s attention

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• explain why personal data should be kept confidential …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

• describe how personal data can be gathered by unauthorised persons (including: by smishin g, vishing, phishing and pharming), and how this might be prevented

  g   n   i   h   s   i   m   S

  g   n   i   h   s   i   V

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  g   n   i   h   s   i   h   P

  g   n   i   m   r   a   h   P

• discuss why e-safety is necessary …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

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• describe malware issues (including: Trojan Horse, worms, spyware, adw are, rootkit, malicious bots,  ransomware)

Trojan Horse

Worms

Adware

Malicious Bots

Ransomware

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Specimen - 2017

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• describe a range of potential health issues that could arise from using IT

Health Problem

What causes it?

How can it be prevented?

Repetitive Strain Injury (RSI)

Back and Neck Problems

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Health Problem

What causes it?

How can it be prevented?

Eye Strain

Head Aches

•

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describe a range of safety issues relating to the use of IT

Safety Issues

Preventative measures

Trip hazards e.g. trailing cables

Water by machines

Overloaded sockets

Electrocution

Heavy equipment falling

Over heating

Fire

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• Explain that the digital divide refers to the gap between people and regions that have access to aspects of modern technology (including: telephone, television, personal computers and the internet), and those that do n ot or those that have restricted access

• –– people in cities and people in rural areas …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... –– the educated and the uneducated …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... –– socioeconomic groups …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………...

–– more and less industrially developed nations …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………...

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–– high and low performance computers, wireless connections …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………... …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………...

Specimen - 2017

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• discuss the advantages and disadvantages of networking computers Advantages

Disadvantages

•

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Compare the characteristics of a local area network (LAN) with a w ide area network (WAN)

Local area Network (LAN)

Wide Area Network (WAN)

• describe client-server and peer-to-peer networks

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• describe the characteristics and purpose of virtual private networks (VPN)

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• discuss the advantages and disadvantages of different network types (including: client-server, peer-to-peer, VPN)

  r   e   e   P   o   t   r   e   e   P

  r   e   v   r   e   S   t   n   e   i   l   C

  k   r   o   w   t   e   N   e   t   a   v   i   r   P   l   a   u   t   r   i   V

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• describe the characteris tics and purpose of the internet, intranets and extranets

  t   e   n   a   r   t   n   I

  t   e   n   a   r   t   x   E

  t   e   n   r   e   t   n   I

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• describe how the internet is used for communication (including: IM, VOIP and news services)

  P   I   O   V

  M   I

  s   e   c   i   v   r   e   S   s   w   e   N

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• discuss the benefits and drawbacks of using the internet Advantages

Disadvantages

• Explain the difference between the internet and the World Wide Web …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

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Specimen - 2017

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• discuss the advantages and disadvantages of mobile networks Advantages

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Disadvantages

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• describe how to set up a video conference  required:

 required:

Process of setting up a video conference

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• describe how to set up a web conference  required:

 required:

Process of setting up a web conference

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• describe the use of networks in video and w eb conferencing (including: Integrated Services Digital Network (ISDN), LAN, WAN, VPN, 802.11 a/b/g/n (wireless), Asynchronous Digital Subscriber Lines (ADSL), Synchronous Digital Subscriber Lines (SDSL), 3G/4G mobile networks)

  l   a   t   i   g   i   D  )   s  N   e  D   c   I   i   S   (   v   r   e  k   S  r   o   d  w   t   e   t   e   a   r  N   g   e   t   n   I

  n   /   g  )   /  s   b  s   /  e   a  l   e   i   1  r   1  .   w   (   2   0   8

  s   e   n   i   L   r   e   b   i   r   c   s   b   u   S  )   l   L   S   a   t   i   D   g  A   i   (   D   s   u   o   n   o   r   h   c   n   y   s   A

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  r   e   b   i   r   c   s   b   u   S  )   l   L   S   a   t   i   D   S   g   i   (   D  s   s  e   i   u  n   o  L   n   o   r   h   c   n   y   S

  s   k   r   o   w   t   e   n   e   l   i   b   o   m   G   4   /   G   3

  N   A   L

  N   A   W

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• discuss the impact of video conferencing on society (including: the general public, legislation, education,  medicine, business, media)

  c   i   l   b   u   p   l   a   r   e   n   e   G

  n   o   i   t   a   l   s   i   g   e   L

  n   o   i   t   a   c   u   d   E

  e   n   i   c   i   d   e   M

  s   s   e   n   i   s   u   B

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• describe how data is transmitted and converted in a video conference (including: use of codecs)

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• describe the components of an expert system

  e   s   a   B   e   g   d   e   l   w   o   n   K

  t   r   e   p   x   E

  e   n   i   g   n   E   e   c   n   e   r   e   f   n   I

  e   c   a   f   r   e   t   n   I   r   e   s   U

• explain how the components of an expert system produce possible solutions …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

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• explain how an expert system can be used by organisations …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

• describe the terms backward chaining and forward chaining …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… …………………………………………………………………………………………………………………………………………………………………………………………………… ……………………………………………………………………………………………………………………………………………………………………………………………………

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• explain the use of master and transaction files (including in: pay roll and customer orders) A payroll system is software which organizes all the tasks of employee payment and the filing of employee taxes. It involves:      

Keeping tracking of hours calculating wages calculating taxes and deductions Printing of pay slips Transferring wages to bank accounts Paying employment taxes to the government.

Contains the transactions; changes that are supposed to be made to the data in the master file. For example, each of the following employees have earned the following for this particular week. Each transaction has a code which tells the computer what to do with the data in the transaction file. For example: A – Addition - Add a record C – Change – Change a record D – Delete a record

Holds the actual data that is supposed to be processed and holds the resultant data after the process is completed (updated salaries from the transaction file.) The data can be organized using keys.

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1. The transaction file is sorted in the same order as the mast er file e.g. By an ID such as employee number 2. The computer reads the first record record in the transaction file and the first record in the master file 3. If the IDs don‘t match the computer writes the master file record to the new master file 4. Then write the information from the old master file with the updates from the transaction file to the new master file. 5. If the transaction relates to rate of pay , the c omputer calculates the pay using the rate of pay from the master file and hours worked from the transaction file. It also deducts any taxes from total pay. 6. Processed record is written to master file and the process is repeated until the end of the master file 7. If transaction relates to deletion or amendment the then the old master file record is not written to the new master file 8. If amendment or insertion is required then the data in the transaction file is written to the new master file

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