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INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

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INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher
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Page 1: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INFORMATION SYSTEM DESIGN AND DEVELOPMENT

Computer Science - Higher

Page 2: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INFORMATION SYSTEM DESIGN AND DEVELOPMENT

Structures and links (database)

National 5

database structure: flat file, linked tables, primary keys and foreign keys

field types (text, number, date, time, graphic, object, calculated, link, Boolean)

validation (including presence check, restricted choice, field length and range)

database operations search, sort (on multiple fields)

good design to avoid data duplication and modification errors (insert, delete, update)

Page 3: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INFORMATION SYSTEM DESIGN AND DEVELOPMENT

Higher

database structures: relational

primary keys, including compound keys

relationships (one-to-one, one-to-many, many-to-many) complex database operations (including queries, forms, reports, calculating

Page 4: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

DATABASE FUNDAMENTALS

Page 5: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

DATABASE FUNDAMENTALS

Page 6: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

RELATIONAL DATABASES

relations that hold multi-valued cells contain repeating data items and where there are one or more of these items they are referred to, collectively, as a repeating group.

Page 7: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

COMPOUND KEYSIn this case we can’t use surname on it’s own as there are three people called KellyWe cant even use First Name and Second Name as there are 2 Connor KellysWe have to have a compound key that would include First Name, Second Name and Date of Birth to uniquely identify each one.

Page 8: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SURROGATE KEYS

The common sense solution to this issue is using Surrogate Keys.

The surrogate key is the SQA number as it is unique for each row and has no connection with the actual data.

Other examples of surrogate keys – Passport Number, National Insurance Number, SQA Number.

Page 9: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

NEED FOR RELATIONAL DATABASES

Name Year Date of Birth

House Group

Guidance Teacher

House Colour

Conor Kelly

4 30/2/99 Morven Mrs Leitch

Red

Jade Stevenson

2 21/2/01 Morven Mrs Leitch

Red

Courtney Smith

3 4/3/00 Morven Mrs Leitch

Red

Adam Love

6 25/12/97 Morven Mrs Leitch

Red

Page 10: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SOLUTIONPupil ID

Name Year

Date of Birth

House Group*

36876 Conor Kelly

4 30/2/99 Morven

85320 Jade Stevenson

2 21/2/01 Morven

56907 Courtney Smith

3 4/3/00 Morven

25935 Adam Love

6 25/12/97 Morven

House Group Guidance Teacher

House Colour

Morven Mrs Leitch Red

Page 11: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ERD

House Group

Pupil

Page 12: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ENTITY RELATIONSHIP DIAGRAMS

Page 13: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ENTITY RELATIONSHIP DIAGRAMS

Page 14: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ENTITY RELATIONSHIP DIAGRAMS

Page 15: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ONE TO ONE

Each pupil has their own individual locker which is used by them alone

Page 16: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ONE TO MANY

Each doctor has many patients but each patient only sees their own doctor

Page 17: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

MANY TO MANY

There are many basketball teams in the leagueEach player is free to play for more than one teamEach player must be linked to at least 1 team Each team must have at least 1 player

Page 18: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS - QUERIESSimple query – Search on only1 field

Page 19: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS - QUERIESComplex query – Search on more than1 field

Page 20: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS – QUERIES, USING TOTALS Using the totals

Page 21: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS – QUERIES, USING TOTALS Same query without using the sum function

Page 22: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS – QUERIES, USING TOTALS

Other than Sum the following functions can also be used

Page 23: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS –USING FORMS

Page 24: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS –USING FORMS

Forms allow inexperienced users to input data

Clicking on the box will open a query by using the Macro on the right

Page 25: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

IMPLEMENTATION IN ACCESS – REPORTSReports provide summarised information for Managers in a format

Page 26: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

STRUCTURES AND LINKS - WEB BASED TOPICS

NATIONAL 5

webpage, page, URL

hyperlink (internal, external), relative absolute addressing

navigation

web browsers and search engines

good design to aid navigation, usability and acccessibility

HIGHER

site structure : multilevel

page structure, including: head, title, body

Cascading style sheets

Meta Tags

dynamic web pages, database-driven website

interactive web page

Page 27: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

HTML – TAGS YOU NEED TO KNOW

• <meta>, <head>, <body>, <div>, <title>, <table>, <tr>, <td>, <hl h6>, <p>, <br>, <font>, <img>, <span>, <video>,

• <a href="http://www.w3schools.com/">Visit W3Schools</a>

• <img src="boat.gif" alt="Big Boat">

• <img src="test.jpg" width=100 height=100>

• http://www.w3schools.com/html/

Page 28: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

HIGHER - HTML & SCRIPTING LANGUAGES

HTML - used to code web pages using a variety of tags

Scripting Languages - add functionality and interactive

features, validate data and access the data behind database-driven websites

They are also used in databases to create Macros

Page 29: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

HTML

• Used to create web pages

• HyperText Markup Language

• Drawback of HTML – it is only a mark up language

• Does not have variables, loops, IF statements, arithmetical or logical operators.

Page 30: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

NEW TAGS FOR HTML5

New semantic elements like <header>, <footer>, <article>, and <section>.

New form controls like number, date, time, calendar, and range.

New graphic elements: <svg> and <canvas>.

New multimedia elements: <audio> and <video>.

Page 31: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

<SPAN> TAG

Inline elements

Page 32: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

<DIV> TAG

Block elements

Page 33: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CREATE YOUR OWN TAGS

Page 34: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CSS

Cascading Style Sheets provide the format and style for a web site in a standard way

This code will set all text on the page to Verdana

Page 35: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CSS TASK

Page 36: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CSS THEORYCreate a style rule for the following

H2 {

Font-family : Arial;

Font – size : 12px;

Color; red;

Font-weight ; bold

}

Text Font Colour Style Size

Headings Arial Red Bold 12

Page 37: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CSS SELECTORS

The element selector defines everything in that tag

Paragraph in this case

p {    font-family: Verdana;    color: blue;}

Page 38: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CSS SELECTORS

The id selector, this will be applied to any html called #para1

#para1 {    font-family: Verdana;    color: blue;}

Page 39: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CSS SELECTORSClass selectors set the layout whenever the class is selected, anywhere in the document.

Page 40: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INTERNAL, INLINE, & EXTERNAL STYLESHEETS

Internal style sheet will set the definition for an html tag in a single sheet

Page 41: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INTERNAL, INLINE, & EXTERNAL STYLESHEETSInline only affects the contents of the individual line

Page 42: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INTERNAL, INLINE, & EXTERNAL STYLESHEETS

An external style sheet is created e.g. and saved as test.css

body{ background-color: gray;}

p { color: blue; }

h3{ color: white; }

Page 43: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INTERNAL, INLINE, & EXTERNAL STYLESHEETS

Save an html file in the same folder with the code<html><head><link rel="stylesheet" type="text/css" href="test.css" /></head><body><h3> A White Header </h3><p> This paragraph has a blue font. The background color of this page is gray becausewe changed it with CSS! </p></body></html>

Page 44: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INTERNAL, INLINE, & EXTERNAL STYLESHEETS PRECEDENCE

Priority

Inline

Internal

External

Page 45: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

META TAGS<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"><html> <head> <title>All our wooden furniture is water proof.</title> <meta name="keywords" content="wood, furniture, garden, garden-table, etc"> <meta name="description" content="Official dealer of wooden garden furniture.">

</head>

<body>

Visit our showroom on weekdays from 9 to 5...

</body></html>

Page 46: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

META TAGS

• Keywords which feature in the <head> tag.

• allows search engines to match website to searches

• Web designers have to anticipate have to anticipate the types of key words users will use.

Page 47: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

DATABASE DRIVEN WEBSITE

all information is stored in a databases on the server, script generates pages that are shown on the site.

Page 48: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

MEDIA TYPES

National 5

text: txt, rtf

audio: wav, mp3

graphics: jpeg, bmp, gif, png

video: mpeg, avi

spreadsheet: xls, csv, xml

Pdf

Factors affecting file size and quality, including resolution, colour depth, sampling rate. Calculation of file size for colour bitmap. Need for compression

Page 49: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

MEDIA TYPES

Higher

Compression:

lossy and lossless compression techniques applied to:

• sound

• graphic

• video

Page 50: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CALCULATION OF THE SIZE OF A PHOTOGRAPH

• Problem

• Wiktoria has bought a 12 Gigabyte flash card. She takes 4 inch by 6 inch photographs with a resolution of 1024 dpi and using 24-bit colour depth. Calculate the maximum number of photographs which can be stored on this card. Show all working.

Page 51: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CALCULATION OF THE SIZE OF A PHOTOGRAPH

Calculate the number of pixels = 4 * 6 * 1024 * 1024

This equals 25165824

Multiply by 24 when you include 24 bit colour

This is equal to 603979776 bits

Now we convert into bytes by dividing by 8

This equals 75497472 bytes

Now divide by 1024 to convert into Kilobytes

This equals 73728 Kb

Now divide by 1024 to convert into Megabytes

This equals 72 Megabytes

Page 52: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CALCULATION OF THE SIZE OF A PHOTOGRAPH

Calculate the number of pixels = 4 * 6 * 1024 * 1024

This equals 25165824

Multiply by 24 when you include 24 bit colour

This is equal to 603979776 bits

Now we convert into bytes by dividing by 8

This equals 75497472 bytes

Now divide by 1024 to convert into Kilobytes

This equals 73728 Kb

Now divide by 1024 to convert into Megabytes

This equals 72 Megabytes

Page 53: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

COMPRESSION

Lossy and lossless compression techniques, applied to

• sound

• graphic

• video

Page 54: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

LOSSY AND LOSSLESS COMPRESSIONType of Compression

Benefits Drawbacks File Types

Lossy Significant reduction in file size

Some loss in quality

JPEG MP3 MP4

Lossless Less reduction in file size

No loss in quality

PNG TIFF MPEG

Page 55: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SAMPLING SOUNDS – TYPICAL SOUND FILE

Page 56: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SAMPLING SOUNDSThis is too low a rate as it will not pick up all of the sounds

Page 57: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SAMPLING SOUNDSThis is at 44,100 samples per second. This ensures it is far more accurate reflection of the actual sound of the song

Page 58: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

HOW DOES IT WORK?It takes advantage of the imperfect nature of the human ear Helps to identify (and discard) unimportant parts of the music: • there are frequencies humans can't hear, • there are frequencies humans distinguish better than

others• when two sounds play at the same time, we hear the

louder sound rather than the softer one.

Page 59: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SAMPLING PICTURES

https://vimeo.com/46248066

Page 60: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

VIDEO COMPRESSION

http://www.youtube.com/watch?v=TrRg0xa4JQA

Page 61: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CODING

National 5

Exemplification and implementation of coding to create

and modify information systems including the use of:

• scripting languages (including JavaScript)

• mark-up languages (including HTML)

Page 62: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CODING

Higher

Exemplification and implementation of coding to create and modify information systems including the use of: scripting (database/web pages)

client-side scripting

server-side scripting optimisation (web search (crawlers) and efficiency of coding)

Page 63: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CLIENT SIDE AND SERVER SIDE COMPARISON

Page 64: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

EXAMPLES OF CLIENT SIDE SCRIPTING

http://mikekus.com/

http://hellomonday.com/

http://multeor.com/game/

http://crimetimeline.io/

http://hereistoday.com/

Page 65: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

THE RULES OF CASCADING STYLESHEETS STATE THAT:

embedded styles within the text over-rule all others

document level styles, defined in the document , over-rule external Stylesheets external stylesheets only apply if they are not over-ruled by the other 2 methods

Page 66: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CASCADING STYLE SHEETS

• A cascading stylesheet (CSS) is a separate file which defines colours, fonts and sizes

• to be used on web pages. A reference to this file is included within every web page in a website.

• This ensures that each page is consistent in format.

Page 67: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.
Page 68: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.
Page 69: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

WEBSITES FOR JAVASCRIPT

Codeacademy

W3C for schools

Page 70: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

JAVASCRIPT

• Allows user interaction

• User validation possible

• Page content can be customised based on time, browser, location

• Javascript blocks popups

• Used for menus and galleries

Page 71: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

FORM VALIDATION

• Need for validation

• Simple VBS validation script

• Mailto:

• Problems with Mailto:

• CGI_bin

• Alert messages

Page 72: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

POPUP BLOCK CODE - EXAMPLE OF JAVASCRIPT

Page 73: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

PHP

• Future development

• Web server processing of hyper text

• MySQL

• Cookies and databases

Page 74: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CLIENT SIDE SCRIPTING (INCLUDING FORM VALIDATION AND ALERTS).

• Server-side scripting is a web server technology in which a user’s request is fulfilled by running a script directly

• on the web server to generate dynamic HTML pages

Page 75: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.
Page 76: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

FACEBOOK DATABASE

Page 77: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

PHP IN ACTION

W3 schools php

Page 78: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.
Page 79: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CLIENT SIDE SCRIPTING

• JavaScript

• VBScript

• Compare JavaScript and VBScript

• Need for client side scripting

• Document.Write command

• Document.Cookie command

Page 80: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CRAWLERS

• Search engines use programs called ‘bots’ or ‘spiders’ or ‘web crawlers’

• Googlebot is Google’s web crawler

• https://www.google.co.uk/insidesearch/howsearchworks/thestory/

• Yahoo’s is called Yahoo!Slurp.

• http://blogs.bing.com/search/2014/04/21/predictions-with-bing/

• These programs scan web servers for new pages and send the information back to the main database.

• This is how Search engines work. When you search, you are going through their database to find relevant pages.

• http://patch.com/connecticut/orange/the-differences-between-google--bing-seo-algorithms

Page 81: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SEARCH ENGINES - OCTOBER 2015

Page 82: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SECURITY PRECAUTIONS

National 5

anti-virus software, passwords/encryption, biometrics, security protocols and firewalls, use of security suites.

Higher

Encryption, digital certificates and signatures, server-side validation of online form data, biometrics in industry

Page 83: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

BROWSERS

• HTML interpretation – X Ray goggles

• client side scripting - http://www.w3schools.com/js/default.asp

• cookie functions - http://www.w3schools.com/js/js_cookies.asp

• built in encryption functions - http://www.w3schools.com/php/func_string_crypt.asp

Page 84: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

COOKIES

Page 85: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ENCRYPTION –SYMMETRIC

key distribution problem

Page 86: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SUBMISSION FORM

Page 87: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

BIOMETRICS IN INDUSTRY

Page 88: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SYMMETRIC ENCRYPTION – PUTTING THE DATA INTO CODE

• A = D

• B = E

• C = F

Plus 3 encryption

Page 89: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ENCRYPTION –ASYMMETRIC

The person who will receive the data decides on a private keyThe RSA algorithm generates a public key which will be used to encrypt the messageit is mathematically (almost) impossible to calculate the private key from the public key.

Page 90: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

PGP – X SEND Y A MESSAGE

1. PGP first compresses the message - harder to decode the message

2. PGP then creates a session key, which is a one-time-only secret key

3. session key itself is encrypted using Y’s public key.

4. AXcrypt

Page 91: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

PGP – Y RECEIVES THE MESSAGE

1. Y’s copy of PGP uses his or her private key to decrypt the temporary session key.

2. PGP then uses the session key to decrypt the encryptedMessage.

This is the most secure and quickest means of encryption

Page 92: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ENCRYPTION IN ACTION

Page 93: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ENCRYPTION IN ACTION

Page 94: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SECURE SOCKETS LAYER

• Implemented by browsers

Page 95: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

FIREWALLS (SECURITY RISKS)

Page 96: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

FIREWALLS (SECURITY RISKS)

The firewall software can be set up to:

• reject packets from selected IP addresses (for example, blocking inappropriate sites)

• allow only packets from selected sites

• reject or allow packets from particular domain names

• only allow packets to and from certain ports (a useful defence against many viruses)

• allow or reject packets using particular protocols (for example, blocking all FTP requests)

• "sniff" packets, and reject any which contain certain words

Page 97: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

TESTING

National 5

links and navigation

matches user interface design

Higher

Beta testing

usability

compatibility issues (including memory and storage requirements, OS compatibility)

Page 98: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

BETA TESTINGThe intended end users are asked to test the software, they are from outwith the software development company.

Page 99: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

USABILITY TESTING

This involves testing software applications like websites and programmes using a real life test group using scenarios which accurately reflect the types of tasks the software is expected to perform.

Page 100: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

COMPATIBILITY

When developing an Information System the developers must ensure it can run on the types of devices users own.

Issue can be

• RAM

• Storage Requirements

• Operating System

Page 101: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

PURPOSE, FEATURES, FUNCTIONALITY, USERS

National 5

Description of purpose Users: expert, novice, age-range

Higher

detailed descriptions of purpose

Interaction of information systems with:

human users: expert, novice, age-range

other software: search engines

Page 102: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

INFORMATION SYSTEM PURPOSE

Before the start of the design process the specific purpose of the information system must be defined. This includes

• data design 

• architecture design  

• interface design  

• procedural design 

Page 103: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

NOVICE, EXPERT, AGE RANGES

Expert users – prefer to use key board short cuts while novice users require menus and detailed explanations.

Page 104: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

AGE RANGE

Certain pieces of information systems are specifically aimed at certain users

Page 105: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SEARCH ENGINES

Page 106: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

SEARCH ENGINES - BAIDU

Page 107: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

BROWSERS

Page 108: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

TECHNICAL IMPLEMENTATION (HARDWARE REQUIREMENTS)

National 5

input and output devices

processor type and speed (Hz)

memory (RAM, ROM)

device type (including supercomputer, desktop, portable devices including laptop, tablet, smartphone

Page 109: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

TECHNICAL IMPLEMENTATION (HARDWARE REQUIREMENTS)

input and output devices

processor type, number and speed (Hz)

memory (RAM, ROM, cache)

device type (including desktop, laptop, tablet, smartphone)

Page 110: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

TECHNICAL IMPLEMENTATION (SOFTWARE REQUIREMENTS)

National 5

web browsers

specific applications and/or utilities

Higher

operating systems

licensing

proprietary versus open source

portability Description and exemplification of current trends in operating system design

Page 111: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

OPERATING SYSTEMS

• Manages the hardware and software of the computer system

• File Management

• Memory Management

• Input / Output Management

Page 112: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

LICENSING

Single License – one use only

Multiple License – more than one person

Site License – allows everyone in the business access to the software.

Freeware – distributed free of charge

Shareware – Trial version given for 30-60 days.

Page 113: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

PORTABILITY

• Software designers have to ensure that their software can be used on as many different devices as possible.

• Helps maximise sales as it can run on different operating systems.

Page 114: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CURRENT TRENDS IN OS• Operating systems have been redesigned to deal

with touchscreen technology.

• Simpler icon based design

• Complex tasks like graphic editing and web design are still better done using a mouse and keyboard.

Page 115: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

TECHNICAL IMPLEMENTATION (STORAGE)

National 5

local, web cloud

capacity (in appropriate units)

rewritable, read-only

interface type

data transfer speed Storage devices: built-in, external, portable, magnetic, optical, solid state

Page 116: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

TECHNICAL IMPLEMENTATION (STORAGE)

Higher

distributed and offline storage

backup systems and strategy

capacity (in appropriate units)

rewritable, read-only

interface type

data transfer speed Storage devices:

built-in, external magnetic, optical, solid state.

Description and exemplification of current trends in storage Systems

Page 117: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

DISTRIBUTED AND OFFLINE STORAGEDistributed – Data is stored in a number of different servers usually different offices but can be accessed by all users in separate locations

Offline – Storage devices like CD ROMs, DVDs, USB Drives etc.

Page 118: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CENTRALISED AND DISTRIBUTED DATABASESCentralised database.

• All the data is held on a central computer- mainframe or server.

• Advantages.• far easier to manage and control • far easier to back up

Page 119: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

CENTRALISED AND DISTRIBUTED DATABASESDistributed Database.

• Consists of two or more files located at different sites on a computer network.

• different users can access it without interfering with one another.

• The DBMS must synchronise the scattered databases to make sure they all have consistent data.

Page 120: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

BACKUP SYSTEMS AND STRATEGY

• Every computer user should have a strategy in place to backup their data.

• This is the process of making a copy of data stored on fixed hard disks to some other media.

• This can be tape, external portable hard disks, writeable CD-ROM, DVD or to the cloud

• This ensures that the most recent copy of the data can be recovered and restored in the event of data loss.

Page 121: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

MOST COMMON REASONS FOR DATA LOSS

1. Deleting files accidentally

2. Viruses and damaging malware

3. Mechanical damages of hard drive

4. Power failures

5. Theft of computer

6. Spilling coffee, and other water damages

7. Fire accidents and explosions

Page 122: INFORMATION SYSTEM DESIGN AND DEVELOPMENT Computer Science - Higher.

ARCHIVE, RECOVERY AND STORAGE METHODS

• Archive.• The process of copying data from hard disk drives to

tape or other media for long-term storage.

• Data verification.• it is important to check that the data stored on the

backup media can be recovered.

• Frequency and Version Control.• Full back up – all the existing data• Differential backup – only the data since the last full backup is

stored• Incremental backup – saves only the data changed since the last

backup of any type

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GRANDFATHER, FATHER, SON

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TECHNICAL IMPLEMENTATION (NETWORKING/CONNECTIVITY)

National 5

peer-to-peer, client/server, wired, optical, wireless

Higher

Cloud systems and server provision: public, private, hybrid cloud-based services

web hosting

current trends in networking and connectivity

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CLOUD SYSTEMS

• Data and software operate on the web rather than a local computer.

• User can access their documents from anywhere.

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SERVER PROVISION: PUBLIC, PRIVATE, HYBRID AND CLOUD-BASED SERVICES

Public Cloud – available to anyone either free or for a fee

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PRIVATE AND HYBRID CLOUDS

Private are based only within an organisation but still stored in the cloud.

Hybrid is a mixture of the public and private systems

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WEB HOSTS

Companies which, for a fee, allow the owners of websites to store a website which can then be viewed on the WWW

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NETWORKING AND CONNECTIVITY

LAN

WAN

Intranet

Internet

3G 4G

Wifi

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SECURITY RISKS

National 5/Higher

spyware, phishing, keylogging

online fraud, identity theft

DOS (Denial of Service) attacks

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SPYWARE

Software that can obtain information from a users computer without them being aware of it.

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PHISHING

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KEYLOGGING

Software which records every keystroke on a PC

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ONLINE FRAUD

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DENIAL OF SERVICE ATTACKS

Attempt to make a computer network unavailable to its users. This can be done by bombarding the server with requests for information until the server can longer cope with amount of traffic.

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LEGAL IMPLICATIONS

Computer Misuse Act, Data Protection Act, Copyright, Designs and Patents Act (plagiarism), Health and Safety regulations, Communication Act

Regulation of Investigatory Powers Act

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LEGAL IMPLICATIONS OF INFORMATION SYSTEMS

• The Data Protection Act 1998

• Copyright Designs and Patents Act 1988

• The Regulation of Investigatory Powers Act 2000

• The Freedom of Information Act (Scotland) 2002

• Health and safety Regulations

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COMPUTER MISUSE ACT

It is illegal to

1. Unauthorised access to computer material.

2. Unauthorised access with intent to commit or facilitate commission of further offences.

3.Unauthorised acts with intent to impair, or with recklessness as to impairing, operation of computer, etc.

3A.Making, supplying or obtaining articles for use in offence under section 1 or 3

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THE 1998 DATA PROTECTION ACT • The 8 Data Protection Principles.

• Personal data shall be processed fairly and lawfully.

• Personal data shall be obtained only for lawful purposes,

• Personal data shall be adequate, relevant and not excessive.

• Personal data shall be accurate and, kept up to date.

• Personal data shall not be kept for longer than is necessary.

• Personal data shall be processed in accordance with the rights of data subjects.

• Appropriate measures shall be taken against unauthorised or unlawful processing of data.

• Personal data shall not be transferred to a country outside Europe.

• Data must be registered with the Data Commissioner.

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THE 1998 DATA PROTECTION ACT

• Unconditional exemptions.• Data related to National Security.• Data which by law has to be made public (e.g.

voters’ roll).• Data held by the Police and National Health

Service.

•  conditional exemptions.• mailing lists (names and addresses).• data used for calculating and paying wages.• information used for club memberships.• data used by a data subject at home.

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THE 1998 DATA PROTECTION ACT • Rights of Data Subjects.

• To see any personal data stored either electronically or manually about them.

• The Data controller may ask that a small fee be paid to cover their costs in providing the data.

• To have their data corrected if it is inaccurate.• To prevent their data being used by companies to send

them junk mail.

• Responsibilities of Data Users.• Have to register with the Data Protection Registrar if

they wished to hold personal information about data subjects.

• They must be willing to let data subjects see data held about them, but must amend any false data without charge.

• Data Users must also be willing to remove subjects’ names and addresses from mailing lists if asked to.

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THE 1998 DATA PROTECTION ACT • Changes From 1984 Act.

• The 1984 DPA had certain shortcomings.• only covered data in electronic form.• companies could circumvent certain provisions.• It had no European or worldwide dimension.• there was no obligation on any data user to tell the

data subject that they held any data about them.

• The 1998 Act.• covers the transmission of data in electronic form,

which was not really an issue in 1984.• harmonised the European Union Data Protection

legislation.• It also made it a requirement of the Act to ask for

the prior consent of data subjects to have data held about them, and included paper based records.

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143

COPYRIGHT, DESIGNS & PATENTS ACT • Software Licensing.

• Software can be legally installed on as many computers as the licence allows.

• Shareware can be used legally for 30 days then either paid for or deleted.

• Freeware can be downloaded and used free of charge.

• Computer Applications.• Databases can store vast amounts of

copyright data.• Act covers extracts from computer

databases.• Plagiarism to copy work directly from the

Web.• Music downloads must be paid for and

copyright checked.• Software piracy a crime - FAST.

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THE REGULATION OF INVESTIGATORY POWERS ACT

2000 • Gives powers to:-.

• Police, Special Branch, GCHQ and MI5.• It allows organisations to monitor employees, e-mail

and Web usage.• It also provides powers to help combat the threat

posed by rising criminal use of strong encryption to try to break into electronic transactions.

• The Act contains 5 parts.• allows the authorities to monitor our personal e-mail

and Internet usage.• businesses, local authorities and government

departments can and do monitor internal e-mails,• monitor Internet usage of staff, students and pupils.

• sounds very “Big Brother.”• May enrage and disturb many people to realise this.• When terrorists can be anywhere in our society it

may be a relief to know that the authorities are taking such steps to catch them.

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145

THE FREEDOM OF INFORMATION ACT (SCOTLAND) 2002

• From 1st January 2005.• General right of public access to all types of

'recorded' information held by public authorities.• sets out exemptions from that general right.• places a number of obligations on public

authorities.• The Act applies only to 'public authorities' and not

to private entities.• Public authorities include Government

Departments, local authorities and many other public bodies, and also schools, colleges and universities.

• The Act will be enforced by the Scottish Information Commissioner.

• Responsibilities of public authorities.• Required to adopt and maintain a Publication

Scheme.• Sets out the classes of information available (eg.

prospectuses, almanacs and websites).• the manner in which they intend to publish the

information,• whether a charge will be made for the

information.

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COMMUNICATIONS ACT

• Protects the public from harmful or menacing electronic communication

• Makes it illegal to use other people's wifi without their permission

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HEALTH AND SAFETY REGULATIONS

• Requirement on employers.• Carry out a risk assessment.• Employers with five or more employees need to

record the significant findings of the risk assessment.

• Risk assessment should be straightforward in a simple workplace such as a typical office.

• Provide a safe and secure working environment.

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NEED FOR INTERNATIONAL POLICING OF THE INTERNET.

Why it won’t happen

- Each country has separate legal systems

- Don’t want to lose control.

- UN style organsiation is required

Why would it be good

- Prevent more crime

- Censorship would be universal.

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ENVIRONMENTAL IMPACT/IMPLICATI ONS

National 5

Energy use, Disposal of IT equipment, Carbon footprint

Higher

Lifetime carbon footprint (manufacture, use, disposal), Environmental benefits

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LIFETIME CARBON FOOTPRINT

• Manufacture - Energy and resources are used to bring together the raw materials for a PC or Laptop.

• The actual production process also requires energy and resources.

• While it is being used the PC/Laptop will be using energy and create heat emissions

• Disposal - Much computer hardware contains emissions that can cause cancer. Therefore they have to be disposed of with care.

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ENVIRONMENTAL BENEFITS

• Communication can take place on-line rather than people travelling to meetings.

• Companies now recycle IT equipment rather than send it to landfill.

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ECONOMIC AND SOCIAL IMPACT

Economic: competitive advantage, global marketplace, business costs, maintainability, scalability

Social: censorship and freedom of speech, privacy and encryption, global citizenship, online communities.

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ACADEMIC, COMMERCIAL AND PERSONAL WEB PAGES

• http://www.cristianoronaldo.com/

• http://www.lilyallenmusic.com/

• http://www.amazon.com/

• http://www.debenhams.com/

• https://retail.santander.co.uk

• https://www.edx.org/

• http://www.st-andrews.ac.uk/

• https://www.whitehouse.gov/administration/president-obama

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COMPETITIVE ADVANTAGE

When they invest in excellent IT systems organisations can gain a competitive advantages over their rivals as this can lead them to offer better value to their customers as they are more efficient.

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GLOBAL MARKETPLACE

Selling products and services across the world rather than just in a single country or regions.

Coca Cola are global.

Barr’s Irn Bru is national.

The VG store in Motherwell is local

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BUSINESS COSTS

Expensive to invest in the hardware and software for a new computerised system.

Staff Training can be expensive.

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MAINTAINABILITY

How easy is it to repair and update any ICT equipment.

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SCALABILITY

Is it possible for an information system to be used to meet a global audience rather than a national or local one.

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CENSORSHIP AND FREEDOM OF SPEECHThe challenge for the authorities is to find a balance between the individuals' right to express themselves freely and the need to protect the public from offence content or opinions.

The authorities in, for example, China and Iran filter the content of websites preventing their citizens from gaining free access whereas in the UK it is only content which is extremely offensive that would be blocked.

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PRIVACY AND ENCRYPTION

Authorities try to reach a balance between successfully preventing and investigating crime and allowing individuals the right to express their own opinions and follow their personal interests.

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GLOBAL CITIZENSHIP

awareness of global issues such as environment, commerce, politics and society in general.

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ONLINE COMMUNITIES

A virtual community whose members interact with each other primarily via the Internet.


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