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WelcomeWelcome to… to…

T. Jumana Abu Shmais – AOU - Riyadh

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Agenda

□ Essentials

□ Getting Help

□ Course Tour

□ Unit 1: Data and Information

□ Unit 2: Representation

□ What’s Next

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Essentials

• Know your course!Read the Course Guide, skim the units…etc. This will help you to:• Make sure that this is the right course for you (if it’s not a

mandatory for your major);• Know what you’re stepping into and plan and manage resources

(time) accordingly;• Keep your expectations real.

• Don’t rely merely on tutorial sessions and summaries.

• Avoid: late submissions and plagiarism

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Getting Help

• Learning Management System (LMS)– TMA submission & Quizzes (MEs)– E-Conferences (forums)– Private massages– Chatting– Supporting materials (Files, SAQs …etc.)– TMA feedback– E-Library

• Face-to-face meetings (tutorial sessions)

• Your Tutor

• Student study groups

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Agenda

Essentials

Getting Help

□ Course Tour

□ Unit 1: Data and Information

□ Unit 2: Representation

□ What’s Next

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DATA COMPUTING AND INFORMATION … What’s in a title?

• DATA (such as a person’s name, or the number of a bus route)

• COMPUTING computers and how they can be made to work with data (e.g. storing it, changing it, and displaying it)

• INFORMATION (which is generated by linking items of data to answer questions of interest).

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Course Aims Summary

To help you attain and improve:• Knowledge of facts and concepts relating to the course themes.

• Computing skills: The course aims at making you a better computer user. You will learn how to write simple computer programs to solve problems.

• Study Skills: Because this is a level 1 course there is a lot of emphasis on developing and improving study skills. With good study skills you can make a success of any course. Some of the skills that you’ll learn:

Time Management Effective WritingCritical Reading Communicating OnlineNote Taking Finding Information on the Web

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The Course Blocks

Block 1: DATA– Capturing data – Representing it– Storing and Sending it

Block 2: COMPUTING – Hardware and software– Software and Programming Concepts– Programming in JavaScript

Block 3: INFORMATION – Human Computer Interaction– Multimedia– Security and Cryptography

Block 1 Unit 1

Unit 2

Unit 3

Unit 4

Unit 5

Block 2 Unit 6

Unit 7

Unit 8

Unit 9*

Unit 10*

Block 3 Unit 11

Unit 12

Unit 13

Unit 14

Unit 15

Unit 16

Part I

Part II

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Assessment

4 TMAs,

2 Quizzes(Midterm Exams)

and

2 Final Exams.

TMA01 8%

TMA02 10%

Quiz 1 7%

Final Exam 1 25%

TMA03 10%

TMA04 7%

Quiz 2 8%

Final Exam 2 25%

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Agenda

Essentials

Getting Help

Course Tour

□ Unit 1: Data and Information

□ Unit 2: Representation

□ What’s Next

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Data, Information and Computers•Data: A discrete (separate or distinct) item such as a number,

character, symbol…etc.

Must be interpreted, by a human or machine, to derive meaning

•Information: The item of knowledge created by linking together two or more items of data. Information is interpreted data.

•Computers: Used to manipulate, analyse and store data and turn it into information.

A computer system is the combination of:– the computer (with its processor and storage);– other equipment (peripherals – input/output devices);– the software programs that make it all work.

The word ‘data’ is the plural of the Latin word ‘datum’ but it is generally used as a singular word in English.

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Sensing data and turning it into something usable (Making sensation make sense)

• Perceptual Data: What we perceive with our senses (the most primitive form of data).

• human beings don’t just react instinctively; they respond reflectively, using thought. In other words, we seek to name, to classify and finally to understand and communicate what we perceive.

• A sign or symbol is a way of representing data. For example, the word ‘blue’ is a sign of a particular color sensation.

• A sign (or symbol) can be defined as something that conveys some information by means other than direct representation.

• Types of signs:• visual• Audible • Tactile (e.g. The Braille System – Louis Braille)

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One person’s data could be another’s informationThe distinction between data and information isn’t always very clear.

Whether something is data or information depends partly on the perspective of the user. Data becomes information in users’ minds when it informs them e.g. answers a question.

Human beings turn data into information through a process of:

– creating signs to represent the data;– agreeing on what the signs symbolize;– linking these signs in a variety of ways to create information;– communicating that information to other people.

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Computers as tools for finding

1. Geographical Locations

2. Information

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1. Geographical Locations

• Maps can be made up of separate layers of geographical data, such as:– the underlying grid of latitude and longitude;– contour lines showing altitude;– features such as rivers, roads, buildings and boundaries;– the names of towns, roads, hills, rivers and other notable

features of the landscape.

Such geographical data will usually be stored in databases (to eliminate duplication by reuse) in a form that computers understand.Applications: constructing maps – route-planning services

Fitness-for-Purpose: adding or removing layers makes a map fit for a specific purpose. Computers facilitate that.

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GPS: Global Positioning System

Hand-held GPS

receiver

The system involves a network of satellites in orbit around the earth, which provide specially coded signals that can be processed in a GPS receiver. Signals from four GPS satellites enable the computer in the receiver to compute the receiver’s position and update the map accordingly (transforms data into information).

The worldwide GPS is funded and controlled by the US Department of Defense (DOD)

Applications:• Navigation (audible directions)• Tracking• Surveying • Plate tectonic studies

GPS is an example of how a computer can transform data into information in ways not previously thought possible.

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2. Information

• The World Wide Web (Web) is the collection of linked data stored on the Internet which is accessed using a browser. It’s a vast storehouse of ever changing, linked information.

• The Internet refers to the physical interconnection of large numbers of smaller data communications networks to form a huge, publicly accessible ‘network of networks’.

• A browser is a computer application used to access the Web. (e.g. Internet Explorer, Firefox …etc.)

Search Engines - Gateways

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Search Engines

• Search Engine: The computer program that uses keywords to facilitate finding things on the Web.

• A computer program is essentially a step-by-step set of instructions that tell the computer what to do.

The process:1. The keywords are transmitted over the Internet to a special computer

known as a web server. This web server contains an index to websites. Each website is associated with a series of keywords which can be found in the site’s title, address or contents. The index keywords and the user’s requested keywords are compared by the server.

2. The web server then retrieves references to those websites that contain the right keywords and sends details of each reference back to the user’s browser.

3. The browser then displays the references for the user.

Here, data (the keywords) is used to assemble information (the references to websites)

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Gateways

• A gateway on the web is a website intended to direct users to other pre-selected websites containing information on a particular topic.

• University librarians often set up gateways for particular areas of study.

A gateway can also refer to a computer that acts as a message router on the internet.

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Computers as tools for working with data• Combining simple elements of data can generate a huge amount of

complex information.• Computers, using only two symbols (0/1) that can be combined

according to simple rules, can produce an infinite number of outputs.

• The flexibility of a computer system is key to being able to use them creatively. It is the computer program (software, in general) that makes such flexibility possible.

• advantage of the computer as an artist’s tool is that it can produce effects that would be difficult or impossible using traditional media.

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Controlling Things using computers

• Virtually all electronic appliances sold in the last decade or so are controlled using microcomputers (microcontrollers) of some type. Before that, such control was provided by mechanical systems (wear, break down, replacement, limited complexity).

• To work, the microcomputer connects to – actuators that cause mechanical parts of the system to work;– sensors that sense the state of some aspect of the machine.

• The user controls the machine through a user interface. Generally, a user interface is a display/control panel that enables the user to control a machine or interact with a program.

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Selling Things using computers

• Web-based selling seems to be concentrated in three main categories of company:– existing catalogue sales companies which have put

their catalogues online to allow customers to buy using the web;

– existing companies whose products are largely information and which have used the web as a means of providing a personalized service or one with a very quick response; (the most financially successful – e.g. publishers)

– companies which have started from scratch using the Web as their only sales medium (e.g. Amazon).

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Using a Sales WebsiteA visitor to a sales website is usually able to:

• browse through the details of the goods for sale;• search for a particular product;• check on the availability of goods;• read reviews of the products by other purchasers;• register to receive newsletters which detail new items of

interest;• buy products using credit or debit cards, and in some

cases, other payment methods such as cheques.• see what items are most popular;• check the status of their order.

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Security: are your credit card details safe?You can be reasonably confident of buying from aWebsite if it displays one of two things:

Another safety precaution is to deal only with Websellers you know are reputable.

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Database Servers

• To be able to search a website requires not only a web server but a database server. Like a Web server, a database server is a computer that responds to requests from other computers. Its task is to find and extract data from a database.

• The Web and database servers form part of a distributed system. This means that separate computers exchange data and information across a network (e.g. Internet) to produce results for a user.

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Agenda

Essentials

Getting Help

Course Tour

Unit 1: Data and Information

□ Unit 2: Representation

□ What’s Next

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Communication, conventionand representation

• Communication is the act of imparting information.

• Communication relies on agreed representations (conventions) which associate a symbol with a meaning.

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We use computers to:

• communicate with each other. (chat, e-mail…etc.)

• solve problems. This implies that:– we need to communicate with computers;– computers need to communicate with us;– computers need to communicate with each

other

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E-m il

• Netiquette • Emotions

• Pros:immediate . global . cheap . multimedia

• Cons:– less time for reflection;– the risk of sending mail to the wrong person(s) is high (BCC and

Reply);– short informal communication (which is not always appropriate);– easily misunderstood.

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Using computers to solve problems

To be able to delegate problems to computers, four-way communication is needed.

1. Programmers need to instruct computers how to solve the problem given a variety of inputs.

2. Users need to give computers the inputs to a particular problem.

3. Computers need to communicate the solution (or lack of one) back to users.

4. For tasks or problems which require more than one computer, the computers need to communicate with each other to share the problem.

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Communication, conventions andprotocols• A convention is an agreement between a

collection of participants about what a message means.– Public– Local– Private

• A human language is based on conventions shared by its speakers.

• A protocol is one of the systems of conventions designed to enable communication with and between computers.

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Important Internet Protocols• TCP/IP (Transmission Control Protocol/Internet Protocol)

– TCP takes data and bundles it up in appropriate parcels for transmission.

– IP moves the parcels along networks and makes sure they are delivered to the right address.

• FTP (File Transfer Protocol) lets authorized users download files from (or send – upload - files to) any other computer connected to the network.

• SMTP (Simple Mail Transfer Protocol) transfers e-mail across the world via the network.

• HTTP (HyperText Transfer Protocol) is a Web protocol that facilitates communication between Web servers and browsers.

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Representation

• A representation is an association between a form (symbol) and a content (meaning) which follows some convention.

Form (symbol)

Meaning/content: EURO (currency)

The association between a particular form and its content is not predetermined. It’s up to people’s choice.

Why are representations central to the ability to communicate?

Because they allow content (meaning)

to be given a symbol (form) that can be perceived by others.

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Effective Representations

1. Must be perceivable in some way;– Auditory – perceived as sound – spoken

language– Visual – perceived as sight – traffic signs– Tactile – perceived by touch – mouse,

keyboard, vibration

2. The relationship between form and content is shared by all parties involved in the communication process.

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Some useful properties ofrepresentations1. Context sensitivity

This is because the same form may be associated with different meanings, depending on the context.

2. AmbiguityAn ambiguous representation is one which associates the same form with more than one meaning in the same context. Uncommon in communication with or between computers.

3. PrecisionReplacing a more precise representation with a less precise one results in information loss.

4. RedundancyA representation contains redundancy if the meaning or content can be recovered from only a part of its form.Compression (detection and removal of redundancy) is important in computing. [Lossy/Lossless]

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Picking Representations• Choosing a representation that is fit-for-

purpose can make a task easier to accomplish, and vice versa.

• To be fit-for-purpose, a representation must contain sufficient information for the purpose, while stripping away irrelevant detail.

• This stripping away of irrelevant detail is an example of a process called abstraction. Abstraction is a process of fitting a problem to the most effective representation.

ProblemAbstraction Fit-for-purpose

Representation

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Complex Representation Systems• Few representations are independent and most belong

to some complex representation system which is assembled out of simpler representations according to predetermined rules (which govern both form and content).

• Complex representation systems have two characteristics:1. The form is made up of several more basic parts; and2. The meaning is constructed from the meanings of the more

basic parts in some systematic way.

• Complex representations are central to computing. All computer languages, including protocols, formats and programming languages are instances of complex representation systems.

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Examples of complex representation systems

symbol & color

number

shape & color

symbol or number

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Representation Systems and Languages

• Where there is a predictable relationship between form and content, the representation system becomes a language. (e.g. traffic signs)

• Computer languages are not so different in principle from human languages but they are a lot simpler and they are never ambiguous. They are formal languages: artificial languages where, given the right context, each expression has exactly one meaning.

Examples of computer languages: Protocols, programming languages and fileRepresentations (formats)

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Sharing and Formats

• Formats are formal languages used to represent the detail of the input and output associated with particular applications.

• Document formats are necessary for two reasons:1. They ensure consistency. Applications need to be

able to display a document in the same way every time it is opened.

2. They enable sharing. If a format is shared, or ‘understood’ by two applications, then they can exchange inputs and outputs.

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The power of formats

• Formats not only enable sharing: they can also prevent it.

• Types of formats:– Proprietary: belong to a particular software vendor.

(Microsoft Word)– Public: free to all (HTML)

• There are two ways of achieving compatibility between formats:– Standards: emerge from a wide group of users

agreeing to use a particular format (de facto) or from deliberate standardization.

– Conversion: translating between the formats.

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Filenames and extensions

• Windows systems list filenames in two parts separated by a dot:

1. the name you provide when saving the file;

2. the file extension.

• A file extension is a relatively short sequence of letters that denotes the format (representation) the file is held in.

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Agenda

Essentials

Getting Help

Course Tour

Unit 1: Data and Information

Unit 2: Representation

□ What’s Next

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Unit 3: Quick glance• Analogue, discrete, digital.

• Number Systems: – Decimal (base 10)– Binary (base 2)– Hexadecimal (base 16)

• Conversions between analogue and digital.

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2Do• Read Unit 3 and practice number system

conversions.

• Read TMA 01 and attempt the questions you can answer at this point.

• LMS: ask your questions, initiate and participate in course-related discussions.

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Any

Questions