M150 Data, Computing and Information

1. Dammam Branch M150 Data, Computing and Information Haifaa Elayyan

2. What M150 is about This course is not about the history of computers (although that will be touched on); it’s about: 1. data (such as a person’s name, or the number of a bus route); 2 . computers and how they can be made to work with data (e.g. storing it, changing it, and displaying it); 3 . information (which is generated by linking items of data to answer questions of interest). 4- The course is also about how the use of computers can affect you. Whether or not you realise it, you are not only surrounded by computers but you have a persona created by .the data associated with you Haifaa Elayyan

3. Aims of the course • To explain why people use computers; • Data and information: an introduction demonstrate that the process of using computers begins with human perceptions and is prompted by our curiosity about the world, and our need to control parts of it; • To demonstrate that, increasingly, computers do more than just ‘process’ data: they collect, store and display it as text, numbers, photographs, videos, and so on; • To help you make more effective use of your computer; • To teach you how to program; • To investigate the importance of information to human beings, and show how, when imparting information, the way it’s presented can be as important as its content; • To examine how computers can be used to keep track of people, and how political, legal and ethical issues arise from this; • To examine the limitations of computers, data and information, and enable you to evaluate critically the data and information you come across in your daily life; • To provide you with study skills, such as information finding, and transferable skills, such as the ability to write short pieces of text for different audiences. Haifaa Elayyan

4. Processes data into information Data that is organized, meaningful, and useful Acceptsdata Raw facts, figures, and symbols Produces and stores results What Is a Computer? • How is a computer defined? • Electronic device operating under the control of instructions stored in its own memory Haifaa Elayyan

5. Reliability Speed Consistency Storage Communications Next Advantages and Disadvantages of Using Computers • What are the advantages of using computers? Haifaa Elayyan p. 10

6. Next Advantages and Disadvantages of Using Computers • What are the disadvantages of using computers? Violation ofPrivacy Impact onLabor Force Haifaa Elayyan Health Risks Impact onEnvironment p. 10

7. Computer’s components: Haifaa Elayyan Monitor, mouse, printer, keyboard .. Motherboard, CPU, memory ,buses Dos, windows XP, Vista C++, VISUAL BASIC, SQL, JAVA OFFICE( WORD, POWERPOINT, EXCEL , GRAPHIC DESIGNS .. )

8. How does the Computer Work ? 2 Haifaa Elayyan 1 3

9. DATA AND INFORMATION • Data refers to discrete items, such as the price of an item on the shelf of a supermarket, or the type of product listed on a sign over a supermarket. • In contrast, information involves linking together two or more items of data to provide an item of knowledge. • EXAMPLE : If someone suddenly said to you, ‘50p’, you’d be a bit puzzled. However, being told, ‘The price of a litre of milk is 50p’, would convey information. In other words, information can be thought of as the answer to a question such as: ‘What is the price of this product?’ So the words ‘50p’ said in connection with nothing would mean little, but stated in answer to the above question would convey information or knowledge. Haifaa Elayyan

10. Differences between data and information • The interchange of the words data and information is widespread, but M150 should help you to develop a clearer understanding of the differences between the two. Data • Facts, statistics used for reference or analysis. • Numbers, characters, symbols, images etc., which can be processed by a computer. • Data must be interpreted, by a human or machine, to derive meaning • "Data is a representation of information" • Latin 'datum' meaning "that which is given" • Data plural, datum singular . Information • Knowledge derived from study, experience (by the senses), or instruction. • Communication of intelligence. • "Information is any kind of knowledge that is exchangeable amongst people, about things, facts, concepts, etc., in some context." • "Information is interpreted ( Explain ) data" . Haifaa Elayyan

11. Transforming Data Into Information • Example : Student Details • Each one of the students remembers when they had to fill the online application to register in AOU . There was a form to fill , and the students were asked to enter certain kind of data ( Name, contact number , specify the degree and so on ). • You were presented with a web page and asked to enter certain values. In other words data was collected. • You pressed the submit button. At which point that data was stored and operated on by a program. The program, written in JavaScript, was embedded in the webpage and manipulated the data before displaying some text, marked up in HTML, on another webpage. • In the case of the first form this simply reflected the values you entered. With the second form, the data was operated on in such a way as to display some information about you, i.e. whether or not you . • Once they submitted the form , the data transferred into information can be displayed when it is needed . These exercises encapsulate a major theme of the course, namely the transformation of data into information Haifaa Elayyan

12. Human beings, data, signs andsymbols • We live in a sea of sensation: sight, sound, touch, taste, smell and balance(really a sense of our bodies in three-dimensional space). These sensations, and our ability mentally to process, and then react to and communicate them, are vital to our survival. What we perceive with our senses we call the most primitive form of data: perceptual 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 what we perceive. • Language, one of the defining characteristics of human beings, is a hugely complex system of meaningful sounds which can be combined and repeated. It enables us not only to name and classify our sensations, but also to communicate them and our thoughts about them to others. • About 30,000 years ago human beings began making ‘useless’ objects: items not strictly necessary for survival that they were signs conveying specific meanings to those who made and used them Haifaa Elayyan

13. SIGNS : • A sign (or symbol) can be defined as something that conveys some information by means other than direct representation. Signs represent something other than themselves: they symbolize something. • Signs vary: A beeping sound at a light-controlled pedestrian crossing symbolizes that it’s safe to cross while the beeping continues, an arrow on a traffic sign symbolizes the way to go when it’s not obvious. • Signs can be of many types. There are visual signs (such as road signs), audible signs (beeps) • Coming back to language, words are also signs. The word ‘cow’ symbolizes a particular type of ruminant animal from which we get milk, meat, and sometimes muscle power. The word itself is not a cow; neither is it a particular cow (‘Daisy’); it symbolizes the animal we think of as a cow Haifaa Elayyan

14. SIGNS : • In summary, a sign or symbol is a way of representing data. For example, the word ‘blue’ is a sign of a particular colour sensation; a seemingly-simple word like ‘cow’ is a sign of a complex thought or idea derived from many sensations; a road sign can represent some condition of the road (e.g. that it narrows ahead) and warn the driver to take care. Haifaa Elayyan

15. Binary Number System • Before looking at the binary representation of numbers, it is worth taking a quick look at the representation and meaning of decimal, or denary, numbers. • This system employs a base 10 representation. Another way of describing this is to say that it has a radix of 10, meaning that each digit to the left of the decimal point represents increasing powers of 10 and digits to the right of the point represent decreasing powers of 10. • Consider the decimal number 251, which can be illustrated as follows: • 102=100 101=100 100=100 2 5 1   • In other words, 251 represents the addition of 2x100 + 5x10 + 1x1. • Binary representation (radix 2) simply offers another form of numeric representation by adding increasing powers of 2, rather than 10. Haifaa Elayyan

16. Binary Number System • The decimal value 251 can be represented by the binary representation 11111011. • 27=128 26=64 25=32 24=16 23=8 22=4 21=2 20=1 1 1 1 1 1 0 1 1   • Computer programs operate on data and ultimately enable humans to derive meaning from these representations. • The binary number system is the simplest of all number systems. Its representation requires a combination of just two numbers, 0 and 1, to represent any binary value. 1s and 0s are binary digits or bits. An 8-bit unit is called a byte; employed by most computers as the basic unit of data representation. A byte is a subdivision of a word. • A word is "a vector of bits that is treated as a unit by the computer hardware. The number of bits, referred to as the word length or word size, is now usually 16 or 32. The memory of a computer is divided into words (and possibly subdivided into bytes). A word is usually long enough to contain an instruction or an integer." Haifaa Elayyan

17. How does a computer utilise the binary system? • At its lowest level (machine level) a computer operates by switching on or off millions of transistors at great speed. These transistors, a form of switch, are etched onto the microprocessor/chip. • A computer processes data, held in memory and represented in a binary form or code. Switches that are either "on" or "off" implement this. • A transistor/switch is a two-state device and can be in one of two states: • On, which represents the binary digit 1 • Off, which represents the binary digit 0 • Consequently, 8 transistors with appropriate state can, for example, represent the binary code 11111011. • On OnOnOnOn Off On On Haifaa Elayyan

18. Binary Number System • Example Usage • IP (Internet Protocol) addresses are numeric identifiers and are assigned to any machine on an IP network. They are software addresses and represent encoded information that enables the routing of datagrams, or packets, on the Internet. They consist of four bytes (32 bits). Each byte of an IP address, known as an octet, can take any value with a decimal equivalent of between 0 and 255. Here is a binary value for the IP address of BBC (http://www.bbc.com) • 11010100 00111010 11111011 11000011 Haifaa Elayyan

19. Continue • The decimal equivalent, which is far easier for humans to read, is • 212.58.251.195 • An IP address is written in dotted quad form and in the case of the BBC example, we can write 212.58.251.195 By entering http://212.58.251.195 into a browser, a user can access the BBC website. Note that when you enter http://www.bbc.com into a browser this name is resolved into a number by another computer on the Internet known as a Domain Name Server. (go here for a decription of packet handling and Telnet) • 32 bits is 322-1 or 4294967295 or 4.294967295 x 109 (approx. 4.3 billion, lots of potential addresses, although not enough to satisfy anticipated demand). Haifaa Elayyan

20. Octal Number System • Octal notation offers another means of representing numeric values. Unlike decimal, it is based on 8, or radix of 8, rather than 10, i.e. increasing powers of 8. Octal numbers can be represented by using a combination of 0, 1, 2, 3, 4, 5, 6, 7. For example, the decimal number 1209 is represented in the octal 2271 • = 2x512 + 2x64 + 7x8 + 1x1 • 83=512 82=64 81=8 80=1 2 2 8 1   • 2x512=1024 + 2x64=128 + 7x8=56 + 1x1=1 • An octal digit (0 to 7) can represent 3 bits (000 to 111). Consequently it can be regarded as a shorthand version of binary.Octal notation was widely used to provide a more readable view of binary data. It has been mostly replaced by hexadecimal notation. Haifaa Elayyan

21. Hexadecimal Number System • A base 16 (radix 16) number system, i.e. increasing powers of 16. Introduced by IBM - legend has it that the company refused to countenance the more accurate sexadecimal name. • Besides the numbers 0 ..9, hex uses the letters A, B, C, D, E, and F to represent the decimal equivalents 10, 11, 12, 13, 14 and 15 .For example, decimal value 31 has hex value 1F • 163=4096 162=256 161=16 160=1 0 0 1 F 1F = 1 lot of 16 plus F lots of 1 • A hex digit represents 4 binary digits (0000 to 1111) and two hex digits can represent one byte. This simple segmenting of binary into hex is an improvement on octal representation as a means of viewing binary data in modern machines. However, it is worth bearing in mind that if computers still employed a 6-digit byte, rather than the ubiquitous 8-bit byte, then the octal system, where an octal digit is equivalent to 3-bits, would be better for segmenting and viewing binary numbers. Haifaa Elayyan

22. Hexadecimal Number System • Example Usage • Hex has many applications, of which the following are just a few: • RGB colour representation http://www.lynda.com/hexh.html • NIC (Network Interface Card) MAC (Media Access Control) addresses http://www.cityu.edu.hk/csc/deptweb/facilities/ctnet/wlan/machelp.htm • Extended ASCII Chart used for representing 28 or 256 characters (0 ..255), including all of those on your keyboard plus a few esoteric symbols. Any ASCII value can be represented by a 2 digit hex i.e. 00 .. FF. http://www.asciitable.com/ Haifaa Elayyan

23. Conversion of Numbers • The following offers some rules for conversion of numbers between differing number systems. You may find other approaches that are more suitable (and understandable) e.g. the tabular layout outlined on the previous three pages. Haifaa Elayyan

24. Haifaa Elayyan

25. Examples : • Binary to Octal Conversion : Binary Number 1001001011110101Split into groups of 3 binary digits (bits) starting from the right.1. 001 001 011 110 101 Binary1 .   1    1     3      6       5 Octal • Binary to Hexadecimal Conversion : Binary Number 1001001011110101Split into groups of 4 bits starting from the right. 1001 0010 1111 0101 Binary    9      2      F      5   Hexadecimal • Decimal to Binary: Example:Convert 46(base 10) to binary. Divide the number successively by 2 and note the remainders (0 or 1). Write down these remainders, starting from the right and working left.46 / 2 rem 0                023 / 2 rem 1               1011 / 2 rem 1              110  5 / 2 rem 1            1110  2 / rem 0           01110  1 / 2 rem 1         101110  0 Binary                0101110 Haifaa Elayyan

26. Binary Addition • If a carry is generated, it is carried one position to the left as in decimal arithmetic. • Example: • Add binary numbers 101 and 111 •    101 +111 1100 • Starting from the rightmost column, 1 + 1 means that you write 0 and carry 1 to the next column on the left.Move to the left, add 0 + 1 plus the 1 you carried. Therefore you write 0 and carry 1 to the next column.Move to the left, add 1 + 1 plus the 1 that you carried. Therefore you write 1 and carry 1 to the next column.Move to the left, nothing to add other than the 1 you carried. Therefore the 1 is placed in front of the other 3 binary digits.Result 1100. Haifaa Elayyan

27. Computers as tools for finding • Computers can be used to find things and the obvious thing they can find is information. The World Wide Web (WWW or just the web) is just one example of a vast store of information which can be searched to find what you want using computers. But computers can also ‘find’ things in the sense of locating them geographically, either by generating maps that can be used for navigation or by locating something or someone with reference to a map. • This section aims to: • describe how computers can be used in geographical applications (and, • in doing so, it discusses maps and shows that maps can have uses beyond mere navigation); • describe and help you learn how to find information Haifaa Elayyan

28. Computers as tools for finding • Maps Many people are fascinated by maps, and most find them useful, though not in all situations. A lone driver, without a map-reading navigator, will find it difficult to use a map. New in-car navigation systems are designed to help such a driver, or one who is without map-reading skills but is able to follow directions. • Geographical data Modern maps are now mostly assembled by computers using very large collections of geographical data, such as latitude, longitude, altitude, roads and towns. Collections of data like this (stored in databases) aim to eliminate the need to duplicate data. The data in databases is described in symbols that the computer can handle, i.e. numbers. Even the names of features are symbolized using numbers. Haifaa Elayyan

29. Computers as tools for finding • Global positioning system (GPS) These days, it is possible to buy a device known as a global positioning system (GPS) to tell you where you are. Receivers are made for aircraft, ships, ground vehicles, and (as the one shown in Figure 4.3) for carrying in the hand. • Examples of applications for GPS are: • navigation; • surveying, and establishing the shortest distance between two points (a line of sight along the ground is no longer necessary for precise • positioning, so greater distances, with features such as hills obscuring the line of sight, can be surveyed much more easily); • plate tectonic studies (seeing how large areas of the earth’s surface move relative to each other). • The worldwide GPS is funded and controlled Haifaa Elayyan

30. Finding information: the web • The web is a vast storehouse of ever changing, linked information on subjects as diverse as dog breeding, astronomy, tiddlywinks, and coping with bereavement. • A browser, like Internet Explorer, is used to access the web. However, given that the web contains literally billions of words of text, how would you find information on, say, the Open University?. • The internet and the web: what’s the difference? • People sometimes confuse the internet and the World Wide Web. • The internet refers to the physical interconnection of large numbers of smaller data communications networks to form a huge, publicly accessible ‘network of networks’. Thus the internet carries electronic mail (email), hosts chat rooms and bulletin boards, enables the transfer of files, and is the physical basis for supporting the World Wide Web. The web is the collection of linked data stored on the internet which is accessed using a browser. Haifaa Elayyan

31. Search engines: what are they? • The computer application that facilitates finding things on the web is known as a search engine. This is an application that serves a similar function to an index in a book. Figure 4.6 shows the home page of a typical search engine called Google. Haifaa Elayyan

32. Search engines: what are they? • It is instructive to understand the steps involved when a web search engine is used; assume you have run your browser, invoked a search engine and chosen the keywords you are interested in. 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) but I have introduced some additional ideas here. n Computers can communicate with each other, and two or more computers can cooperate to provide a service to users. Some remote computer, the web server, contains data that the user, who could be anywhere in the world, wants to access. This web server Haifaa Elayyan