Data Handling Topic 1

Data Data is the raw material entered into a computer system. This raw material could be text, numbers, graphics, audio, animation or video It is unorganised facts that mean little by themselves Eg: 1 Year Trivial fact: datum = single item of data data* = plural of datum * [commonly used and is accepted as both the singular and plural forms of the word]

Information When data is given a structure and put into context it becomes information a word processed document that we can read and understand A computer interprets and executes instructions to process the data into information Eg: Today + will + be + temperature + hot + a day + a + with + degrees + of Today will be a hot day with a temperature of 32 degrees

Classifying data as information is not always clear and absolute. What is information to one person may be data to another person. Information is a vital tool. Organisations cannot exist without it’s data/information. ‘the more information the better’ – only if the information is suitable, accurate, timely and reliable

Data Coding

Analog Analog data is represented by using continuous signals [wave form] that vary in strength and quality. Eg: an analog clock Because the movement is continuous, a measurement may be taken at any time. Eg: Human speech People combine words into sentences which are continuous

Digital Computers are digital They recognize two states: off and on Digital data is represented using discreet measurements in the form of digits/numbers – 0 & 1 The two digits [0 & 1] represent these two states 0 represents the electronic state of off 1 represents the electronic state of on Eg: a digital clock Shows the time as a certain number of hours and minutes. Time does not change continuously, but in a series of steps, jumping from second to second and minute to minute.

Binary A digit is a single place that can hold numerical values between 0 and 9 - base-10 number system – known as decimal number system. Computers happen to operate using the base-2 number system, also known as the binary number system. Why base-2? Because it makes it a lot easier to perform with current electronic technology.

Binary Technology uses a binary system that has just two unique digits – 0 & 1 Each digit is called a bit (Binary digIT) A bit is the smallest unit of data that a computer can process On it’s own a bit is not very informative When 8 bits are grouped together as a unit, they form a byte. A byte provides enough different combinations of 0s and 1s to represent 256 individual characters.

Units of Measurement

Binary How do you figure out what the value of a binary number is? You do it in the same way you would for a decimal number, but you use a base of 2 instead of a base of 10. Decimal [6,357]: (6 * 10^3) + (3 * 10^2) + (5 * 10^1) + (7 * 10^0) = = 6357 Binary number [11]: (1 * 2^3) + (0 * 2^2) + (1 * 2^1) + (1 * 2^0) = = 11 You can see that in binary numbers, each bit holds the value of increasing powers of 2.

Convert binary to decimal

Convert decimal to binary

Data Types

Numeric Text Hypertext Audiovisual Physical

Numeric Consists of numbers and decimal points. Both arithmetic operations (+ - * /) and logical operations (and, or, if, not) are performed on numeric data. Numbers can be used for calculations as well as sorted and compared to each other. A common file extension for numeric data include:.xls (spreadsheet)

Text Can contain any combination of letters, numbers and special characters. Sometimes textual data is known as alphanumeric data. Text is organised into words, sentences and paragraphs. Some common file extensions for text include:.doc (document).txt (text).rtf (rich text format) Essays, reports, letters, s are examples of textual data.

Hypertext Text displayed on a computer or other electronic device with references (hyperlinks) to other text that the reader/user can immediately access, usually by a mouse click Some file extensions for hypertext include:.html.htm

Audiovisual Various forms of data that we can hear or see Data takes the form of graphs, drawings, photographs, video sequences and sound.

Audiovisual - graphics There are two types of graphics Bitmapped graphics Each image is a pattern or map of tightly packed dots (ie bits) Each dot [a pixel – picture element] has a separate memory position that is represented by a colour or shade of grey when you enlarge a bitmapped graphic, you enlarge each pixel creating a staircase pattern called aliasing or “pixelated” e.g. photographs Most images on your computer are composed of bitmaps Vector graphics Not made up of a grid of pixels Allows continuous lines to be drawn comprised of paths which are defined by a start and end point Graphics are stored as mathematical formulas These graphics can be scaled to a large size and not lose any image quality

Audiovisual - graphics Common bitmap file extensions are:.bmp - bitmap.jpeg- Joint Photographic Experts Group.gif - Graphics Interchange Format.tif - Tagged Image File Common vector file extensions are:.ai – Adobe Illustrator.eps – Encapsulated PostScript file.svg – Scalable Vector Graphics file.drw – Drawing file

Audiovisual - audio An electrical representation of sound which can be transmitted or reproduced Common file extensions include:.mp3.wav.midi

Audiovisual Video and Animation Video The technology of electronically capturing, recording, processing, storing, transmitting and reconstructing a sequence of still images representing scenes in motion Animation The rapid display of a sequence of images of 2-D or 3- D artwork or model positions in order to create an illusion of movement. Common file formats for video include:.mpg,.mov Common file formats for animation include:.swf,.gif

Physical Captured from the environment. Light, temperature and pressure The temperature of a room may be controlled by a computer A thermostat is set to sense the air temperature. When the temperature exceeds a specified level, a cooling system is turned on. The warmth of the air is used as physical data input into a thermostat to regulate room temperature.