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M150: Data, Computing and Information. Unit one: Data and information: an introduction. 1- Introduction. Aims of this unit: Using case studies that relate the use of computers to finding, storing, processing and disseminating data and information;
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M150: Data, Computing and Information Unit one: Data and information: an introduction
1- Introduction Aims of this unit: Using case studies that relate the use of computers to finding, storing, processing and disseminating data and information; Describing various instances of computer use to see how computers can work with data to produce information; Introducing you to what a browser is, and how to use it Demonstrating how to use a search engine to find information more effectively.
1- Introduction Most people experience computers not only as a remote machines producing bills or directing space flight, but also its used as medium that combines graphics, video, sound and text to impart information and a means of enabling us to shop on the internet, and also to controlling everything. We are use Computers in our daily lives, but many of them are invisible to us Individual activities: Radio- alarm Cooker Car (control the steering, manage the engine, control the braking system , navigation system) Write material using computer, send and receive emails Bank (automated teller machine or ATM) Mobile telephone Supermarkets (order items)
2- Daily life and computers • Two words are used in connection with computers: • Data: refers to discrete items, such as person’s name, the price of an item, or the type of product. • Information: involves linking together two or more items of data to provide an item of knowledge (Information can be thought of as the answer to a question) • For example: ‘The price of a liter of milk is 50’, would convey information
3- Sensing data and turning it into something usable We live in a sea of sensation: sight, sound, touch, taste and smell Transform sensation into appropriate form If you touch a surface, one of the things you will sense is its temperature We have developed words like ‘hot’, ‘cold’, ‘warm’, and ‘cool’ Such words allow us to link one sensation (touch) to another (vision) We have developed more objective measures of hot and cold, such as the length of a column of mercury in a thermometer. Perceptual data : what we perceive with our senses (primitive form of data)
3- Sensing data and turning it into something usable A sign or symbol is a way of representing data. 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: that symbolize something. Beeping sound (audible signs) Road traffic (visual sign) Flags Legends on maps Braille (tactile sign): which is intended to be read by those with a visual impairment using the tips of the fingers Words are also a signs (name is a sign)
3- Sensing data and turning it into something usable Data and information: 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. Example: Recipe for making a cake
3- Sensing data and turning it into something usable What has any of this to do with computers Computers can mimic our senses and gather data we have no way of dealing with directly (Example: photographs from space) Modern computer systems with their incredible capabilities enable us to sense, store, process, transmit and display data in ways that were previously unimaginable The information that computers produce can be used to control devices like mechanical or hydraulic machinery. (which can be dangerous for humans to operate)
3- Sensing data and turning it into something usable • Computers have vast memories. Once such data is stored, we do not need to remember it: rather we can concentrate on remembering what it describes and where it can be found. • A computer system is the combination of: • The computer (with its processor and storage) • Other equipment such as a scanner or printer • The software programs that make it all work • In the coming sections we are doing to see how computers are tools for: • Sensing data and turning it into something usable • Finding information and things • Working with data • Controlling machines • Selling
4- Computers as tools for finding • Computers can be used to find information. (World Wide Web “WWW”). • Also computers can be used to find things in the sense of locating them geographically (maps, navigation system). • The role of the computer is to transform data into information. • The presentation of information needs to be fit-for-purpose (the form of presentation depends on the requirements of the user or the situation in which the information is needed).
4- Computers as tools for finding Maps A map can be made up of separate layers of data (Maps Layers): Maps use latitude and longitude to form a two dimensional grid. Contour lines give an idea of the topography of the area (altitude). Features such as rivers, roads, buildings and boundaries; The names of towns, roads, hills, rivers and other notable features of the landscape.
4- Computers as tools for finding Geographical data Stored in databases (collections of data) Leave out some layers for a particular purpose Global positioning system (GPS) Is used to tell you where you are. (aircraft, ships, cars) Examples of applications for GPS are: Navigation Surveying and establishing the shortest distance between two points land surveying -Seeing how large areas of the earth’s surface move relative to each other What happens when a map is wholly inappropriate (navigating in the dark, smoke or fog, or if the user has a visual impairment) give audible directions
4- Computers as tools for finding Finding information: the web A browser, like Internet Explorer, is used to access web Different between web and internet 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 email, hosts chat rooms, 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
4- Computers as tools for finding Finding information: the web Search engines The computer application that facilitates finding things on the web Single box waiting the keyword Serves a similar function to an index in a book Example: Google, Yahoo, Lycos, … Different search engines gives slightly different results to the same search. Ego surfing: The term surfing, refers to the process of wandering around the web searching for information. The term ego surfing describes the act of looking for information about oneself
4- Computers as tools for finding Finding information: the web The process: The keywords are transmitted over the internet to a web server that contains an index to websites which is associated with a series of keywords that 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. 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. The browser then displays the references for the user.
4- Computers as tools for finding Finding information: the web Using the web more effectively: the gateways A gateway on the web is a website intended to direct users to other preselected websites containing information on a particular topic. It provides a pre-chosen set of links on the web for a particular topic Instead of searching the whole of the web for information, a gateway provides a very focused means of getting information. Many gateway sites are searchable, often using the same search engines (e.g. Google) that are available directly through browsers. Using a search engine more effectively One of the problems with finding information on the web is that there is so much, and not all of it is relevant to what you want. You can solve the problem by: Looking for phrases rather than individual words. Use a selectable topic like Advanced Search or Search Tips. Choose keywords carefully.
5- Computers as tools for working with data Computer program is a set of instructions that tell the computer what to do. The computer and its programs are tools for working with data. The computer can be used as an artist’s tool Complex data, such as the graphical representation of a scene, can be made relatively easy to use by a non-expert. Computers can be used by artists to produce art using the right sort of program and appropriate peripheral devices. Photograph and painting are very complex. Contain infinite colors spectrum, light and shade, lines and edges, and visual depth.
5- Computers as tools for working with data Applications for processing graphical take care of this complexity. They let the user work with graphical data at higher levels of abstraction, such as deepening a color's hue, altering the contrast, and so on. The main advantages of the computer as an artist’s tool are: It is possible to make many copies of something. This enables the artist to experiment freely, throwing away mistakes or results that don’t please, or making many different versions from a single original. Produce effects that would be difficult using traditional media.
6- Controlling things; selling things Computers can collect, process, store and distribute information (as you mention previously). They can also control machines and selling on the web. Controlling things Automatic washing machine or microwave contains microcomputer. The main tasks of a microcomputer: Present an interface to the users Displaying the choices Displaying indications Allow the user to choose programs and parameters Ensure safe operation of the machine such as preventing the user making choices that are not sensible. Controlling the machine. To do this, the computer is electrically attached to a variety of: Actuators that cause mechanical parts of the system to work Sensors that sense the state of some aspect of the machine, such as water temperature and laundry weight
6- Controlling things; selling things Selling on the web The web is a medium for selling everything from books to clothes, beauty products, investment advice to travel services Three main categories of company in Web based selling: 1. Existing catalogue sales companies which have put their catalogues online to allow customers to buy using the web. Example: Lakeland, a British company 2. 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; (Professional Journals) This is the most successful category financially Example: Pergamon Press, which publishes many professional journals, has moved to making all its journal available electronically. Hence, selling and distribution is done over the web 3. Companies which have started from scratch using the web as their only sales medium. Example: Online bookseller (Amazon) The most successful financially have been those in the second category
6- Controlling things; selling things Selling on the web Browse through the details of the goods for sale Search for a particular product Check the availability of goods Read and review the comment of other purchasers Register to receive newsletters Buy product using credit or debit cards See what items are most popular
6- Controlling things; selling things To be able to search a selling website requires not only a web server but a database server. Database servers 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 Distributed system means that separate computers exchange data and information across a network (in this case the internet) to produce results for a user. The parts of distributed system are: The web server The database server
6- Controlling things; selling things Many people don’t shop on the web because they fear about stolen of their credit card details or that they will getting junk mail after they provide their names and addresses to a firm on the web. You can be reasonably confident of buying from a website if it displays one of two things (Security) Deal only with web sellers you know are reputable. Make sure that these sites are connected to a secure web server which uses techniques to protect customers’ details from electronic snoopers. This is indicated by Address shown in the bar at the top of the screen should start with ‘https’ instead of ‘http’. The letter ‘s’ means you are connected to a secure web server using techniques to protect your details from electronic snoopers. An icon representing a small key is present. This also indicates that the web server you are connected to is a secure one.
