Course Information. Course Name: M150-A [Data, Computing and Information] Course Material and resources

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1 The contents of this Supporting Material document have been prepared from the Eight units of study texts for the course M150: Date, Computing and Information, produced by The Open University, UK. Copyright The Open University, UK. Course Information Course Name: M150-A [Data, Computing and Information] 4 credits, one semester. Lectures are biweekly. Assessment: 1 TMA (20%) 1 MTA (30%) Final exam (50%) Course Material and resources Block 1: Unit1, 2 and 3. Block 2: Unit 6, 7 and 8 (section 2). 1

2 This course is about: Introduction 1. Data: A discrete item, such as a person s name, the price, or the number of a bus route. Human sensations form the most primitive kind of data. 2. Computers and how they can be made to work with data. Computer: A form of tool for storing, processing and analyzing data to turn it into information. 3. Information: An item of knowledge that is generated by linking together items of data to answer questions of interest. Introduction This course aims to: Explain why people use computers; Demonstrate that computers do more than just process data: they collect, store and display it in different forms; Help you make more effective use of your computer; Teach you how to program; Investigate the importance of information to human beings, and show how the way it s presented can be as important as its content; Examine how computers can be used to keep track of people, and how political, legal and ethical issues arise from this; Examine the limitations of computers, data and information; Provide you with study skills, such as information finding, and transferable skills. 2

3 Sensing data and turning it into something usable Data refers to discrete items, such as your name, the price of an item on the shelf of a supermarket. Information involves linking together two or more items of data to provide an item of knowledge. For example: The price of a liter of milk is 50p, would convey information. We live in a sea of sensation: sight, sound, touch, taste, smell and balance. 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. Sensing data and turning it into something usable Humans invented computers because we have a compelling interest in data, and the information we can derive from it. Modern computers, with their enormous storage capacity and incredible processing power, are an ideal tool for storing, analyzing, and processing data, and then turning them into information. In the coming sections we are going to see how computers are important for human activities, they are tools for: Finding information and things; Working with data; Controlling machines; Selling. 3

4 Computers can be used to find things and information. Computers can also find things in the sense of locating them geographically, either by: Generating maps that can be used for navigation. Locating something or someone with reference to a map (GPS). 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. Maps can be made up of separate layers of data: 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. 4

5 The two maps below show two different types of maps. Both cover approximately the same area but look very different. They are for a similar purpose (longer distance travel) but serve completely different audiences. Global positioning system (GPS) is a U.S. space-based global navigation satellite system. It provides reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the Earth. GPS is made up of three parts: between 24 and 32 satellites orbiting the Earth, four control and monitoring stations on Earth, and the GPS receivers owned by users. GPS satellites broadcast signals from space that are used by GPS receivers to provide three-dimensional location (latitude, longitude, and altitude) plus the time. Examples of applications for GPS are: Navigation; Surveying, and establishing the shortest distance between two points. Plate tectonic studies land surveying (seeing how large areas of the earth s surface move relative to each other). 5

6 The internet refers to the physical interconnection of large numbers of communications networks to form a huge, publicly accessible network of networks. The web is the collection of linked data stored on the internet which is accessed using a browser. A search engine is a computer application that facilitates finding information on a particular topic on the web. It serves the same function for the web as an index serves for a book. Google, Yahoo and Lycos are examples on web search engines. Different search engines gives slightly different results to the same search. What happens when you type a keyword in a search engine? 1. The keywords are transmitted over the internet to a special computer known as a web server which 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 (using a computer program) 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. 6

7 Gateway is a website intended to direct users to other, pre-selected, websites containing information on a particular topic (often created by librarians, professional societies, and other concerned groups). 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. Computers as 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 nonexpert. 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. 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. 7

8 Computers as tools for working with data 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. Controlling things; selling things Most household appliance, such as the automatic washing machine, are controlled using a microcomputer. The role of computer control systems in many mechanical devices is: They manage sensors and actuators to control the actions of mechanical devices such as cars, microwaves and washing machines. They provide interfaces that enable the user to control the workings of the machine. They control the machine s actions in response to the user s choices and the state of the machine. 8

9 Controlling things; selling things Computers are used to support selling goods and services via the web. Web-based selling seems to be concentrated in three main categories of company: 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. This is the most successful category financially. Example, Pergamon Press, which publishes many professional journals, has moved to making all its journals available electronically. Hence, selling and distribution is done over the web. Most subscribers have chosen to use the convenience of electronic delivery, and this has drastically reduced printing, warehousing and distribution costs for Pergamon. 3. Companies which have started from scratch using the web as their only sales medium. Example: online bookseller, Amazon. Amazon has recently expanded into all kinds of consumer goods such as smaller electronics, videos and DVDs. It also acts as an agent for sales of second-hand goods. Controlling things; selling things Computers are used to support selling goods and services via the web. Many people don t shop on the web because they fear about the stolen of their credit card details or that they ll start getting junk mails after they provide their names and addresses to a firm on the web. To be more confident of buying from the web: 1. Deal only with web sellers you know are reputable. 2. 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. 9

10 Unit Summary The unit explored some basic issues involving computers: The nature of data and information. Why human beings need (and want) computers. The prevalence of computers in modern life. What computers can do with data to produce information. How computers can be used to work with data and search for it, control machines, and support commercial operations. 10