2.2 data and information

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2.2 data and information

  1. 1. INFO 2<br />Unit 2.2 Data and Information<br />
  2. 2. Specification<br />
  3. 3. What is Data?<br />What types of data are there?<br />What is a Bit<br />What is a Byte<br />What is a Kilobyte<br />To consolidate you should be able to answer these questions…<br />
  4. 4. 01001001011011100010000001110100011011110110010001100001011110011001001001110011001000000110110001100101011100110111001101101111011011100010000001110111011001010010000001100001011100100110010100100000011001110110111101101001011011100110011100100000011101000110111100100000011000110110111101101110011101000110100101101110011101010110010100100000011011000110010101100001011100100110111001101001011011100110011100100000011000010110001001101111011101010111010000100000011000100110100101101110011000010111001001111001<br />01001111011000100110101001100101011000110111010001101001011101100110010101110011<br />
  5. 5. In today’s lesson we are going to continue learning about binary<br />Objectives<br />
  6. 6. Data is raw facts and figures or a set of values, data has no meaning.<br />Examination Results (DATA) : 3312, 2, 35, 3, 64, 4421, 2, 48, 3, 56<br />Data is generated by an event e.g. Buying a product in a supermarket<br />Loyalty card number<br />Barcode number of each item bought<br />Weight of apples<br />Credit card number to pay for goods<br />What is Data?<br />
  7. 7. Data can arise in formats other than numbers and text<br />Text (Alphanumeric)<br />Number (Numeric)<br />Boolean<br />Audio<br />Image<br />Video<br />Whatever the type of data bring input, computers store and process data using binary numbers.<br />Types of data<br />
  8. 8. What is data capture?<br />Means the collection of data to enter into a computer<br />How can we enter data into a computer?<br />Keyboard<br />Speech recognition<br />Webcam <br />Touch screen<br />Scanner<br />Bar code reader<br />Sensors <br />How data can arise<br />
  9. 9. Direct Data Capture<br />Collection of data for a particular purpose<br />Direct Data Capture Methods<br />Bar Code Reader<br />MICR<br />OMR<br />OCR<br />Sensors<br />Direct and Indirect data capture<br />
  10. 10. Indirect Data Capture<br />Collection of data as a by-product from another purpose<br />Example<br />Using the data collected from reading barcodes at a super market till to work out stock levels<br />Direct and Indirect data capture<br />
  11. 11. GIGO<br />In ICT GIGO stands for Garbage In Garbage Out<br />It relates to Information only being as good as the data that is input<br />i.e. I put incorrect data into a system (accidently or deliberately) then the information that is output will be incorrect.<br />Use only a Pencil, one key colour and an A4 piece of paper to illustrate this Abbreviation and it’s meaning. Think about using a diagram, keywords and definitions to illustrate.<br />Activity<br />
  12. 12. Encoding is used by computers to convert the data into machine readable form i.e. binary<br />Encoding Data<br />
  13. 13. A single unit in binary is called a ‘bit’ (stands for binary digit)<br />Computer memory is measured in ‘bytes’<br />Onebyte is made up of eightbits<br />One byte can store one character e.g. the letter A is represented by 010000001<br />Binary Numbers<br />
  14. 14. One byte can store one character e.g. the letter A is represented by 010000001<br />Another variation of this byte can store another Character e.g. B is represented by 01000010<br />A byte has 256 variations of data it can store<br />Binary Numbers<br />
  15. 15. Protocols have been developed to standardize the conversion of this binary code to content we are familiar with.<br />ASCII is a standard that converts binary to character output<br />MP3 is a standard that converts binary to audio output<br />Protocols<br />
  16. 16. Illustration<br />Application<br />Standard<br />Output<br />Device<br />Standard<br />Output<br />M<br />ASCII<br />MP3<br />Binary 1 bite<br />01110010<br />Application<br />Standard<br />Output<br />Application<br />Standard<br />Output<br />PSD<br />WMV<br />
  17. 17. The American Standard Code for Information Interchange<br />Defines 128 characters (Requires only 7 bits of a byte)<br />ASCII<br />
  18. 18. We can work out the binary from the decimal and vice versa, the decimal from the binary<br />ASCII<br />
  19. 19. Binary to Decimal<br />Simply plot the 1’s under the necessary values e.g. if I want 67<br />ASCII<br />C<br />
  20. 20. ASCII<br />Decimal to Binary is a little trickier<br />Lets imagine you want to find the binary for decimal 116 (The letter t)<br />You must work your way through the table below<br />Can you take 128 from 116?NO (0)<br />Can you take 64 from 116?YES (1) you now have 52<br />Can you take 32 from 52?YES (1) you now have 20<br />Can you take 16 from 20?YES (1) you now have 4<br />Can you take 8 from 4?NO(0) you still have 4<br />Can you take 4 from 4?YES(1) you now have 0<br />Can you take 2 from 0?NO(0) you still have 0<br />Can you take 1 from 0?NO(0) you still have 0<br />0<br />1<br />1<br />1<br />0<br />1<br />0<br />0<br />
  21. 21. Use the two methods you have just learnt to convert the following:<br />Binary to Decimal<br />01001101 = <br />10011111 = <br />01100000 =<br />00010100 =<br />Decimal to Binary<br />48 = <br />239 = <br />110 = <br />17 =<br />Activity<br />
  22. 22. Use the two methods you have just learnt to convert the following:<br />Binary to Decimal<br />01001101 = 77<br />10011111 = 159<br />01100000 =96<br />00010100 = 20<br />Decimal to Binary<br />48 = 00110000<br />239 = 11101111<br />110 = 01101110<br />17 = 00010001<br />Activity<br />
  23. 23. Coding data is NOT the same as Encoding data<br />Data is coded to reduce data entry and reduce the need for storage space.<br />Imagine this scenario:<br />You are conducting 500,000 questionnaires<br />You ask each user to identify whether they are male or female<br />The largest response would be ‘female’ which contains 6 bytes of data<br />If all 500,000 users are female that means that the total storage for that one response will be:<br />3000,000 bytes<br />2929 Kilobytes<br />2.8 Megabytes<br />If you were to code this data by asking the user are you M/F<br />The largest response would be M or F which both contain only one byte<br />This would reduce the data storage to:<br />500,000 bytes<br />488 Kilobytes<br />0.47 Megabytes<br />Coding data<br />
  24. 24. Examples of data that are coded are:<br />Gender often asked as M or F<br />Bank sort codes are a number (60-55-63) instead of the name of the branch<br />Dates of Birth instead of 18th February 1981 it becomes 18/02/81<br />Destinations at Airports DXB, LHR etc.<br />Postcodes<br />Codes are used because:<br />Can be easier to remember (ISBN’s are not)<br />Usually short and quicker to enter (thus fewer errors are likely to be made)<br />Take up less storage space<br />Ensure consistency<br />Easier to check that the data is valid<br />Who codes data and why?<br />If the data is to become information it is likely that the data is decoded before it is output e.g. barcode (coded data) output information – total cost of product<br />
  25. 25. Loss of precision<br />Examples<br />How old are you?<br /> 12 – 15  16 – 18  19 – 23<br />How would you rate this school?<br />  Poor  Good  Very Good<br /> (Value judgement is required here also)<br />The colour of the article will be<br />Problems with coding data<br />
  26. 26. What is Processing?<br />It is the work the computer does on the data to convert it into information e.g. searching, calculating, sorting etc.<br />Processing<br />
  27. 27. What is information?<br />Information is data that has been processed, put into context and given a meaning. It must be understandable to the user.<br />Information<br />
  28. 28. Information is good quality if it is:<br />Accurate<br />Up-to-date<br />Complete<br />From a reliable source<br />Relevant<br />Quality of information<br />
  29. 29. How accurate will depend upon its use:<br />Bank statement details should be exact to the penny<br />Whole School A Level pass rates at a school might be to the nearest 1% (This would be sufficient)<br />Imagine inaccurate information relating to stock figures this could result in products not being available to customers or an over order resulting in to much stock to store.<br />Thorough error checking and regular up dates must take place to ensure the information is as accurate as possible<br />Accurate Information<br />http://news.bbc.co.uk/2/hi/8176957.stm<br />
  30. 30. Some information only has value within a specific time scale e.g. share prices.<br />If information is out of date wrong decisions could be made. For example:<br />An employee of a cinema taking a booking for the evening performance needs to know which seats are available at the time of booking not the ones available at the start of the day.<br />Reports should contain dates and where possible times<br />Keeping data up-to-date effects the costs<br />Use to be batch processing now transaction processing<br />Up-To-Date Information<br />
  31. 31. If information is incomplete it loses its value and can misinform. <br />If you collect details about a householder for insurance purposes and don’t request information about the value of the house, the house might be insured for the wrong value.<br />If you conduct a survey and half of the questions are not answered your analysis of those results could be inaccurate.<br />Complete Information<br />http://www.bbc.co.uk/news/business-10701953<br />
  32. 32. The internet offers a huge range of information. However, the internet is not governed, thus no one controls the content.<br />Consider Wikipedia, it is an open source network that allows anyone who is registered to add content. There are editors who are able to check the validity but only to the extent of their knowledge base.<br />Trusted sites like .gov .ae, BBC are recommended<br />Information from a reliable source<br />
  33. 33. Information is only valuable to someone who has use for it and its value will depend on its potential use.<br />Relevant<br />Obama’s views on the value of information, is it just a distraction?<br />http://tek.io/hwJAiP<br />
  34. 34. Global Positioning Systems (GPS)<br />Are able to provide drivers with accurate, relevant and Up-to-Date Information<br />GPS<br />
  35. 35. How does social media impact the quality and value of information?<br />Consider this Cairo activists comments:<br /> “We use Facebook to schedule the protests, Twitter to coordinate, and YouTube to tell the world."<br />Discussion<br />http://www.bbc.co.uk/news/world-africa-12289475<br />
  36. 36. Past Paper Questions<br />
  37. 37. Past Paper Questions<br />
  38. 38. Past Paper Questions<br />
  39. 39. Past Paper Questions<br />
  40. 40. Past Paper Questions<br />

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