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