2.2 data and information

1. INFO 2
Unit 2.2 Data and Information

2. Specification
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
4. 01001001011011100010000001110100011011110110010001100001011110011001001001110011001000000110110001100101011100110111001101101111011011100010000001110111011001010010000001100001011100100110010100100000011001110110111101101001011011100110011100100000011101000110111100100000011000110110111101101110011101000110100101101110011101010110010100100000011011000110010101100001011100100110111001101001011011100110011100100000011000010110001001101111011101010111010000100000011000100110100101101110011000010111001001111001
01001111011000100110101001100101011000110111010001101001011101100110010101110011
5. In todays 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 its 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. TheAmerican 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 1s 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 8 from 4?NO(0) you still have 4
Can you take 4 from 4?YES(1) you now 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 (ISBNs 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 dont 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
Obamas 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 tocoordinate, and YouTubeto tell the world."
Discussion
http://www.bbc.co.uk/news/world-africa-12289475
36. Past Paper Questions

Education

2.2 data and information