In this section you should be able to:
The Data, Information, & Knowledge Relationship
Click each arrow for more details
Introduction to Computer Systems:
Data can captured (entered) directly into a computer system or entered indirectly, usually via a keyboard, for example:
|Direct data capture||Indirect data entry|
|Bar code reader, e.g. scanning goods bought at a supermarket||Typing pupil's homework marks into a spreadsheet|
|Optical character reader, e.g. school registers||Typing customers' details into a database|
|MICR - magnetic ink character recognition - used to automatically read a cheque's sort code and account number||Entering hours worked by employees into a wages system|
|Data logging, e.g. automatic weather station collecting temperature data||Reading temperature from a thermometer and typing value into a spreadsheet|
Mistakes in entering data will result in problems with the information produced, e.g.
Problem Data - Garbage in
Result - Garbage out
|Numbers transposed (swapped around) on an order form, e.g. 75 instead of 57||Correct product sent, but what customer wanted|
|Number mis-read when data entered, e.g. gas meter reading entered as 5 instead of 8||Smaller bill sent to customer, gas company not paid correctly for gas used|
|Number entered twice. e.g. 44 items bought instead of 4||Customer overcharged for goods|
|Extra numbers added, e.g. 100 hours worked instead of 10||Employee overpaid for hours worked|
|Correct data entered for wrong item, e.g. Customer A's details entered with address of Customer B||Customer A does not recieve goods or invoices. Customer B recieve wrong goods and invoices.|
|Incorrect data selected, e.g. student ticks the wrong box or the wrong item chosen from a drop down menu||Student registered for subjects they do not want to study|
There are two main methods that are used to ensure, where possible, that the data entered into an computer information system is correct.
Do you know how each method can be used?
Data (text and numbers) are stored in a computer system in binary form, which is often represented as 0s and 1s, e.g.
Coding data before it is entered into a computer system has many advantages:
|Information or data||Code|
|Gender||M = male, F= female|
|Date||01/01/2006 = 1st January 2006|
|Post code||BD1 = Bradford, city centre area|
|Branches of high street banks||Sort code, e.g. 60-18-46|
|Airport||LHR = London Heathrow|
Now do the questions at the end of Chapter 8 of the text book