SECTION 5: SECTION 5: INFORMATION INFORMATION PROCESSINGPROCESSING

Distinguish between data Distinguish between data and and information; information; Data is a set of raw facts and

figures while information is processed data, that

is meaningful to the person who

receiving it

explain the characteristics explain the characteristics and and functions of Information functions of Information ProcessingProcessingInformation Processing is when a

machine or processor interacts with the

outside world and acts on the input it

receives.

Examples of information Examples of information processingprocessingPayroll- A payroll system used an information

processing system to calculate the wages of each employee, print out pay slips and record the information for accounting purposes.

Input: Comes from a database of employees details, such as salaries, pay rates, bonus rates

Process: Using software like spreadsheet or other

accounting software to calculate the amount earned by

employees.

Output: Pay slips would need to be printed using an impact.

Library- This is automated, where a membership card is issued which has barcode printed on it.

Input: Barcode from book, membership card, burrow date, librarians name etc

Process: Library database would have the files containing details about the books, magazines

etc.

Information Retrieval: Searches would have to be

performed on database by the librarian

Output: Summary reports results of searches

Industry: The whole manufacturing process is

controlled automatically by a computer system.

Input: Sensors take readings at regular time intervals and send the readings to the computer.

Processing: The computer analyzes the readings and decides whether action needed to be taken.

Output: The computer sends output signals to

devices which manage the process to increase

pressure or temperature.

Weather Forecasting: Some of the world’s most powerful computers are used to forecast the

weather, which improves the accuracy of forecasts.

Input: Millions of pieces of data such as temperature,

pressure etc are collected from satellites, radar etc.

Processing: The data is then stored in a large database.

The first task is to perform a quality control check.

Output: The forecasts are normally produced as global

and local charts of weather information.

Supermarket Stock Control: Businesses need to hold stocks of goods, they sell and manufacturers

need to hold their stock of raw materials and finished goods.

Input: the operator at a POS terminal only needs to pass the barcode on each item past a laser scanner.

Process: As each item is sold, the stock files are updated so that customer service can be much quicker

Output: Orders are printed when stock levels reach a

re-order point. Customer receipts are printed using thermal printers

Identify the sources of data in specified Identify the sources of data in specified application areas;application areas;

Turnaround document: A document which, after being output by the computer, can be used to record data.

An example of a turnaround document is the mark sheet that is filled in by your teacher. The mark sheet is generated by the computer, filled in by the subject teacher and then used for input back into the computer so that reports can be printed.

Human Readable: Data that can be understood by humans. Printers and

monitors produce human- readable copies.

Machine Readable: Data that can be

understood by computers. Disc drives and tape drives produce machine-readable copies.

Describe methods of Describe methods of validation andvalidation andverification of data;verification of data;

Validation : A checking process in a program

which is aimed at finding out if data is genuine. E.g The data type is text and Mr Jones gets typed in as Mr J0nes,

Verification: Is the checking for mistakes such as transcription errors when data is copied from one medium or device to

another.

Range Check: Range check ensures that the data entered is within a certain range. is a date in August between 1 and 31?

Data type checks: This is known as character or alphanumeric check. Whenever

data is entered into a field the database will Check that it is of the correct type.e.g. have letters been entered instead of

digits?

Inconsistency check: A consistency check compares the contents of two or more fields to make sure that they make sense.Transposition errors – happen when

we enter numbers or characters in the wrong order.

e.g. I wnet down the street and was my friends playing cricket.

Describe various methods of file Describe various methods of file organization and access;organization and access;

Direct access - This is where any data can be accessed without reading any other data items first (randomly). Examples: floppy diskette, flash drive, hard disk drive, etc.

Serial access - This is where all data between the read/write head and the required data have to be passed over before the data can be accessed.

An indexed file is used to speed up the

key search in a file. You can think of it as a

one column table.