It refers to entering the data into the system. Data can be entered by a variety of methods:
- A keyboard to manually type in the data
- A mouse to select from a list of options
- Scanning a barcode
- Using an optical mark reader
Examples of input data could include:
- Data collected by a temperature sensor being automatically input into a central heating system.
- Student grades from a piece of homework being entered into a teacher’s electronic notebook.
- Lottery ticket numbers being ‘fed’ into an OMR which then enters them into the National Lottery system.
It is the stage where the input data is manipulated in order to produce meaningful information. Processing can include a number of stages such as sorting, searching, calculations, graphing.
Some examples of processing could include:
- Searching sales data to find which products in a supermarket have sold the most.
- Sorting a list of customer data into alphabetical order.
- After a barcode has been scanned, retrieving the price of the item from the supermarket database and using this data to calculate the customer’s bill.
It is the stage where the information obtained via processing is presented to the user in a suitable format.
Examples of output could include:
- A printout of student examination results displayed in order from highest to lowest.
- A digital display at the petrol pump showing how much fuel has been delivered and the cost of that fuel.
- An alarm from a fire alarm system which has detected smoke in the room.
Feedback is where the output from a system is fed back into the system in order to influence the input.
Example: when you try to withdraw too much money from your account at an ATM a warning on the screen will advise you that it isn’t possible and will suggest that you try to withdraw a smaller amount.