2.8 Computer errors
There are two main types of errors: program errors and data input errors.
Program errors result in incorrect results that may or may not be noticeable. Program testing will hopefully be rigorous enough to ensure that a program works properly before being let loose on the unsuspecting public.
Data input errors are a result of the data entry operator entering data incorrectly. For humans there is a saying ‘You are what you eat’. For computers, the corresponding saying is ‘Garbage in, garbage out’ or GIGO.
Even if the programs are near perfect, the worth of data processing results relies on the accurate input of data. Accurate data input should lead to accurate information output. For example, a customer pays for a $10 sale with a fifty dollar note. The salesperson can enter the cash tendered as shown below – one with the correct result – the other rubbish.
| Input | Sale total | 10.00 | 10.00 |
| Input | Cash tendered | 50.00 | 5000.00 |
| Display | Change required | 40.00 | 4990.00 |
Computer errors
- What does GIGO mean?
- There are often programs to automatically check for inaccurate data entry. However, vigilance and proofreading are still required to double check. Consider the following paragraph. The spelling is accurate, so what is the problem?
My pea sea has a spelling chequer. It marques sew eye can sea miss steaks. It shows strait a weigh weather eye am wrong oar write immediately a mist ache is maid, sew eye can put it rite. Rare lea ever wrong, its let her perfect awl the weigh sew I no I am write. - Write the paragraph above out correctly.