Revision

Revision

1. Valid data (normal data) - data that is correct, within range and of the right format. ■ Extreme data - data that is just on the edge of the valid range. ■ Invalid data - data that is not within the acceptable range or of an incorrect format. ■ Null data - when no data is entered to see what happens. ■ Erroneous data - data that of the wrong type altogether, for example entering 'Bob' instead of a numerical ID number.

2. Errors in software are often called bugs. ■ Bugs are mistakes - they are not deliberate attempts to bring down systems; they should not be confused with viruses and other malware. ■ The purpose of testing is to check that a program: ○ Works as intended under good conditions ○ Copes with errors when given bad data

3. Iterative testing involves testing code as it is written. The results of this continual testing feedback into the continued development of the solution. Final (or terminal) testing occurs at the end of development and is used to check how the software performs when given a predefined set of test data.