2.3

• Maintainability: 


  Use of sub programs

  Naming variables

  Indentation

  Commenting
• Defensive design considerations: 


  Anticipating misuse

  Authentication
• Normal test data 


  Data which should be accepted by a program without causing errors
• Boundary test data 


  Data of the correct type which is on the very edge of being valid
• Invalid test data 


  Data of the correct data type which should be rejected by a computer system
• Erroneous test data

  Data of the incorrect data type which should be rejected by a computer system
• Iterative testing is testing modules of a program during development.
• Terminal testing is testing the program at the end of production.