In software engineering, you typically have different types of requirements - functional and non-functional. Functional requirements are physical attributes/functions of the system/product - basically, what it does. Non-functional is how well it does this. For a mobile phone, a functional requirement may be that the phone allows users to store common numbers in an address book and a non-functional requirement may be that it can receive calls in 95% of urban requirements.Questionnaires are produced in a written format that requires very careful work (piloting and refining a questionnaire) to ensure that the questions are absolutely clear to all respondents and that you are collecting all the information you need.?