Which of the following is not a way to collect data?

The correct answer is option 2: Pilot Survey

There are three basic ways of collecting data: (i) Personal Interviews, (ii) Mailing (questionnaire) Surveys, and (iii) Telephone Interviews.

Pilot Survey is pre-testing of questionnaire. It helps in pre-testing of the questionnaire, so as to know the shortcomings and drawbacks of the questions. Pilot survey also helps in assessing the suitability of questions, clarity of instructions, performance of enumerators and the cost and time involved in the actual survey