Preparation Of Instrument

The most common survey instrument is the questionnaire (also called an interview schedule). It may be self-administered — filled in by the respondent alone — or administered by the researcher, an enumerator or a trained investigator who reads out the questions.

Good questionnaire design follows several rules:

• Keep it short. Use as few questions as possible.
• Keep it clear. Avoid ambiguous or difficult words.
• Order the questions comfortably, moving from general to specific. Ask the general question ("Is the electricity supply in your locality regular?") before the specific one ("Is the increase in electricity charges justified?").
• Be precise. Ask "What percentage of your income do you spend on clothing?" rather than loading it with extra words like "in order to look presentable".
• Avoid ambiguity so answers come quickly and correctly — instead of "Do you spend a lot of money on books?", give measured options (Less than Rs 200 / Rs 200–300 / Rs 300–400 / More than Rs 400).
• Avoid double negatives — "Do you think smoking should be prohibited?" not "Don't you think smoking should be prohibited?", since the latter biases the reply.
• Avoid leading questions that hint at the desired answer — "How do you like the flavour of this tea?" not "...this high-quality tea?".
• Do not suggest the alternatives — "What would you like to do after college?" rather than "Would you like to do a job after college or be a housewife?". …