Questionnaire

• • Questionnaires are like written interviews, done face-to-face, by phone, or by post. Questions must avoid bias, ambiguity, and offense. 

   
• • Open questions: Encourage detailed answers, providing insights into feelings and opinions (e.g., "How do you feel about that situation?"). 

   
• • Closed questions: Simple answers (e.g., "yes" or "no"), useful for gathering specific facts (e.g., "Do you feel anxious in crowds?"). 
•  

  • Postal questionnaires: Reduce interview bias, are cheaper, and can reach many respondents quickly over a wide area.