Final answer:
When developing a marketing research questionnaire, you should avoid leading or biased questions, using jargon or complex language, and making the questionnaire too long.
Step-by-step explanation:
When developing a marketing research questionnaire, one thing you should avoid is leading or biased questions. These are questions that steer respondents towards a certain answer or have built-in assumptions that may influence their responses. For example, asking 'Don't you agree that our product is the best in the market?' assumes that the product is indeed the best, which may bias respondents' answers.
Another thing to avoid is using jargon or complex language in the questions. The questions should be clear, simple, and easily understandable by the target audience. Using technical terms or complex language may confuse respondents and lead to inaccurate or incomplete answers.
Lastly, it is important to avoid having too many questions or making the questionnaire too long. Respondents may become fatigued or lose interest, resulting in incomplete or less thoughtful responses. Keeping the questionnaire concise and focused on the most important information will increase the likelihood of obtaining accurate and valuable data.