Final answer:
A good practice for creating a questionnaire is to include both closed-ended and open-ended questions.
Step-by-step explanation:
A good practice for creating a questionnaire is to use a combination of closed-ended and open-ended questions. Closed-ended questions, such as yes-or-no or multiple-choice questions, provide quantitative data that can be counted and analyzed. Open-ended questions, on the other hand, allow for subjective responses that provide qualitative data. By including both types of questions, researchers can gather a range of information that is both numerical and personal.