When conducting interviews why is it critical to develop specific interview questions?

TOPIC REMINDER: Liberty House Counseling Services Decline After Departure…refer back to the thesis statement
DISCUSSION QUESTIONS:
What is the difference between qualitative and quantitative research?
Given the topic you have chosen to study and assuming you were going to use a qualitative approach, which of the five designs (case, ethnography, phenomenological, grounded theory or content analysis) would be best suited to answer your research questions? Explain your decision.
Review the approaches discussed in your text for collecting quantitative data and determine which(sampling, observation, or interview) might be best suited for your study. Explain your decision.
When conducting interviews why is it critical to develop specific interview questions?
Is it useful to include scaled questions (e.g., Likert scale such as 1 to 5) as part of your structured interview questions? Why or why not?
Should open-ended questions be included? Why or why not?
What are useful data sources for conducting historical research?