You're a big company. Imagine you had a simple user interface built into the coffee machine in your workplace's kitchens. You can ask every employee a question or two every day (and they'll answers). What would you ask?
I would ask open ended questions to get them really talking like:
1. How can we improve your work environment?
2. What do you find can be improved with our medical benefits?
3. What other job tasks would you be interested in performing for your role here?
Open ended questions are questions that are not answered with one word like "yes", "no", "maybe". Make employees open up, hence "open ended questions".
Bruce