What is the difference between qualitative and quantitative approaches to studying behavior?

What is the difference between qualitative and quantitative approaches to studying behavior?
What is naturalistic observation? How does a researcher collect data when conducting naturalistic observation research?
Why are the data in naturalistic observation research primarily qualitative?
Distinguish between participant and nonparticipant observation; between concealed and nonconcealed observation.
What is systematic observation? Why are the data from systematic observation primarily quantitative?
What is a coding system? What are some important considerations when developing a coding system?
What is a case study? When are case studies used? What is a psychobiography?
What is archival research? What are the major sources of archival data?
What is content analysis?