DataCollection Methods

Sekaran, Uma & Bougie, Roger (2010). Research Methods for Business – A Skill Building Approach (6th Ed.) use this book as one of the references (its a must)
In the essay answer the following questions:
1) what types of observations can you use in the data collection process?
2) Under which circumstances would you prefer observation vs personal interviews and questioning?
3) Disadvantages for observation bias (three types)
4)what are ethical disadvantages of undercover observation
the answers to these questions can be found in chapter 8 of the book given above