Think about how you might alter the scene being observed.
Will you participate in the event?
Will you interact with the people around you?
How will you record what you observe?
Should you give the people involved time to adjust to your presence?
Driscoll, D. L. & Brizee, A. "Observing." Purdue Online Writing Lab. Purdue University. Web. 7 December 2015. https://owl.english.purdue.edu/owl/resource/559/07/