The following links should help users get a good idea of how to conduct a scientific observation:
How to Conduct User Observations
https://www.interaction-design.org/literature/article/how-to-conduct-user-observations
Naturalistic Observation-Films on Demand Database (will need to log in using Moodle user name & password)
Participant Observation-Films on Demand Database (will need to log in using Moodle user name & password)