Answer:
naturalistic observation
Explanation:
According to my research on different research methodology, I can say that based on the information provided within the question Dr. Rajiv employed a naturalistic observation. This is a research method in which the researcher observes a subject in his/her natural environment without interference from the researcher or any third party that may affect the results.
I hope this answered your question. If you have any more questions feel free to ask away at Brainly.