In a research project investigating power relationships in speech, first-semester college freshmen and college seniors were invited to a laboratory in equal numbers. there, they were asked to chat and get to know each other before the real experiment began. the researchers actually analyzed the number of interruptions that people made in the course of a conversation. this is an example of research.

laboratory observation

Explanation:

Laboratory observation occurs when researchers gather a group of people to be participants in their tests, so that investigators execute their experiments as similarly as possible to real life but in a controlled environment. Therefore, researchers can regulate the setting and reduce outside influences.

i can't see the full page, therefore, can't answer it

explanation:

substitution is the answer in this case