1. I believe the answer is: Control
The word 'control' in psychology indicates the act to influence other people to do our bidding. Even though the influence could be implemented through psychological tricks to a certain extend, control is more often considered as unethical and not considered to be a goal of psychology.
2. I believe the answer is: Measure
The measurement in this context refers to the type of data that psychologists used for their basis of consideration along with how they obtain it. Using different measurements in research could dramatically alter the end result/conclusion of the research.
3. I believe the answer is: Casual observation
Casual observation refers to the type of observation that is focused on figuring out a certain type of cause and effect relationships between research variables. When observing animals, we will see various type of behaviours that is uncommon among humans, and the researchers would use casual observation to find out the cause of why those animals behaving in that certain way.