Answer: Perceptual Set
Step-by-step explanation:
Perceptual set is denoted as set of expectations that predeposits in mind for perceiving towards other people , situation and things. Person tends to focus on noticing certain thing and avoiding other details about the situation or person.
According to the question, perceptual set is formed in mind of Timmy about the teachers behavior as he has predeposited thoughts about him.He will be noticing yelling and strictness traits and ignore other features of the teacher due to past experience while perceiving towards him.