Final answer:
Instructors having a harder time remembering names of new students exemplifies interference in memory.
Step-by-step explanation:
The instructor's difficulty in remembering names of new students because they have learned the names of many students in the past exemplifies the concept of interference in memory. Interference occurs when old information hinders the recall of newly learned information. In this case, the previous names of students interfere with the instructor's ability to remember the new names.