Avoidant personality disorder is characterized by a desire for social relationships, but a fear of being rejected or feeling inadequate for others. This is different from Schizoid, because Schizoid individuals do not desire relationships with others, and want to remain alone. The trickiest differentiation might be between Avoidant and Schizotypal, but Schizotypal individuals tend to remain isolated because of odd thinking, or "magical beliefs".
Actual medical school lecture was good for something -
Avoidant: Charlie Brown
Schizotypal: Luna Lovegood from Harry Potter
Psych personality disorders easier when remembering a movie/TV show.