Procedure

1. Provide students with several pictures or words that are related to students' topic of study (e.g., Superman, Spider-Man, and Thor).

2. Include one picture or word that seems to fit into the same category (e.g., Batman, an antihero) to heighten the challenge, or include one picture or word that is clearly a misfit (e.g., Gotham City).

3. Ask each student, working individually, to select a picture or word from the group that they believe to be an outlier with a key difference.

4. Sort students into small groups. Group members may have the same answers or a variety of different answers. Ask each student to explain the reasoning behind their choice to their group.

5. Time permitting, ask volunteers to share their choice and reasoning.

6. Optionally, to extend this activity, ask volunteers to try persuading their classmates of their reasoning. Students who change their answers based on their classmates' reasoning can join their classmates' groups.