Elicit non-trivial dialogue from students. Guide students to reflection and analysis of the experience. Encourage students to share their perceptions and beliefs. Summarize and review similarities and differences.

Students post lists and analyze criteria.

Objective: To analyze the world of geometry based on their own experience.

Activity: Students post lists based on their collective brainstorming. The class as a whole decides if all items meet the set criteria. Their lists will be all liquids or gases; they will discover that all solids have a basic geometric shape or combination of shapes.

Assessment: Quality of group lists and student understanding of concept.