The Categorizer is an interactive gallery that allows students to organize their peers' collection of work under their own thematic schemes. Students can observe the function rules that generated different fractions, create their own categorical schemes for sorting and comparing fractals, and can see an aggregation of their peers' categorization schemes. It serves as a site to investigate the potential that exploring an entire body of student-generated work as an object of analysis and reflection can hold for student motivation, analogical reasoning, and learning.