Twenty years ago, Arthur Stern’s article “When Is a Paragraph?” posed a revealing challenge to graduate-level Education students: identify the number of paragraphs into which a piece should be divided and show where the paragraph divisions should occur. Stern’s students divided the 500-word essay into two, three, four, and five paragraphs, and provided credible justifications for their various paragraph arrangements, not all the same but logical, based on ideational shifts. At the same time, when Stern’s English-teacher students self-reported their definitions of a paragraph, they presented a traditional view—a paragraph is a unit of discourse made of several sentences that develop a central idea around an identifiable topic sentence. In essence, their English-teacher conception of a paragraph was as a composition in miniature, based on structural design, rather than the ideational shifts that guided them in the exercise. Stern had uncovered a discrepancy between the operational understanding of the paragraph and student/teacher beliefs about it.