Data literate educators can generate questions about learning in their classes; collect and analyze classroom data to answer them; and develop inferences and explanations. Two elements may promote data literacy: (a) breadth of classroom-based data collection and (b) depth of analysis. We examined these in inquiries conducted by 80 preservice teachers of secondary English in diverse classrooms over a 6-year period. Analyzing products, processes, and self-reports, we found inquiries evidenced a range in breadth of data collection and depth of analysis. Qualitative themes and two cases illustrate data analysis processes and challenges of pattern finding, initially crude analyses in striving for depth, and the need for data literacy mentoring. (Contains 1 table and 3 figures.)