Summary: Explanations are considered to be key aids to understanding the study of mathematics, science, and other complex disciplines. This paper discusses the role of students’ explanations in making sense of data and learning to reason informally about statistical inference. We closely follow students’ explanations in which they utilize their experiences and knowledge of the context, statistical tools, and ideas to support their emerging informal inferential reasoning (IIR). This case study focuses on two independent inquiry episodes of sixth-grade students (age 12) within an unstructured, inquiry-based, technology-rich learning environment that was designed to promote students’ IIR. We discuss research and practical issues related to the role of explanations and context in developing students’ IIR. (Contains 3 tables, 3 figures and 5 footnotes.) (ERIC)