This research compared undergraduate Novices and PhD Experts in psychology and business in their exploration of psychology and business domain graphs. An overall expertise effect in graph explanation was found. Results indicated that Novices paused longer than Experts before beginning their explanations. Qualitative analyses showed that Experts were generally more complete in their explanations, generating more inferences, more quantitative statements, and more conceptual messages. Psychology Experts tended to generate more complete explanations for psychology-domain graphs whereas Business Experts generate less complete explanations for business-domain graphs. The results suggest that Experts have superior strategies to Novices in graph exploration that may be accommodated by the graph comprehension model of Pinker (1990). An implication of these results is that simple instructions may greatly enhance the data literacy of students and might be embodied in data visualization tools for adults and researchers as well. [For complete proceedings, see ED557311.]