The visual analysis of data presented in time-series graphs are common in single-case design (SCD) research and applied practice in school psychology. A growing body of research suggests that visual analysts' ratings are often influenced by construct-irrelevant features including Y-axis truncation and compression of the number of data points per X- to Y-axis ratio. We developed and tested two brief interventions, based on the research in cognitive and visual science, to reduce visual analysts' inconsistency when viewing unstandardized graphs. Two hundred practicing school psychologists visually analyzed data presented on standardized graphs and the same data again on unstandardized graphs. Across all conditions, participants were more willing to identify meaningful effects on unstandardized graphs and rated the data as showing significantly larger effects than on the corresponding standardized graphs. However, participants who answered additional (task-relevant) questions about the level or trend of graphed data showed greater rating consistency across the types of graphs in comparison to participants who answered task-irrelevant but challenging questions or control participants. Our results replicated prior research demonstrating the impact of SCD graph construction on practicing school psychologists' interpretations and provide initial support for an intervention to minimize the impact of construct-irrelevant factors. Limitations and future directions for research are discussed. [This is the online first version of an article published in "School Psychology" (ISSN 2578-4218).]