Abstract
We undertook a user study to evaluate whether the perceived utility of some common open data sets for family doctors would increase if they are rendered in interactive heat maps. We also investigated whether Parallel Coordinates (PC) are perceived as a convenient diagram to summarize multiple patients data; and whether making PCs interactive would increase their informativity. We interviewed 29 expert family doctors through a questionnaire to find out that: interactive maps make health datasets be perceived as more useful, especially in regard to registers on exposure to carcinogens. PCs were found to be informative visualizations but making them interactive increases their perceived informativity. In light of this evidence, designing for better interactivity is worthy of further efforts in Human-Data Interaction research.