In the visualization community, it is often assumed that visual data storytelling increases memorability and engagement, making it more effective at communicating information. However, many assumptions about the efficacy of storytelling in visualization lack empirical evaluation. Contributing to an emerging body of work, we study whether selected techniques commonly used in visual data storytelling influence people's attitudes towards immigration. We compare (a) personal visual narratives designed to generate empathy; (b) structured visual narratives of aggregates of people; and (c) an exploratory visualization without narrative acting as a control condition. We conducted two crowdsourced between‐subject studies comparing the three conditions, each with 300 participants. To assess the differences in attitudes between conditions, we adopted established scales from the social sciences used in the European Social Survey (ESS). Although we found some differences between conditions, the effects on people's attitudes are smaller than we expected. Our findings suggest that we need to be more careful when it comes to our expectations about the effects visual data storytelling can have on attitudes. Additional material: https://flowstory.github.io/attitudes/.

No abstract

This article introduces interactive video maps for the web. The main component of video maps is a video stream that is areally georeferenced to a spatial reference system in the same way rectified raster orthoimages are georeferenced. The areal georeference allows for interactivity that goes beyond the play, pause, and stop functionality of video player software. We highlight two types of functionality, allowing the user to (1) combine the video stream layer with other raster and vector map layers and (2) adjust the projection of the map in real time. We exemplify video maps by A Year in the Life of Earth's CO 2 , an interactive video map that visualizes the results of a high-resolution NASA computer model of global atmospheric carbon dioxide distribution. The map shows how carbon dioxide travels around the globe over the course of one year. We use a combination of WebGL, a programming interface to the hardware-accelerated graphics pipeline, and HTML5 video for adding an areally georeferenced video layer to other map layers, and for the on the fly projection of the video stream in the web browser.ARTICLE HISTORY

No abstract