Data visualizations in journalistic media studied from the perspectives of visual-numeric literacy, everyday mathematics and mathematization as a social process

Abstract

Data visualizations (DVs) are visual representations of quantitative data, which are used to convey information. The aim of my PhD research was to better understand the implications for readers of the use of DVs in journalistic media. Journalistic DVs were explored from the perspectives of (1) Visual-numeric literacy (VNL), which describes the capabilities that DVs demand from readers, (2) Everyday mathematics, which is the mathematics that people engage with in various life situations (school, work, domestic life, etc.), and (3) Mathematization as a social process, the tendency of some human practices to become increasingly quantitative and mathematical. In this PhD, the main theoretical perspective was social semiotics, but it was also informed by a sociological perspective of late modernity. The empirical base for the studies in this PhD was textual analysis of newspaper weather forecasts (NWFs) in the period 1945-2020 and journalistic COVID-19 DVs, and an analysis of interviews with young adults on their sense making of COVID-19 DVs. The analysis revealed that NWFs shifted over time from verbally ‘telling’ readers about the weather, to offering abundant information in tables and maps that the readers must organize and interpret themselves. The senders’ voice changed from being a conversationalist or scientist to a blend of an advertiser and a scientist. These changes relate to processes of mathematization in meteorology and journalism. The analysis of journalistic COVID-19 DVs showed that the DVs convey much information (how many, where, how it changes, etc.) through numerous formats (maps, line graphs, etc.), complex sign systems (coordinates, relative numbers, color codes, etc.) and flexible use of conventions (e.g., missing vertical axis). Readers were expected to make sense of these DVs and interpret their significance and implications. Cues about data sources, data handling methods and errors invited readers to reflect on the trustworthiness of the data and their visualization. The interviews showed that adults have unequal opportunities for making sense of DVs. It was observed that the three aspects of VNL, decoding, acting (e.g. toggling in a DV, using a DV for making decisions) and reflection were mutually supporting one another, and a readers’ background knowledgeabout the situation (i.e., COVID-19) supported the understanding of the sign system. Regarding VNL, everyday mathematics, mathematization as a social process and the connection between these perspectives my research offers evidence that the use of DVs in journalistic media has increased over time, that they mediate information from experts (meteorologists, epidemiologists) to lay people, that the VNL required of readers is quite sophisticated, and that journalistic DVs have changed everyday mathematics. The changes do not consist of more or less mathematics, but of an increased variety of quantitative information presented in visual, flexible and informal systems. A sociological synthesis relates the complexities of reading DVs to mathematization as a social process. For example, globalization and reembedding (of journalism, DVs, meteorology, epidemiology, data collections, mathematical models, VNL, etc.) enable readers of DVs to access more and more diverse information yet creates obstacles for intimacy and trust through the increased opacity of underlying data collections and mathematical models. Insight into these mathematical processes is necessary for reflecting critically on DVs. Mathematics education can play a key role in helping students to develop their VNL and pave the way for participating in society, and lifelong learning.