At the most general level, the goal of this project is to develop a philosophical framework in which we can explain why visualisation works when it works, and why it fails when it fails. Visualisation, in this context, refers to the use of visual artefacts, like charts, that depict data, and that are used to reason about these data (visualisation as a tool for inference) or to argue in favour of a conclusion that is (supposedly) supported by the data that are depicted (visualisation as an argumentative or rhetorical device). In that sense, a visualisation is successful if it allows for reliable and efficient reasoning about the data, or if it successfully and correctly supports a given conclusion. It fails when it doesn’t. In particular, it fails when the reasoning or argumentation it supports is somehow fallacious; that is, if it misrepresents the data because it inadvertently or consciously distorts what can be concluded from these data.
The background against which this project is developed is double: on the one hand there is the role of visualisation within the new epistemic practices that are associated with the data-revolution (data science, analytics, the use of algorithms); on the other, there is the call within the visualisation-sciences (information visualisation, scientific visualisation, and visual analytics) to develop new theoretical frameworks that can inform the practice of visualisation, drive innovation, and lead to better predictions regarding the effectiveness of visualisations. In this context, this project strives to contribute to the critical reflexes and the development of epistemic standards that are needed as new epistemic practices arise, and to narrow the gap between existing theories on visualisation and insights (from logic, epistemology, and the philosophy of science) regarding the epistemic value of visualisations.
Progress within this project was made on two levels:
First, a more precise characterisation of the epistemological problem of visualisation was developed by (a) contrasting the problem of visualisation in the philosophical literature with how it is approached within the visualisation sciences; (b) disambiguating the object-level and meta-level inference problems in visualisation; and (c) analysing this meta-level problem as a design-problem.
Second, a formal analysis of data-transformations was developed in which it is possible to reason about simple and complex data-objects, as well as about the transformations (combine, aggregate, abstract, ...) we rely on to construct and modify such data-objects.