Abstract. (Gen)AI diversity is not merely an ethical issue. From
the perspective of geographic information science (GIScience), it could
be interpreted as a function of uncertainty and as a form of cognitive
bias, embedded in AI outputs. Recent work has sought to develop
information-theoretic diversity measures and apply them to evaluate
AI-chatbot outputs in a geographic context. As the AI ecosystem to which
we are exposed on a daily basis becomes rapidly multimodal, we believe
it is important to examine geographic diversity across various
modalities. Focusing on images, this paper aims to fill this research
gap. First, we select the GPT and DALL·E models as state-of-the-art
examples and point out how assessing their geographic diversity involves
various stages, including prompt revision and image generation. Then,
taking inspiration from species diversity measures in ecological
research, we incorporate similarity weighting into the measurement of
geographic diversity. Next, we demonstrate how to evaluate geographic
diversity in image generation through a case study. Our analysis reveals
several counterintuitive findings. For instance, older models can
exhibit greater geographic diversity despite producing lower-quality
images, and prompt revision yields greater geographic diversity than
image generation. At the same time, we observe explicit model
homogeneity underlying the lack of geographic diversity, as the selected
models consistently depict the same prototypical geo-specific feature or
similar features. This is concerning, as it risks producing
stereotypical representations of places. Reproducibility review
available at: https://doi.org/10.17605/OSF.IO/vcgy2