Researchers currently rely on ad hoc datasets to train automated visualization tools and evaluate the effectiveness of visualization designs. These exemplars often lack the characteristics of real-world datasets, and their one-off nature makes it difficult to compare different techniques. In this paper, we present VizNet: a large-scale corpus of over 31 million datasets compiled from open data repositories and online visualization galleries. On average, these datasets comprise 17 records over 3 dimensions and across the corpus, we find 51% of the dimensions record categorical data, 44% quantitative, and only 5% temporal. VizNet provides the necessary common baseline for comparing visualization design techniques, and developing benchmark models and algorithms for automating visual analysis. To demonstrate VizNet's utility as a platform for conducting online crowdsourced experiments at scale, we replicate a prior study assessing the influence of user task and data distribution on visual encoding effectiveness, and extend it by considering an additional task: outlier detection. To contend with running such studies at scale, we demonstrate how a metric of perceptual effectiveness can be learned from experimental results, and show its predictive power across test datasets.
@article{arxiv.1905.04616,
title = {VizNet: Towards A Large-Scale Visualization Learning and Benchmarking Repository},
author = {Kevin Hu and Neil Gaikwad and Michiel Bakker and Madelon Hulsebos and Emanuel Zgraggen and César Hidalgo and Tim Kraska and Guoliang Li and Arvind Satyanarayan and Çağatay Demiralp},
journal= {arXiv preprint arXiv:1905.04616},
year = {2019}
}