Impact of Design Decisions in Scanpath Modeling
Parvin Emami, Yue Jiang, Zixin Guo, Luis A. Leiva
TL;DR
This work addresses the sensitivity of GUI scanpath predictions to non-learned design parameters in saliency models. By systematically varying input image size, IOR decay, and masking radius in DeepGaze++ on the UEyes dataset, the authors quantify impacts across DTW, Eyenalysis, Determinism, and Laminarity, and demonstrate the generalizability of findings to other models and datasets like MASSVIS. They introduce a generalized IOR decay, $\gamma^{(n - i - 1)}$, and identify robust parameter settings (e.g., square inputs, $\gamma = 0.1$, masking radius around $0.05$) that improve several metrics. The results offer practical guidance for building and evaluating scanpath models and underscore the importance of reporting design choices in GUI saliency research, with publicly available code and models to promote replicability.
Abstract
Modeling visual saliency in graphical user interfaces (GUIs) allows to understand how people perceive GUI designs and what elements attract their attention. One aspect that is often overlooked is the fact that computational models depend on a series of design parameters that are not straightforward to decide. We systematically analyze how different design parameters affect scanpath evaluation metrics using a state-of-the-art computational model (DeepGaze++). We particularly focus on three design parameters: input image size, inhibition-of-return decay, and masking radius. We show that even small variations of these design parameters have a noticeable impact on standard evaluation metrics such as DTW or Eyenalysis. These effects also occur in other scanpath models, such as UMSS and ScanGAN, and in other datasets such as MASSVIS. Taken together, our results put forward the impact of design decisions for predicting users' viewing behavior on GUIs.
