Digital sketch maps and eye tracking statistics as instruments to obtain insights into spatial cognition

This paper explores map users' cognitive processes in learning, acquiring and remembering information presented via screen maps. In this context, we conducted a mixed-methods user experiment employing digital sketch maps and eye tracking. On the one hand, the performance of the participants was assessed based on the order with which the objects were drawn and the influence of visual variables (e.g. presence & location, size, shape, color). On the other hand, trial durations and eye tracking statistics such as average duration of fixations, and number of fixations per seconds were compared. Moreover, selected AoIs (Area of Interests) were explored to gain a deeper insight on visual behavior of map users. Depending on the normality of the data, we used either two-way ANOVA or Mann-Whitney U test to inspect the significance of the results. Based on the evaluation of the drawing order, we observed that experts and males drew roads first whereas; novices and females focused more on hydrographic object. According to the assessment of drawn elements, no significant differences emerged between neither experts and novices, nor females and males for the retrieval of spatial information presented on 2D maps with a simple design and content. The differences in trial durations between novices and experts were not statistically significant while both studying and drawing. Similarly, no significant difference occurred between female and male participants for either studying or drawing. Eye tracking metrics also supported these findings. For average duration of fixation, there was found no significant difference between experts and novices, as well as between females and males. Similarly, no significant differences were found for the mean number of fixation

Eye-tracking Analysis of Interactive 3D Geovisualization

This paper describes a new tool for eye-tracking data and their analysis with the use of interactive 3D models. This tool helps to analyse interactive 3D models easier than by time-consuming, frame-by-frame investigation of captured screen recordings with superimposed scanpaths. The main function of this tool, called 3DgazeR, is to calculate 3D coordinates (X, Y, Z coordinates of the 3D scene) for individual points of view. These 3D coordinates can be calculated from the values of the position and orientation of a virtual camera and the 2D coordinates of the gaze upon the screen. The functionality of 3DgazeR is introduced in a case study example using Digital Elevation Models as stimuli. The purpose of the case study was to verify the functionality of the tool and discover the most suitable visualization methods for geographic 3D models. Five selected methods are presented in the results section of the paper. Most of the output was created in a Geographic Information System. 3DgazeR works with generic CSV files, SMI eye-tracker, and the low-cost EyeTribe tracker connected with open source application OGAMA. It can compute 3D coordinates from raw data and fixations

Detection of moving point symbols on cartographic backgrounds

The present paper presents the performance of an experimental cartographic study towards the examination of the minimum duration threshold required for the detection by the central vision of a moving point symbol on cartographic backgrounds. The examined threshold is investigated using backgrounds with discriminant levels of information. The experimental process is based on the collection (under free viewing conditions) and the analysis of eye movement recordings. The computation of fixation derived statistical metrics allows the calculation of the examined threshold as well as the study of the general visual reaction of map users. The critical duration threshold calculated within the present study corresponds to a time span around 400msec. The results of the analysis indicate meaningful evidences about these issues while the suggested approach can be applied towards the examination of perception thresholds related to changes occurred on dynamic stimuli

Airborne lidar experiments at the Savannah River Plant

The results of remote sensing experiments at the Department of Energy (DOE) Savannah River Nuclear Facility utilizing the NASA Airborne Oceanographic Lidar (AOL) are presented. The flights were conducted in support of the numerous environmental monitoring requirements associated with the operation of the facility and for the purpose of furthering research and development of airborne lidar technology. Areas of application include airborne laser topographic mapping, hydrologic studies using fluorescent tracer dye, timber volume estimation, baseline characterization of wetlands, and aquatic chlorophyll and photopigment measurements. Conclusions relative to the usability of airborne lidar technology for the DOE for each of these remote sensing applications are discussed

Study of the attentive behavior of novice and expert map users using eye tracking

The aim of this paper is to gain better understanding of the way map users read and interpret the visual stimuli presented to them and how this can be influenced. In particular, the difference between expert and novice map users is considered. In a user study, the participants studied four screen maps which had been manipulated to introduce deviations. The eye movements of 24 expert and novice participants were tracked, recorded, and analyzed (both visually and statistically) based on a grid of Areas of Interest. These visual analyses are essential for studying the spatial dimension of maps to identify problems in design. In this research, we used visualization of eye movement metrics (fixation count and duration) in a 2D and 3D grid and a statistical comparison of the grid cells. The results show that the users' eye movements clearly reflect the main elements on the map. The users' attentive behavior is influenced by deviating colors, as their attention is drawn to it. This could also influence the users' interpretation process. Both user groups encountered difficulties when trying to interpret and store map objects that were mirrored. Insights into how different types of map users read and interpret map content are essential in this fast-evolving era of digital cartographic products

The Influence of the Online Availability of USGS Topographic Maps on Weeding Decisions in Academic Libraries

This study looked at the degree to which the online availability of U.S. Geological Survey historical topographic maps affects academic libraries’ decisions to withdraw the print versions of those maps. Other factors in making the decisions, such as usage, user preferences, support of academic programs, user discovery, shelving location, and printing options, were also investigated. Results show that while in 40% of the cases the online USGS historical topographic maps influenced the decision to weed, the need for space was the overwhelming driver of print USGS topographic map collection weeding within the past ten years