Čeněk Šašinka

Thematic uncertainty visualization usability – comparison of basic methods

The uncertainty of geographic data and visualization can be viewed from different angles. While the conceptual and theoretical base is quite wide, visualization tools and pilot projects are rare, and there exist only a few studies dealing with the users ability to cope with uncertainty visualization efficiency. This article introduces two widely used uncertainty visualization methods – maps compared and maps combined – and focuses on the usability issues of these methods. A combination of the regular kriging interpolation method and interpolation uncertainty values was used for maps compared, while the whitening approach was applied for maps combined. During this study, we electronically interviewed and tested more than 100 participants with backgrounds in geography or computer science. Both the above-mentioned methods were tested on three different levels. On the first level, the intuitiveness of the whitening method was questioned. On the second level, both methods were compared taking into account the simple decoding of predicted values (interpolation results), uncertainty decoding and the decoding of both variables (uncertainty and interpolation results) at the same time. Finally, the ability to compare two or more values was tested for the same combinations. Both correctness and processing time were recorded in order to enable further statistical processing. The overall testing was performed within the web-interactive environment developed specifically for interdisciplinary (cartographic–psychology) purposes.

Cartographic Design and Usability of Visual Variables for Linear Features

This article addresses the measurement and assessment of response times and error rates in map-reading tasks relative to various modes of linear feature visualization. In a between-subject design study, participants completed a set of map-reading tasks generated by approaches to a traffic problem. These entailed quick and correct decoding of graphically represented quantitative and qualitative spatial information. The tasks first involved the decoding of one graphic variable, then of two variables simultaneously. While alternative representations of qualitative information included colour hue and symbol shape, the quantitative information was communicated either through symbol size or colour value. In bivariate tasks, quantitative and qualitative graphical elements were combined in a single display. Individual differences were also examined. The concept of cognitive style partially explains the variability in people’s perception and thinking, describing individual preferences in object representation and problem-solving strategies. The data obtained in the experiment suggest that alternative forms of visualization may have different impacts on performance in map-reading tasks: colour hue and size proved more efficient in communicating information than shape and colour value. Apart from this, it was shown that individual facets of cognitive style may affect task performance, depending on the type of visualization employed.

EyeTribe Tracker Data Accuracy Evaluation and Its Interconnection with Hypothesis Software for Cartographic Purposes

The mixed research design is a progressive methodological discourse that combines the advantages of quantitative and qualitative methods. Its possibilities of application are, however, dependent on the efficiency with which the particular research techniques are used and combined. The aim of the paper is to introduce the possible combination of Hypothesis with EyeTribe tracker. The Hypothesis is intended for quantitative data acquisition and the EyeTribe is intended for qualitative (eye-tracking) data recording. In the first part of the paper, Hypothesis software is described. The Hypothesis platform provides an environment for web-based computerized experiment design and mass data collection. Then, evaluation of the accuracy of data recorded by EyeTribe tracker was performed with the use of concurrent recording together with the SMI RED 250 eye-tracker. Both qualitative and quantitative results showed that data accuracy is sufficient for cartographic research. In the third part of the paper, a system for connecting EyeTribe tracker and Hypothesis software is presented. The interconnection was performed with the help of developed web application HypOgama. The created system uses open-source software OGAMA for recording the eye-movements of participants together with quantitative data from Hypothesis. The final part of the paper describes the integrated research system combining Hypothesis and EyeTribe.

Selected Issues of Experimental Testing in Cartography

Kniha sestava ze dvou hlavnich casti. V prvni casti jsou představeny teoreticke koncepty ve vztahu k individualnim rozdilům uživatelů a výzkumu uživatelske přivětivosti. Druha caast je zaměřena na představeni software Hypothesis

Human-Computer Interaction in Real-3D and Pseudo-3D Cartographic Visualization: A Comparative Study

This chapter summarizes the results of an experiment performed as basic research on the three-dimensional (3D) display of geographical information using two alternative control devices (a Wii remote controller and a mouse). The aim was to explore the influence of a specific type of visualization on the human understanding of depicted geographical information and to discover which type of display—real 3D or pseudo-3D combined with a Wii remote controller and a computer mouse—can be considered better for working with geographical bases. The research was set up as an exploratory analysis and examined the performance of 17 participants. As expected, there were differences in the results between the types of visualization and devices used. Real-3D visualization appeared faster but less suitable for the successful management of tasks than the pseudo-3D visualization. We found no significant differences based on the controlling device when elaborating tasks, but we believe the Wii remote controller device to be a promising device for future studies.

When the Display Matters: A Multifaceted Perspective on 3D Geovisualizations

Abstract This study explores the influence of stereoscopic (real) 3D and monoscopic (pseudo) 3D visualization on the human ability to reckon altitude information in noninteractive and interactive 3D geovisualizations. A two phased experiment was carried out to compare the performance of two groups of participants, one of them using the real 3D and the other one pseudo 3D visualization of geographical data. A homogeneous group of 61 psychology students, inexperienced in processing of geographical data, were tested with respect to their efficiency at identifying altitudes of the displayed landscape. The first phase of the experiment was designed as non-interactive, where static 3D visual displayswere presented; the second phase was designed as interactive and the participants were allowed to explore the scene by adjusting the position of the virtual camera. The investigated variables included accuracy at altitude identification, time demands and the amount of the participant’s motor activity performed during interaction with geovisualization. The interface was created using a Motion Capture system, Wii Remote Controller, widescreen projection and the passive Dolby 3D technology (for real 3D vision). The real 3D visual display was shown to significantly increase the accuracy of the landscape altitude identification in non-interactive tasks. As expected, in the interactive phase there were differences in accuracy flattened out between groups due to the possibility of interaction, with no other statistically significant differences in completion times or motor activity. The increased number of omitted objects in real 3D condition was further subjected to an exploratory analysis.

Identification of altitude profiles in 3D geovisualizations: the role of interaction and spatial abilities

ABSTRACT Three-dimensional geovisualizations are currently pushed both by technological development and by the demands of experts in various applied areas. In the presented empirical study, we compared the features of real 3D (stereoscopic) versus pseudo 3D (monoscopic) geovisualizations in static and interactive digital elevation models. We tested 39 high-school students in their ability to identify the correct terrain profile from digital elevation models. Students’ performance was recorded and further analysed with respect to their spatial abilities, which were measured by a psychological mental rotation test and think aloud protocol. The results of the study indicated that the influence of the type of 3D visualization (monoscopic/stereoscopic) on the performance of the users is not clear, the level of navigational interactivity has significant influence on the usability of a particular 3D visualization, and finally no influences of the spatial abilities on the performance of the user within the 3D environment were identified.

Perceptions of Various Cartographic Representations Under Specific Conditions

Maps are usually better abstractions of reality than other media and allow easier perception of included spatial information. This fact makes maps convenient for several specialised societal purposes, including emergency management and transportation, among others.

The Hypothesis Platform : An Online Tool for Experimental Research into Work with Maps and Behavior in Electronic Environments

The article presents a testing platform named Hypothesis. The software was developed primarily for the purposes of experimental research in cartography and psychological diagnostics. Hypothesis is an event-logger application which can be used for the recording of events and their real-time processing, if needed. The platform allows for the application of Computerized Adaptive Testing. The modularity of the platform makes it possible to integrate various Processing.js-based applications for creation and presentation of rich graphic material, interactive animations, and tasks involving manipulation with 3D objects. The Manager Module allows not only the administration of user accounts and tests but also serves as a data export tool. Raw data is exported from the central database in text format and then converted in the selection module into a format suitable for statistical analysis. The platform has many functions e.g., the creation and administration of tasks with real-time interaction between several participants (“multi-player function”) and those where a single user completes several tests simultaneously (“multi-task function”). The platform may be useful e.g., for research in experimental economics or for studies involving collaborative tasks. In addition, connection of the platform to an eye-tracking system is also possible.

Cross-cultural differences in figure–ground perception of cartographic stimuli

ABSTRACT This article reports on an empirical study investigating cultural differences in the visuospatial perception and cognition of qualitative point symbols shown on reference maps. We developed two informationally equivalent symbol sets depicted on identical reference maps that were shown to Czech and Chinese map readers. The symbols varied in visual contrast with respect to the base map. Our empirical results suggest the existence of cultural influences on map reading, but not in the predicted direction based on the previous cross-cultural studies. Our findings stress the importance of considering the cultural background of map readers, especially when designing reference maps aimed for global online use.