Real-time and archival data visualisation techniques in city dashboards

City dashboards have become a common smart city technology, emerging as a key means of sharing and visualising urban data for the benefit of the public and city administrations. Operating as the front-end of many cities’ data stores, dashboards display and benchmark indicators relating to city operations, characteristics, and trends, displayed through interactive visual representations of spatial and temporal patterns. Many dashboards collect, archive, and present data collected in real-time, as well as more traditional time-sliced administrative data. In this paper, we evaluate the techniques that dashboards employ to present real-time data to dashboard users. Our analysis identifies two factors that shape and differentiate real-time visual analytic tools: the dynamic nature of the data, how they are refreshed, and how the realtimeness of the data is communicated to the user; and how the tool enables archival comparison. We assess dashboard design according to the strategies used to address specific challenges associated with each factor, specifically change blindness and temporal pattern detection. We conclude by proposing effective techniques for city dashboard design

Choriented Maps: Visualizing SDG Data on Mobile Devices

Choropleth maps and graduated symbol maps are often used to visualize quantitative geographic data. However, as the number of classes grows, distinguishing between adjacent classes increasingly becomes challenging. To mitigate this issue, this work introduces two new visualization types: choriented maps (maps that use colour and orientation as variables to encode geographic information) and choriented mobile (an optimization of choriented maps for mobile devices). The maps were evaluated in a graphical perception study featuring the comparison of SDG (Sustainable Development Goal) data for several European countries. Choriented maps and choriented mobile visualizations resulted in comparable, sometimes better effectiveness and confidence scores than choropleth and graduated symbol maps. Choriented maps and choriented mobile visualizations also performed well regarding efficiency overall and performed worse only than graduated symbol maps. These results suggest that the use of colour and orientation as visual variables in combination can improve the selectivity of map symbols and user performance during the exploration of geographic data in some scenarios.Comment: Accepted for publication in the Cartographic Journa

Analisis orientado a objetos de imágenes de teledetección para cartografia forestal : bases conceptuales y un metodo de segmentacion para obtener una particion inicial para la clasificacion = Object-oriented analysis of remote sensing images for land cover mapping : Conceptual foundations and a segmentation method to derive a baseline partition for classification

El enfoque comúnmente usado para analizar las imágenes de satélite con fines cartográficos da lugar a resultados insatisfactorios debido principalmente a que únicamente utiliza los patrones espectrales de los píxeles, ignorando casi por completo la estructura espacial de la imagen. Además, la equiparación de las clases de cubierta a tipos de materiales homogéneos permite que cualquier parte arbitrariamente delimitada dentro de una tesela del mapa siga siendo un referente del concepto definido por su etiqueta. Esta posibilidad es incongruente con el modelo jerárquico del paisaje cada vez más aceptado en Ecología del Paisaje, que asume que la homogeneidad depende de la escala de observación y en cualquier caso es más semántica que biofísica, y que por tanto los paisajes son intrínsecamente heterogéneos y están compuestos de unidades (patches) que funcionan simultáneamente como un todo diferente de lo que les rodea y como partes de un todo mayor. Por tanto se hace necesario un nuevo enfoque (orientado a objetos) que sea compatible con este modelo y en el que las unidades básicas del análisis sean delimitadas de acuerdo a la variación espacial del fenómeno estudiado. Esta tesis pretende contribuir a este cambio de paradigma en teledetección, y sus objetivos concretos son: 1.- Poner de relieve las deficiencias del enfoque tradicionalmente empleado en la clasificación de imágenes de satélite. 2.- Sentar las bases conceptuales de un enfoque alternativo basado en zonas básicas clasificables como objetos. 3.- Desarrollar e implementar una versión demostrativa de un método automático que convierte una imagen multiespectral en una capa vectorial formada por esas zonas. La estrategia que se propone es producir, basándose en la estructura espacial de las imágenes, una partición de estas en la que cada región puede considerarse relativamente homogénea y diferente de sus vecinas y que además supera (aunque no por mucho) el tamaño de la unidad mínima cartografiable. Cada región se asume corresponde a un rodal que tras la clasificación será agregado junto a otros rodales vecinos en una región mayor que en conjunto pueda verse como una instancia de un cierto tipo de objetos que más tarde son representados en el mapa mediante teselas de una clase particular

Making Sense of Document Collections with Map-Based Visualizations

As map-based visualizations of documents become more ubiquitous, there is a greater need for them to support intellectual and creative high-level cognitive activities with collections of non-cartographic materials -- documents. This dissertation concerns the conceptualization of map-based visualizations as tools for sensemaking and collection understanding. As such, map-based visualizations would help people use georeferenced documents to develop understanding, gain insight, discover knowledge, and construct meaning. This dissertation explores the role of graphical representations (such as maps, Kohonen maps, pie charts, and other) and interactions with them for developing map-based visualizations capable of facilitating sensemaking activities such as collection understanding. While graphical representations make document collections more perceptually and cognitively accessible, interactions allow users to adapt representations to users’ contextual needs. By interacting with representations of documents or collections and being able to construct representations of their own, people are better able to make sense of information, comprehend complex structures, and integrate new information into their existing mental models. In sum, representations and interactions may reduce cognitive load and consequently expedite the overall time necessary for completion of sensemaking activities, which typically take much time to accomplish. The dissertation proceeds in three phases. The first phase develops a conceptual framework for translating ontological properties of collections to representations and for supporting visual tasks by means of graphical representations. The second phase concerns the cognitive benefits of interaction. It conceptualizes how interactions can help people during complex sensemaking activities. Although the interactions are explained on the example of a prototype built with Google Maps, they are independent iv of Google Maps and can be applicable to various other technologies. The third phase evaluates the utility, analytical capabilities and usability of the additional representations when users interact with a visualization prototype – VIsual COLlection EXplorer. The findings suggest that additional representations can enhance understanding of map-based visualizations of library collections: specifically, they can allow users to see trends, gaps, and patterns in ontological properties of collections

Schematisation in Hard-copy Tactile Orientation Maps

This dissertation investigates schematisation of computer-generated tactile orientation maps that support mediation of spatial knowledge of unknown urban environments. Computergenerated tactile orientation maps are designed to provide the blind with an overall impression of their surroundings. Their details are displayed by means of elevated features that are created by embossers and can be distinguished by touch. The initial observation of this dissertation states that only very little information is actually transported through tactile maps owing to the coarse resolution of tactual senses and the cognitive effort involved in the serial exploration of tactile maps. However, the differences between computer-generated, embossed tactile maps and manufactured, deep-drawn tactile maps are significant. Therefore the possibilities and confines of communicating information through tactile maps produced with embossers is a primary area of research. This dissertation has been able to demonstrate that the quality of embossed prints is an almost equal alternative to traditionally manufactured deep-drawn maps. Their great advantage is fast and individual production and (apart from the initial procurement costs for the printer)low price, accessibility and easy understanding without the need of prior time-consuming training. Simplification of tactile maps is essential, even more so than in other maps. It can be achieved by selecting a limited number from all map elements available. Qualitative simplification through schematisation may present an additional option to simplification through quantitative selection. In this context schematisation is understood as cognitively motivated simplification of geometry and synchronised maintenance of topology. Rather than further reducing the number of displayed objects, the investigation concentrates on how the presentation of different forms of streets (natural vs. straightened) and junctions (natural vs. prototypical) affects the transfer of knowledge. In a second area of research, a thesis establishes that qualitative simplification of tactile orientation maps through schematisation can enhance their usability and make them easier to understand than maps that have not been schematised. The dissertation shows that simplifying street forms and limiting them to prototypical junctions does not only accelerate map exploration but also has a beneficial influence on retention performance. The majority of participants that took part in the investigation selected a combination of both as their preferred display option. Tactile maps that have to be tediously explored through touch, uncovering every detail, complicate attaining a first impression or an overall perception. A third area of research is examined, establishing which means could facilitate map readersâ options to discover certain objects on the map quickly and without possessing a complete overview. Three types of aids are examined: guiding lines leading from the frame of the map to the object, position indicators represented by position markers at the frame of the map and coordinate specifications found within a grid on the map. The dissertation shows that all three varieties can be realised by embossers. Although a guiding line proves to be fast in size A4 tactile maps containing only one target object and few distracting objects, it also impedes further exploration of the map (similar to the grid). In the following, advantages and drawbacks of the various aids in this and other applications are discussed. In conclusion the dissertation elaborates on the linking points of all three examinations. They connect and it is argued that cognitively motivated simplification should be a principle of construction for embossed tactile orientation maps in order to support their use and comprehension. A summary establishes the recommendations that result from this dissertation regarding construction of tactile orientation maps considering the limitations through embosser constraints. Then I deliberate how to adapt schematisation of other maps contingent to intended function, previous knowledge of the map reader, and the relation between the time in which knowledge is acquired and the time it is employed. Closing the dissertation, I provide an insight into its confines and deductions and finish with a prospective view to possible transfers of the findings to other applications, e.g. multimedia or interactive maps on pin-matrix displays and devices

Cartographic Redundancy in Reducing Change Blindness in Detecting Extreme Values in Spatio-Temporal Maps

The article investigates the possibility of using cartographic redundancy to reduce the change blindness effect on spatio-temporal maps. Unlike in the case of previous research, the authors take a look at various methods of cartographic presentation and modify the visual variables in order to see how those modifications affect the user’s perception of changes on spatio-temporal maps. The study described in the following article was the first attempt at minimizing the change blindness phenomenon by manipulating graphical parameters of cartographic visualization and using various quantitative mapping methods. Research shows that cartographic redundancy is not enough to completely resolve the problem of change blindness; however, it might help reduce it

Visualising Geographically-Embedded Origin-Destination Flows: in 2D and immersive environments

This thesis develops and evaluates effective techniques for visualisation of flows (e.g. of people, trade, knowledge) between places on geographic maps. This geographically-embedded flow data contains information about geographic locations, and flows from origin locations to destination locations. We explored the design space of OD flow visualisation in both 2D and immersive environments. We do so by creating novel OD flow visualisations in both environments, and then conducting controlled user studies to evaluate different designs.Comment: PhD Thesis, Monash University, Australia, December 2018. Update: corrected typos in arXiv comment

Cartographic user interface design models for mobile Location-Based Services applications

Mobile Location-Based Services (mLBS) offer a unique combination of digital content, portability, interactivity, location-awareness and real-time information delivery, providing increased convenience and support for everyday geospatial decision-making tasks, compared to more traditional printed maps and digital cartographic products. In spite of their benefits, however, limitations inherent within mLBS technology (e.g. small screens), along with the dynamic and changeable contexts in which they are used, impact on their effectiveness for communicating geospatial information to end users and, in turn, their overall acceptance. Identifying usefulness (i.e. utility and usability) as a key factor influencing the acceptance of mLBS products, this thesis details the investigation of techniques and a methodology for designing mLBS applications that communicate geospatial information in a useful manner to non-expert, general public users. The research presented here focuses on the usefulness of the entire cartographic user interface (UI) for mLBS applications – i.e. those components that are specifically concerned with the access and representation of, and interaction with, geospatial information – differentiating it from related mLBS research and application design. Particular emphasis was placed on the usefulness of the interplay between various geospatial components of the cartographic UI, in support of a broad range of everyday geospatial tasks for non-expert users. Contributing to this, a wide array of alternative techniques for representing, presenting and interacting with geospatial information were explored. To achieve its aims, the study adopted a qualitative User-Centred Design (UCD) methodology, involving an early focus on users and their tasks, empirical measurement of usage, and iterative design and evaluation, which together ensured that all design efforts were firmly grounded in the needs and characteristics of the end users. Necessarily focused on a specific application area (tourism) and an associated user group (travellers), the UCD process employed by the research was more comprehensive than had previously been undertaken within the cartographic discipline. The primary results of the research comprise a set of cartographic UI design models for communicating geospatial information in a useful manner to the non-expert users of a tourism-related mLBS application. These incorporate a range of alternative cartographic representation, presentation and interaction techniques considered useful by representative users, with egocentric maps arguably holding the greatest importance. The wider benefits of the design models are expected to be twofold: firstly, they offer a structural foundation to researchers and developers seeking to produce useful cartographic UIs for tourism-related mLBS applications; and secondly, they provide guidance regarding specific cartographic representation, presentation and interaction techniques that offer utility and usability in particular contexts. In addition, a number of secondary research outputs offer other benefits to the scientific and commercial mLBS communities. These include the UCD research methodology – which presents a proven guide for ensuring usefulness during the design of mLBS applications in general – and a set of general recommendations for designing useful mLBS applications – which offer assistance for specific design activities while contributing empirical results to the future development of mLBS application design guidelines