Multivariate label-based thematic maps

This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal if Cartography on 23 March 2017, available online: http://www.tandfonline.com/10.1080/23729333.2017.1301346. The rich history of cartography and typography indicates that typographic attributes, such as bold, italic and size, can be used to represent data in labels on thematic maps. These typographic attributes are itemized and characterized for encoding literal, categorical and quantitative data. Label-based thematic maps are shown, including examples that scale to multiple data attributes and a large number of entities. Multiple approaches to handle long labels are considered. Positional and proportional encoding apply attributes to portions of labels for encoding a large number of data attributes or quantitative values. Quantitative evaluation indicates label-based thematic maps may outperform choropleth maps for some tasks. Qualitative evaluation provides guidance for design considerations

Visual Clutter Study for Pedestrian Using Large Scale Naturalistic Driving Data

Some of the pedestrian crashes are due to driver’s late or difficult perception of pedestrian’s appearance. Recognition of pedestrians during driving is a complex cognitive activity. Visual clutter analysis can be used to study the factors that affect human visual search efficiency and help design advanced driver assistant system for better decision making and user experience. In this thesis, we propose the pedestrian perception evaluation model which can quantitatively analyze the pedestrian perception difficulty using naturalistic driving data. An efficient detection framework was developed to locate pedestrians within large scale naturalistic driving data. Visual clutter analysis was used to study the factors that may affect the driver’s ability to perceive pedestrian appearance. The candidate factors were explored by the designed exploratory study using naturalistic driving data and a bottom-up image-based pedestrian clutter metric was proposed to quantify the pedestrian perception difficulty in naturalistic driving data. Based on the proposed bottom-up clutter metrics and top-down pedestrian appearance based estimator, a Bayesian probabilistic pedestrian perception evaluation model was further constructed to simulate the pedestrian perception process

An investigation into the emotion-cognition interaction and sub-clinical anxiety

This thesis combines behavioural and electrophysiological approaches in the study of the emotion-cognition interaction and sub-clinical anxiety. The research questions addressed in this thesis concern, specifically: the impact of emotion on attention; the interplay between attention and emotion in anxiety;and the cognitive construct of affect. Chapter 1 provides an introduction to emotion research, cognitive models of anxiety and motivates the thesis. Chapter 2 investigates whether affective processing is automatic. More specifically, to elucidate whether facilitated processing of threat in anxiety, evidenced by emotion-related ERP modulations, requires attentional resources. It was previously reported that emotional expression effects on ERP waveforms were completely eliminated when attention was directed away from emotional faces to other task-relevant locations (Eimer et al., 2003). However, Bishop et al. (2004) reported that threat-related stimuli can evoke amygdala activity without attentional engagement or conscious awareness in high-anxious but not low-anxious participants. Spatial attention was manipulated using a similar paradigm as Vuilleumier et al. (2001) and Holmes et al. (2003), to investigate the mechanism underlying the threat-related processing bias in anxiety by examining the influence of spatial attention and trait anxiety levels on established ERP modulations by emotional stimuli. Participants were instructed to match two peripheral faces or two peripheral Landolt squares. The Landolt squares task was selected since this is an attentionally demanding task and would likely consume most, if not all, attention resources. The ERP data did not offer support to the claim that affective stimuli are processed during unattended conditions in high-anxious but not low-anxious participants. Rather, it questions whether a preattentive processing bias for emotional faces is specific to heightened anxiety. This is based on the finding of an enhanced LPP response for threat/happy versus neutral faces and an enhanced slow wave for threat versus neutral faces, neither modulated by the focus of attention for both high and low anxiety groups. Chapter 3 investigated the delayed disengagement hypothesis proposed by Fox and colleagues (2001) as the mechanism underlying the threat-related attentional bias in anxiety. This was done by measuring N2pc and LRP latencies while participants performed an adapted version of the spatial cueing task.Stimuli consisted of a central affective image (either a face or IAPS picture, depending on condition) flanked to the left and right by a letter/number pair. Participants had to direct their attention to the left or right of a central affective image to make an orientation judgement of the letter stimulus. It was hypothesised that if threat-related stimuli are able to prolong attentional processing, N2pc onset should be delayed relative to the neutral condition. However, N2pc latency was not modulated by emotional valence of the central image, for either high or low anxiety groups. Thus, this finding does not provide support for the locus of the threat-related bias to the disengage component of attention. Chapter 4 further investigated the pattern of attentional deployment in the threat-related bias in anxiety. This was done by measuring task-switching ability between neutral and emotional tasks using an adapted version of Johnson’s (in press) attentional control capacity for emotional representations (ACCE) task. Participants performed either an emotional judgement or a neutral judgement task on a compound stimulus that consisted of an affective image (either happy versus fearful faces in the faces condition, or positive versus negative IAPS pictures in the IAPS condition) with a word located centrally across the image (real word versus pseudo-word). Participants scoring higher in trait anxiety were faster to switch from a neutral to a threatening mental set. This improved ability to switch attention to the emotional judgement task when threatening faces are presented is in accordance with a hypervigilance theory of anxiety. However, this processing bias for threat in anxiety was only apparent for emotional faces and not affective scenes, despite the fact that pictures depicting aversive threat scenes were used (e.g., violence, mutilation). This is discussed in more detail with respect to the social significance of salient stimuli. Chapter 5 in a pair of experiments sought to investigate how affect is mentally represented and specifically questions whether affect is represented on the basis of a conceptual metaphor linking direction and affect. The data suggest that the vertical position metaphor underlies our understanding of the relatively abstract concept of affect and is implicitly active, where positive equates with ‘upwards’ and negative with ‘downwards’. Metaphor-compatible directional movements were demonstrated to facilitate response latencies, such that participants were relatively faster to make upward responses to positively-evaluated words and downward responses to negatively-evaluated words than to metaphorincompatible stimulus-response mappings. The finding suggests that popular use of linguistic metaphors depicting spatial representation of affect may reflect our underlying cognitive construct of the abstract concept of valence. Chapter 6 summarises the research in the thesis and implications of the present results are discussed, in particular in relation to cognitive models of anxiety. Areas of possible future research are provided

A Multiple Case Study of Primary Grade School Teachers\u27 Experiences with Using Colors to Teach Writing

In this case study, I focused on understanding how primary grade school teachers in public schools in the United States use colors during writing instruction. During literacy instruction, the teacher communicates how to perform the writing process for students to become effective writers. Primary grade school teachers described how and why they use colors during writing instruction and how they learned to use colors for writing instruction and to assess their students’ writing. The theory guiding this study is Jerome Bruner’s instructional theory, supported by Cambourne’s conditions for literacy learning and the sociocultural writing theory. Data were collected through individual interviews, examining teacher-created documents developed during writing instruction, and observations of teachers using colors to provide writing instruction. To create a comprehensive description of each case, the data were first analyzed using a within-case analysis followed by a cross-case analysis. Similarities and differences between the teachers’ experiences regarding using colors during writing instruction were identified during the cross-case analysis. Twelve primary grade school teachers who work at public schools in the United States participated in this study. They provided more than 50 documents that they had created during writing instruction, even though they expressed having limited training. While participants had not received any training on how to use colors, they used colors during writing instruction in numerous ways to help students to discriminate between things, which makes writing easier for the students

HindSight: Encouraging Exploration through Direct Encoding of Personal Interaction History

Physical and digital objects often leave markers of our use. Website links turn purple after we visit them, for example, showing us information we have yet to explore. These “footprints” of interaction offer substantial benefits in information saturated environments - they enable us to easily revisit old information, systematically explore new information, and quickly resume tasks after interruption. While applying these design principles have been successful in HCI contexts, direct encodings of personal interaction history have received scarce attention in data visualization. One reason is that there is little guidance for integrating history into visualizations where many visual channels are already occupied by data. More importantly, there is not firm evidence that making users aware of their interaction history results in benefits with regards to exploration or insights. Following these observations, we propose HindSight - an umbrella term for the design space of representing interaction history directly in existing data visualizations. In this paper, we examine the value of HindSight principles by augmenting existing visualizations with visual indicators of user interaction history (e.g. How the Recession Shaped the Economy in 255 Charts, NYTimes). In controlled experiments of over 400 participants, we found that HindSight designs generally encouraged people to visit more data and recall different insights after interaction. The results of our experiments suggest that simple additions to visualizations can make users aware of their interaction history, and that these additions significantly impact users\u27 exploration and insights