Subjective information visualizations

Information Visualizations (InfoViz) are systems that require high levels of cognitive processing. They revolve around the notion of decoding and interpreting visual patterns in order to achieve certain goals. We argue that purely designing for the visual will not allow for optimum experiences since there is more to InfoViz than just the visual. Interaction is a key to achieving higher levels of knowledge. In this position paper we present a different perspective on the underlying meaning of interaction, where we describe it as incorporating both the visual and the physical activities. By physical activities we mean the physical actions upon the physical input device/s. We argue that interaction is the key element for supporting users’ subjective experiences hence these experiences should first be understood. All the discussions in this paper are based upon on going work in the field of visualizing the literature knowledge domain (LKDViz)

Haptic Experience and the Design of Drawing Interfaces

Haptic feedback has the potential to enhance users’ sense of being engaged and creative in their artwork. Current work on providing haptic feedback in computer-based drawing applications has focused mainly on the realism of the haptic sensation rather than the users’ experience of that sensation in the context of their creative work. We present a study that focuses on user experience of three haptic drawing interfaces. These interfaces were based on two different haptic metaphors, one of which mimicked familiar drawing tools (such as pen, pencil or crayon on smooth or rough paper) and the other of which drew on abstract descriptors of haptic experience (roughness, stickiness, scratchiness and smoothness). It was found that users valued having control over the haptic sensation; that each metaphor was preferred by approximately half of the participants; and that the real world metaphor interface was considered more helpful than the abstract one, whereas the abstract interface was considered to better support creativity. This suggests that future interfaces for artistic work should have user-modifiable interaction styles for controlling the haptic sensation

InfoVis experience enhancement through mediated interaction

Information visualization is an experience in which both the aesthetic representations and interaction are part. Such an experience can be augmented through close consideration of its major components. Interaction is crucial to the experience, yet it has seldom been adequately explored in the field. We claim that direct mediated interaction can augment such an experience. This paper discusses the reasons behind such a claim and proposes a mediated interactive manipulation scheme based on the notion of directness. It also describes the ways in which such a claim will be validated. The Literature Knowledge Domain (LKD) is used as the concrete domain around which the discussions will be held

Challenges of evaluating the information visualization experience

Information Visualisation (InfoVis) is defined as an interactive visual representation of abstract data. We view the user’s interaction with InfoVis tools as an experience which is made up of a set of highly demanding cognitive activities. These activities assist users in making sense and gaining knowledge of the represented domain. Usability studies that involve a task-based analysis and usability questionnaires are not enough to capture such an experience. This paper discusses the challenges involved when it comes to evaluating InfoVis tools by giving an overview of the activities involved in an InfoVis experience and demonstrating how they affect the visualisation process. The argument in this paper is based on our experiences in designing, building and evaluating an academic literature visualisation tool

Intrinsic Variability and Field Statistics for the Vela Pulsar: 3. Two-Component Fits and Detailed Assessment of Stochastic Growth Theory

The variability of the Vela pulsar (PSR B0833-45) corresponds to well-defined field statistics that vary with pulsar phase, ranging from Gaussian intensity statistics off-pulse to approximately power-law statistics in a transition region and then lognormal statistics on-pulse, excluding giant micropulses. These data are analyzed here in terms of two superposed wave populations, using a new calculation for the amplitude statistics of two vectorially-combined transverse fields. Detailed analyses show that the approximately power-law and lognormal distributions observed are fitted well at essentially all on-pulse phases by Gaussian-lognormal and double-lognormal combinations, respectively. These good fits, plus the smooth but significant variations in fit parameters across the source, provide strong evidence that the approximately power-law statistics observed in the transition region are not intrinsic. Instead, the data are consistent with normal pulsar emission having lognormal statistics at all phases. This is consistent with generation in an inhomogeneous source obeying stochastic growth theory (SGT) and with the emission mechanism being purely linear (either direct or indirect). A nonlinear mechanism is viable only if it produces lognormal statistics when suitably ensemble-averaged. Variations in the SGT fit parameters with phase imply that the radiation is relatively more variable near the pulse edges than near the center, as found in earlier work. In contrast, Vela's giant micropulses come from a very restricted phase range and have power-law statistics with indices ($6.7 \pm 0.6$) not inconsistent with nonlinear wave collapse. These results imply that normal pulses have a different source and generation mechanism than giant micropulses, as suggested previously on other grounds.Comment: 10 pages and 14 figures. Accepted by Monthly Notices of the Royal Astronomical Society in April 200

Intrinsic Variability and Field Statistics for the Vela Pulsar: 2. Systematics and Single-Component Fits

Individual pulses from pulsars have intensity-phase profiles that differ widely from pulse to pulse, from the average profile, and from phase to phase within a pulse. Widely accepted explanations do not exist for this variability or for the mechanism producing the radiation. The variability corresponds to the field statistics, particularly the distribution of wave field amplitudes, which are predicted by theories for wave growth in inhomogeneous media. This paper shows that the field statistics of the Vela pulsar (PSR B0833-45) are well-defined and vary as a function of pulse phase, evolving from Gaussian intensity statistics off-pulse to approximately power-law and then lognormal distributions near the pulse peak to approximately power-law and eventually Gaussian statistics off-pulse again. Detailed single-component fits confirm that the variability corresponds to lognormal statistics near the peak of the pulse profile and Gaussian intensity statistics off-pulse. The lognormal field statistics observed are consistent with the prediction of stochastic growth theory (SGT) for a purely linear system close to marginal stability. The simplest interpretations are that the pulsar's variability is a direct manifestation of an SGT state and the emission mechanism is linear (either direct or indirect), with no evidence for nonlinear mechanisms like modulational instability and wave collapse which produce power-law field statistics. Stringent constraints are placed on nonlinear mechanisms: they must produce lognormal statistics when suitably ensemble-averaged. Field statistics are thus a powerful, potentially widely applicable tool for understanding variability and constraining mechanisms and source characteristics of coherent astrophysical and space emissions.Comment: 11 pages, 12 figures. Accepted by Monthly Notices of the Royal Astronmical Society in April 200

Smarter choices ?changing the way we travel. Case study reports

This report accompanies the following volume:Cairns S, Sloman L, Newson C, Anable J, Kirkbride A and Goodwin P (2004)Smarter Choices ? Changing the Way We Travel. Report published by theDepartment for Transport, London, available via the ?Sustainable Travel? section ofwww.dft.gov.uk, and from http://eprints.ucl.ac.uk/archive/00001224/

Smarter choices - changing the way we travel

Summary: In recent years, there has been growing interest in a range of initiatives, which are now widelydescribed as 'soft' transport policy measures. These seek to give better information and opportunities,aimed at helping people to choose to reduce their car use while enhancing the attractiveness ofalternatives. They are fairly new as part of mainstream transport policy, mostly relativelyuncontroversial, and often popular. They include:. Workplace and school travel plans;. Personalised travel planning, travel awareness campaigns, and public transport information andmarketing;. Car clubs and car sharing schemes;. Teleworking, teleconferencing and home shopping.This report draws on earlier studies of the impact of soft measures, new evidence from the UK andabroad, case study interviews relating to 24 specific initiatives, and the experience of commercial,public and voluntary stakeholders involved in organising such schemes. Each of the soft factors isanalysed separately, followed by an assessment of their combined potential impact.The assessment focuses on two different policy scenarios for the next ten years. The 'high intensity'scenario identifies the potential provided by a significant expansion of activity to a much morewidespread implementation of present good practice, albeit to a realistic level which still recognisesthe constraints of money and other resources, and variation in the suitability and effectiveness of softfactors according to local circumstances. The 'low intensity' scenario is broadly defined as aprojection of the present (2003-4) levels of local and national activity on soft measures.The main features of the high intensity scenario would be. A reduction in peak period urban traffic of about 21% (off-peak 13%);. A reduction of peak period non-urban traffic of about 14% (off-peak 7%);. A nationwide reduction in all traffic of about 11%.These projected changes in traffic levels are quite large (though consistent with other evidence onbehavioural change at the individual level), and would produce substantial reductions in congestion.However, this would tend to attract more car use, by other people, which could offset the impact ofthose who reduce their car use unless there are measures in place to prevent this. Therefore, thoseexperienced in the implementation of soft factors locally usually emphasise that success depends onsome or all of such supportive policies as re-allocation of road capacity and other measures toimprove public transport service levels, parking control, traffic calming, pedestrianisation, cyclenetworks, congestion charging or other traffic restraint, other use of transport prices and fares, speedregulation, or stronger legal enforcement levels. The report also records a number of suggestionsabout local and national policy measures that could facilitate the expansion of soft measures.The effects of the low intensity scenario, in which soft factors are not given increased policy prioritycompared with present practice, are estimated to be considerably less than those of the high intensityscenario, including a reduction in peak period urban traffic of about 5%, and a nationwide reductionin all traffic of 2%-3%. These smaller figures also assume that sufficient other supporting policies areused to prevent induced traffic from eroding the effects, notably at peak periods and in congestedconditions. Without these supportive measures, the effects could be lower, temporary, and perhapsinvisible.Previous advice given by the Department for Transport in relation to multi-modal studies was that softfactors might achieve a nationwide traffic reduction of about 5%. The policy assumptionsunderpinning this advice were similar to those used in our low intensity scenario: our estimate isslightly less, but the difference is probably within the range of error of such projections.The public expenditure cost of achieving reduced car use by soft measures, on average, is estimated atabout 1.5 pence per car kilometre, i.e. £15 for removing each 1000 vehicle kilometres of traffic.Current official practice calculates the benefit of reduced traffic congestion, on average, to be about15p per car kilometre removed, and more than three times this level in congested urban conditions.Thus every £1 spent on well-designed soft measures could bring about £10 of benefit in reducedcongestion alone, more in the most congested conditions, and with further potential gains fromenvironmental improvements and other effects, provided that the tendency of induced traffic to erodesuch benefits is controlled. There are also opportunities for private business expenditure on some softmeasures, which can result in offsetting cost savings.Much of the experience of implementing soft factors is recent, and the evidence is of variable quality.Therefore, there are inevitably uncertainties in the results. With this caveat, the main conclusion isthat, provided they are implemented within a supportive policy context, soft measures can besufficiently effective in facilitating choices to reduce car use, and offer sufficiently good value formoney, that they merit serious consideration for an expanded role in local and national transportstrategy.AcknowledgementsWe gratefully acknowledge the many contributions made by organisations and individuals consultedas part of the research, and by the authors of previous studies and literature reviews which we havecited. Specific acknowledgements are given at the end of each chapter.We have made extensive use of our own previous work including research by Lynn Sloman funded bythe Royal Commission for the Exhibition of 1851 on the traffic impact of soft factors and localtransport schemes (in part previously published as 'Less Traffic Where People Live'); and by SallyCairns and Phil Goodwin as part of the research programme of TSU supported by the Economic andSocial Research Council, and particularly research on school and workplace travel plans funded bythe DfT (and managed by Transport 2000 Trust), on car dependence funded by the RAC Foundation,on travel demand analysis funded by DfT and its predecessors, and on home shopping funded byEUCAR. Case studies to accompany this report are available at: http://eprints.ucl.ac.uk/archive/00001233

The rise of a native sun coral species on southern Caribbean coral reefs

In contrast with a general decline of Caribbean reef corals, a previously rare sun coral is increasing in abundance within shallow coral communities on Curaçao. This azooxanthellate scleractinian was identified as Cladopsammia manuelensis, which has an amphi‐Atlantic distribution. Over the last decade, C. manuelensis has increased abundance along the leeward coast of Curaçao (southern Caribbean) between depths of 4 and 30 m. This species was initially not noticed because it resembles the invasive coral Tubastraea coccinea, which was introduced to Curaçao from the Indo‐Pacific around 1940. However, in contrast to T. coccinea, C. manuelensis was previously only present on deeper reef sections (>70 m) of Caribbean reefs. Our observations illustrate how the sudden increase in abundance of a previously unnoticed, apparently cryptogenic species could result from natural dynamics on present‐day reefs, but also could easily be mistaken for an invasive species. The finding that deep reef sections can harbor species capable of colonizing shallower reef zones highlights the importance of thorough inventories of reef communities across large depth ranges, which can help us to discriminate between range increases of native species and the arrival of invasives

Pole Dancing: 3D Morphs for Tree Drawings

We study the question whether a crossing-free 3D morph between two straight-line drawings of an $n$-vertex tree can be constructed consisting of a small number of linear morphing steps. We look both at the case in which the two given drawings are two-dimensional and at the one in which they are three-dimensional. In the former setting we prove that a crossing-free 3D morph always exists with $O(\log n)$ steps, while for the latter $\Theta(n)$ steps are always sufficient and sometimes necessary.Comment: Appears in the Proceedings of the 26th International Symposium on Graph Drawing and Network Visualization (GD 2018