1,721,009 research outputs found
What makes an interruption disruptive? Understanding the effects of interruption relevance and timing on performance
Get PDFInterruptions disrupt activity, hindering performance and provoking errors. They present an obvious challenge in safety-critical environments where momentary slips can have fatal consequences. Interruptions are also a problem in more workaday settings, like offices, where they can reduce productivity and increase stress levels. To be able to systematically manage the negative effects of interruptions, we first need to understand the factors that influence their disruptiveness. This thesis explores how the disruptiveness of interruptions is influenced by their relevance and timing. Seven experimental studies investigate these properties in the context of a routine data-entry task. The first three experiments explore how relevance and timing interact. They demonstrate that the relevance of interruptions depends on the contents of working memory at the moment of interruption. Next, a pair of experiments distinguish the oft-conflated concepts of interruption relevance and relatedness. They show that interruptions with similar content to the task at hand can negatively affect performance if they do not contribute toward the rehearsal of goals in working memory. By causing active interference, seemingly useful interruptions that are related to the task at hand have the potential to be more disruptive than entirely unrelated, irrelevant interruptions. The final two experiments in this thesis test the reliability of the effects observed in the first five experiments through alternative experimental paradigms. They show that relevance and timing effects are consistent even when participants are given control over interruptions and that these effects are robust even in an online setting where experimental control is compromised. The work presented in this thesis enhances our understanding of the factors influencing the disruptiveness of interruptions. Its primary contribution is to show that when we talk about interruptions, ‘relevance’, ‘irrelevance’ and ‘relatedness’ must be considered in the context of the contents of working memory at the moment of interruption. This finding has implications for experimental investigations of interrupted performance, efforts to under- stand the effects of interruptions in the workplace, and the development of systems that help users manage interruptions
Designing for Numerical Transcription Typing: Frequent Numbers Matter
Get PDFIn the text entry domain, the task of number entry is often overlooked despite the prevalence of number entry tasks in the real world. Number entry often occurs in safety critical contexts, such as the medical domain, where errors can lead to patient death. In order to prevent errors from happening, it is important to design devices that help the user in their number entry task, and guard against error. To do this effectively, more needs to be known about the task of number transcription so that appropriate design interventions can be created. Current research commonly uses randomly generated numbers in the evaluation of number entry interfaces. However, it is not clear that random numbers are appropriate in this context. The first half of the thesis builds on research that shows that the familiarity of a number can affect how it is read, and investigates how this finding impacts upon transcription of familiar numbers. This is investigated by replicating seminal transcription typing studies using both words and numbers. The results of these experiments suggest that familiar numbers are represented more strongly than non-familiar numbers in memory, and as a result familiar numbers are significantly faster to transcribe. This novel finding then motivates a series of studies that aim to reduce errors in a medical number entry task. First, a log analysis of hospital devices shows that there are clear patterns in the numbers used, providing evidence that medical workers are likely to be more familiar with some numbers rather than others. The knowledge of these frequently used numbers is then utilised in three novel approaches to number entry interface design. First, knowledge of the landscape of frequent numbers in this context is used to create a set of heuristics for the design of number entry interfaces. Second, an experiment shows that adapting the interface specifically for frequent number entry can speed up interaction. Finally an experiment explores how an understanding of the numbers used to program devices can be used to check for and prevent number transcription errors. This thesis highlights the importance of understanding the frequency and familiarity of num- bers used in specific contexts. It explores how this knowledge can improve both evaluation and design of number entry interfaces
Detecting errors in pick and place procedures
Get PDFMany human activities, such as manufacturing and assembly, are sequence-constrained procedural tasks (SPTs): they consist of a series of steps that must be executed in a specific spatial/temporal order. However, these tasks can be error prone - steps can be missed out, executed out-of-order, and repeated. The ability to automatically predict if a person is about to commit an error could greatly help in these cases. The prediction could be used, for example, to provide feedback to prevent mistakes or mitigate their effects. In this paper, we present a novel approach for real-time error prediction for multi-step sequence tasks which uses a minimum viable set of behavioural signals. We have three main contributions. The first we present an architecture for real-time error prediction based on task tracking and intent prediction. The second is to explore the effectiveness of using hand position and eye-gaze tracking for task tracking. We confirm that eye-gaze is more effective for intent prediction, hand tracking is more accurate for task tracking and that combining the two provides the best overall response. We show that using Hands and Gaze tracking data we can predict selection/placement errors with an F1 score of 97%, approximately 300ms before the error would occur. Finally, we discuss the application of this hand-gaze error detection architecture used in conjunction with head-mounted AR displays, to support industrial manual assembly
Using visual and auditory cues to locate out-of-view objects in head-mounted augmented reality
Get PDFWhen looking for an object in a complex visual scene, Augmented Reality (AR) can assist search with visual cues persistently pointing in the target's direction. The effectiveness of these visual cues can be reduced if they are placed at a different visual depth plane to the target they are indicating. To overcome this visual-depth problem, we test the effectiveness of adding simultaneous spatialized auditory cues that are fixed at the target's location. In an experiment we manipulated which cue(s) were available (visual-only vs. visual + auditory), and which disparity plane relative to the target the visual cue was displayed on. Results show that participants were slower at finding targets when the visual cue was placed on a different disparity plane to the target. However, this slowdown in search performance could be substantially reduced with auditory cueing. These results demonstrate the importance of AR cross-modal cueing under conditions of visual uncertainty and show that designers should consider augmenting visual cues with auditory ones
Understanding Strategic Adaptation in Dual-Task Situations as Cognitively Bounded Rational Behavior
Get PDFIn this thesis I explored when people interleave attention in dual-task settings. The hypothesis is that people try to perform in a cognitively bounded rational way. Performance is limited by constraints that come from the task environment and cognition. If, given these constraints, multiple strategies for interleaving tasks are available, then people will interleave tasks in a way that aligns with their local priority objective (Chapter 3), or which maximizes the value of an objective payoff function that evaluates performance (Chapter 4). This hypothesis was tested using a combination of experimental studies and computational cognitive models. Across a series of studies, the interplay between different constraints was investigated. In Chapters 5 and 6, I developed mathematical models to study what task combinations in general allowed for “ideal payoff manipulations” to study task interleaving. The work contributed to the existing literature in four ways: (1) it provided an overarching theory of skilled human dual-task performance and tested this in relatively applied settings, (2) the theory was formalized in computational cognitive models that can predict performance of unobserved strategies and that can bracket the (optimal) performance space, (3) linear and logarithmic tasks were identified as an ideal combination for achieving ideal payoff manipulations, and (4) results demonstrated that in multitasking situations attention is not necessarily interleaved solely at chunk boundaries and other “natural breakpoints”, but that this depends on a person’s priorities. The work has implications for driver distraction research, in that it helps in systematically understanding the performance trade-offs that people face when multitasking. Moreover, the modeling framework could be used for model-based evaluation of new mobile interfaces. Finally, the demonstration that priorities can strongly influence multitasking performance highlights the importance of public safety campaigns that emphasize awareness of driver safety. Limitations and further implications are discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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