Multiple paths in complex tasks

The relationship between utility judgments of subtask paths and the utility of the task as a whole was examined. The convergent validation procedure is based on the assumption that measurements of the same quantity done with different methods should covary. The utility measures of the subtasks were obtained during the performance of an aircraft flight controller navigation task. Analyses helped decide among various models of subtask utility combination, whether the utility ratings of subtask paths predict the whole tasks utility rating, and indirectly, whether judgmental models need to include the equivalent of cognitive noise

"Narco" Emotions: Affect and Desensitization in Social Media during the Mexican Drug War

Social media platforms have emerged as prominent information sharing ecosystems in the context of a variety of recent crises, ranging from mass emergencies, to wars and political conflicts. We study affective responses in social media and how they might indicate desensitization to violence experienced in communities embroiled in an armed conflict. Specifically, we examine three established affect measures: negative affect, activation, and dominance as observed on Twitter in relation to a number of statistics on protracted violence in four major cities afflicted by the Mexican Drug War. During a two year period (Aug 2010-Dec 2012), while violence was on the rise in these regions, our findings show a decline in negative emotional expression as well as a rise in emotional arousal and dominance in Twitter posts: aspects known to be psychological markers of desensitization. We discuss the implications of our work for behavioral health, facilitating rehabilitation efforts in communities enmeshed in an acute and persistent urban warfare, and the impact on civic engagement.Comment: Best paper award at the 32nd annual ACM conference on Human factors in computing systems (CHI '14). ACM, New York, NY, USA, pages 3563-357

An Empirical Study Comparing Unobtrusive Physiological Sensors for Stress Detection in Computer Work.

Several unobtrusive sensors have been tested in studies to capture physiological reactions to stress in workplace settings. Lab studies tend to focus on assessing sensors during a specific computer task, while in situ studies tend to offer a generalized view of sensors' efficacy for workplace stress monitoring, without discriminating different tasks. Given the variation in workplace computer activities, this study investigates the efficacy of unobtrusive sensors for stress measurement across a variety of tasks. We present a comparison of five physiological measurements obtained in a lab experiment, where participants completed six different computer tasks, while we measured their stress levels using a chest-band (ECG, respiration), a wristband (PPG and EDA), and an emerging thermal imaging method (perinasal perspiration). We found that thermal imaging can detect increased stress for most participants across all tasks, while wrist and chest sensors were less generalizable across tasks and participants. We summarize the costs and benefits of each sensor stream, and show how some computer use scenarios present usability and reliability challenges for stress monitoring with certain physiological sensors. We provide recommendations for researchers and system builders for measuring stress with physiological sensors during workplace computer use

Boundary Objects in Design: An Ecological View of Design Artifacts

Traditionally, Systems Analysis and Design (SAD) research has focused on ways of working and ways of modeling. Design ecology – the task, organizational and political context surrounding design – is less well understood. In particular, relationships between design routines and products within ecologies have not received sufficient attention. In this paper, we theorize about design product and ecology relationships and deliberate on how design products – viewed as boundary objects – bridge functional knowledge and stakeholder power gaps across different social worlds. We identify four essential features of design boundary objects: capability to promote shared representation, capability to transform design knowledge, capability to mobilize for action, and capability to legitimize design knowledge. We show how these features help align, integrate, and transform heterogeneous technical and domain knowledge across social worlds as well as mobilize, coordinate, and align stakeholder power. We illustrate through an ethnography of a large aerospace laboratory how two design artifacts – early proto-architectures and project plans – shared these four features to coalesce design processes and propel successful movement of designs across social worlds. These artifacts resolved uncertainty associated with functional requirements and garnered political momentum to choose among design solutions. Altogether, the study highlights the importance of design boundary objects in multi-stakeholder designs and stresses the need to formulate sociology-based design theories on how knowledge is produced and consumed in complex SAD tasks

Reflecting upon perceptual speed tests in information retrieval : limitations, challenges, and recommendations

Perceptual Speed (PS) is a cognitive ability defined by an individual’s accuracy and speed to scan information while completing visual search tasks. Prior studies using PS tests have demonstrated that PS affects multiple factors in Information Retrieval (IR), such as a user’s search performance, interaction with the system, time spent completing tasks, and subjective impression of their workload. With greater knowledge of PS, systems could be designed that accommodate users with low PS to improve their overall search experience. However, in this perspectives paper, we analyse how PS tests have been used in IR, and identify multiple uncertainties regarding PS content, administration, analysis, and reporting of findings. Consequently, we aim to stir discussion between IR researchers by drawing awareness to these issues. As a result, we further discuss challenges involved in advancing how future PS tests are used in IR. Finally, we propose recommendations that have the potential for enhancing the reliability and validity of current PS tests