Understanding multitasking through parallelized strategy exploration and individualized cognitive modeling

Human multitasking often involves complex task interactions and subtle tradeoffs which might be best understood through detailed computational cognitive modeling, yet traditional cognitive modeling approaches may not explore a sufficient range of task strategies to reveal the true complexity of multitasking behavior. This study proposes a systematic approach for exploring a large number of strategies using a computer-cluster-based parallelized modeling system. The paper demonstrates the efficacy of the approach for investigating and revealing the effects of different microstrategies on human performance, both within and across individuals, for a time-pressured multimodal dual task. The modeling results suggest that multitasking performance is not simply a matter of interleaving cognitive and sensorimotor processing but is instead heavily influenced by the selection of subtask microstrategies. Author Keywords Cognitive modeling; high performance computing; mode

The Emergence of Interactive Behaviour: A Model of Rational Menu Search

ABSTRACT One reason that human interaction with technology is difficult to understand is because the way in which people perform interactive tasks is highly adaptive. One such interactive task is menu search. In the current article we test the hypothesis that menu search is rationally adapted to (1) the ecological structure of interaction, (2) cognitive and perceptual limits, and (3) the goal to maximise the trade-off between speed and accuracy. Unlike in previous models, no assumptions are made about the strategies available to or adopted by users, rather the menu search problem is specified as a reinforcement learning problem and behaviour emerges by finding the optimal policy. The model is tested against existing empirical findings concerning the effect of menu organisation and menu length. The model predicts the effect of these variables on task completion time and eye movements. The discussion considers the pros and cons of the modelling approach relative to other well-known modelling approaches

The Emergence of Interactive Behaviour: A Model of Rational Menu Search

ABSTRACT One reason that human interaction with technology is difficult to understand is because the way in which people perform interactive tasks is highly adaptive. One such interactive task is menu search. In the current article we test the hypothesis that menu search is rationally adapted to (1) the ecological structure of interaction, (2) cognitive and perceptual limits, and (3) the goal to maximise the trade-off between speed and accuracy. Unlike in previous models, no assumptions are made about the strategies available to or adopted by users, rather the menu search problem is specified as a reinforcement learning problem and behaviour emerges by finding the optimal policy. The model is tested against existing empirical findings concerning the effect of menu organisation and menu length. The model predicts the effect of these variables on task completion time and eye movements. The discussion considers the pros and cons of the modelling approach relative to other well-known modelling approaches

Evaluation of a surgical interface for robotic cryoablation task using an eye-tracking system

Computer-assisted navigation systems coupled with surgical interfaces (SIs) are providing doctors with tools that are safer for patients compared to traditional methods. Usability analysis of the SIs that guides their development is hence important. In this study, we record the eye movements of doctors and other people with no medical expertise during interaction with an SI that directs a simulated cryoablation task. There are two different arrangements for the layout of the same SI, and the goal is to evaluate whether one of these arrangements is ergonomically better than the other. We use several gaze related statistics some of which are employed in an SI design context for the first time. Even though the performance and gaze related analysis reveals that the two arrangements are comparable in many respects, there are also differences. Specifically, one arrangement leads to more saccades along the vertical and horizontal directions, lower saccade amplitudes in the crucial phase of the task, more locally clustered and yet globally spread viewing. Accordingly, that arrangement is selected for future use. The present study provides a proof of concept for the integration of novel gaze analysis tools developed for scene perception studies into the interface development process.European Commissionpost-prin

Metrics and Tools to Guide Design of Graphical User Interfaces

User interface design metrics assist developers evaluate interface designs in early phase before delivering the software to end users. This dissertation presents a metric-based tool called GUIEvaluator for evaluating the complexity of the user interface based on its structure. The metrics-model consists of five modified structural measures of interface complexity: Alignment, grouping, size, density, and balance. The results of GUIEvaluator are discussed in comparison with the subjective evaluations of interface layouts and the existing complexity metrics-models. To extend this metrics-model, the Screen-Layout Cohesion (SLC) metric has been proposed. This metric is used to evaluate the usability of user interfaces. The SLC metric has been developed based on Aesthetic, structural, and semantic aspects of GUIs. To provide the SLC calculation, a complementary tool has been developed, which is called GUIExaminer. This dissertation demonstrates the potential of incorporating automated complexity and cohesion metrics into the user interface design process. The findings show that a strong positive correlation between the subjective evaluation and both the GUIEvaluator and GUIExaminer, at a significance level 0.05. Moreover, the findings provide evidence of the effectiveness of the GUIEvaluator and GUIExaminer to predict the best user interface design among a set of alternative user interfaces. In addition, the findings show that the GUIEvaluator and GUIExaminer can measure some usability aspects of a given user interface. However, the metrics validation proves the usefulness of GUIEvaluator and GUIExaminer for evaluating user interface designs