Adam J. Strang

Conceptualization and Measurement of Team Workload A Critical Need

Objective: The purpose of this article is to present and expand on current theories and measurement techniques for assessing team workload. Background: To date, little research has been conducted on the workload experienced by teams. A validated theory describing team workload, which includes an account of its relation to individual workload, has not been articulated. Method: The authors review several theoretical approaches to team workload. Within the team research literature, attempts to evaluate team workload have typically relied on measures of individual workload. This assumes that such measures retain their validity at the team level of measurement, but empirical research suggests that this method may lack sensitivity to the drivers of team workload. Results: On the basis of these reviews, the authors advance suggestions concerning a comprehensive theory of team workload and methods for assessing it in team settings. The approaches reviewed include subjective, performance, physiological, and strategy shift measures. Theoretical and statistical difficulties associated with aggregating individual-level workload responses to a team-level measure are discussed. Conclusion: Conception and measurement of team workload have not significantly matured alongside developments in individual workload. Application: Team workload remains a complex research area without simple measurement solutions, but as a research domain it remains open for contributions from interested and enterprising researchers.

Recurrence Quantification Analysis Used to Assess Team Communication in Simulated Air Battle Management

Nonlinear time-series measures provide an opportunity to examine temporal structure in team communications. In this experiment, Recurrence Quantification Analysis (RQA), a nonlinear measure that quantifies visual patterns in recurrence plots, was applied to verbal communication utterances produced in a 5-person air defense simulation. Communication utterances were analyzed with three coding schemes – team position, semantic content, and combined. No differences in RQA percent determinism (%DET) driven by experimental manipulations were detected for communications coded by team position, but differences were detected for semantic content and combined. This implies that a higher resolution of coding was necessary to detect manipulated effects via RQA in this experiment. Specific changes in %DET, when paired with findings from a more traditional communication analysis, i.e., cumulative frequency, indicated positive compensatory adaptations in team communication when faced with training and task constraints. Results are discussed with emphasis on changes in %DET as a result of current experimental manipulations and integration with previous research.

Collaboration technologies improve performance and communication in air battle management.

Team communication is critical for Air Battle Management (ABM). In this study, two communication tools (text chat and electronic whiteboard) and two team resource aids (tabular and graphical displays) were introduced during simulated ABM to supplement radio communication. Results showed that combined chat and virtual whiteboard improved team performance, decreased number and duration of radio transmissions, but had mixed effects on workload. In addition, the graphical resource display improved team performance, decreased number and duration of radio transmissions, and reduced workload compared to the tabular display. These findings indicate that collaboration technologies introduced in this experiment may benefit military operations.

Human Factors of Cyber Attacks A Framework for Human-Centered Research

Cyber security has been a growing focus within the human factors community. Over the last several years, human-centered cyber research has provided valuable insights into the cognitive and collaborative work within cyber operations, but has largely ignored how the genesis, intentions, methods and outcomes of cyber attacks impact human-related outcomes. Leveraging insights from other, more technologically focused communities, the goal of this paper is to synthesize previous work and to present a unified, descriptive framework of cyber attacks. Our framework, which consists of three dimensions, adversarial, methodological, and operational, aims to maintain the rich interactions between the components of a cyber attack while offering a further abstraction useful to future human factors research. We present each dimension in terms of the previous techno-centered research, demonstrate how the human factors community can contribute to our understanding, and ground each within the context of the StuxNet virus.

Examining Temporal Regularity in Categorical Team Communication Using Sample Entropy

Communication is inherent to team coordination and performance. Nonlinear time-series measures, such as Sample Entropy (SEn), provide the opportunity to examine the temporal structure of team communication. The aim for this experiment was to develop a method for applying SEn to a set of categorically coded and sequential team verbal communications recorded during a dyadic Air Battle Management (ABM) simulation. Results showed that deterministic temporal regularity was detected in team communication for three categorical coding schemes applied to the data – team role, semantic content, and combined. For data coded for semantic content, SEn was able to detect an increase in communication temporal regularity for teams exposed to high workload. Practical and theoretical implications are considered.

Evaluation of Subjective and EEG-Based Measures of Mental Workload

Assessment of mental workload is an important aspect of many human factors and HCI applications. Not surprisingly, a number of workload measures have been proposed. This study examined the sensitivity, convergent and concurrent validity of several subjective self-report and EEG workload measures. Most measures displayed adequate sensitivity to task difficulty manipulations, but relatively modest convergent and concurrent validity. Overall, we believe these result serve to aid human factors practitioners in selecting measures of workload for varied applications.

Physio-behavioral Synchronicity as an Index of Processes Supporting Team Performance

Recent research suggests that synchronicity in physiological and behavioral responses during team tasks could provide an objective measure of processes underlying team performance. In this study, twenty dyads completed a series of trials in a variant of video game Tetris (Quadra). Task performance was divided between the participants such that they had to work interdependently to succeed. Team-paired cardiac interbeat intervals (IBIs) and postural sway (anterior-posterior head motion) were analyzed using Cross-Sample Entropy (CSEn) as indices of physiobehavioral synchronicity. Quantity of team verbal communication (number of words spoken) and a survey measure of team cohesion were also assessed. An increase in team performance was found to be associated with a decrease in IBI synchronicity, while an increase in team verbal communication was related to both an in increase postural sway synchronicity and team cohesion. Overall, this research supports the assertion that metrics of team synchronicity may serve as useful surrogate indices of team processes and performance.

Super-Absorbent Polymer Valves and Colorimetric Chemistries for Time-Sequenced Discrete Sampling and Chloride Analysis of Sweat via Skin-Mounted Soft Microfluidics

This paper introduces super absorbent polymer valves and colorimetric sensing reagents as enabling components of soft, skin-mounted microfluidic devices designed to capture, store, and chemically analyze sweat released from eccrine glands. The valving technology enables robust means for guiding the flow of sweat from an inlet location into a collection of isolated reservoirs, in a well-defined sequence. Analysis in these reservoirs involves a color responsive indicator of chloride concentration with a formulation tailored to offer stable operation with sensitivity optimized for the relevant physiological range. Evaluations on human subjects with comparisons against ex situ analysis illustrate the practical utility of these advances.

Capturing Performance in Cyber Human Supervisory Control

Modern cyber operations require operators to maintain supervisory control of remote computer agents. A current operational concern is the number of agents an operator can control at once. This type of task resonates with similar Human Supervisory Control (HSC) research that has been conducted in environments such as Unmanned Aerial Vehicle operations. Within the relevant literature, there has been limited discussion of cyber-HSC, and no available experimental research. In this paper, we present an initial exploration cyber-HSC. Using the BOARD 1.5 Simulation, we manipulated the number of autonomous assets accessible to a human operator. We expected that as the number of autonomous agents available increased, we would observe concomitant changes in human performance and cognition.However, our results indicated that participants’ overall span-of-control did not vary with additional agents. Our findings highlight the need for continued research on issues of supervisory control within cyber operations.

Heart Rate Correlates of Mental Workload in a Large-Scale Air-Combat Simulation Training Exercise

Automated and real-time measures of mental workload (MW) may benefit scenario management, performance assessment and feedback during simulation training. Heart rate (HR) metrics show promise as surrogates of MW and thus, could provide a basis for the development of such tools. The goal for this study was to explore the relationship between HR metrics and MW in operators during large-scale, multi-team, simulated air-combat missions. A number of significant correlations between HR metrics and MW were identified, all of which exhibited trends consistent with previous research. However, the relationships between HR metrics and MW ratings were different across different task roles, suggesting that individual differences and/or task-specific demands may be important for determining the HR metrics to serve as surrogates of MW in future real-time assessment. Finally, hierarchical linear regression demonstrated that collectively, HR metrics were predictive of MW, even with individual differences and repeated measures effects accounted for in the model. This implies that HR metrics are viable sources of information from which to build predictive MW models for operators performing command and control (C2) tasks.