Identifying the Contributors of Intrinsic, Extraneous, and Germane Load in Human-Robot Collaboration Through Interview Questions

A significant challenge in human-robot collaboration (HRC) is managing the emergent cognitive workload of the human operator. Human-robot collaboration (HRC) relies on communication, decision-making, planning, coordination, situational awareness, and error handling. These cognitive processes can lead to complex tasks for operators and increased workload, which can negatively impact the HRC effectiveness. Current research in HRC focuses on understanding and quantifying the cognitive workload imposed during the task utilizing objective and subjective measures. Objective and subjective measures can identify cognitive workload states. However, these measures cannot distinguish the specific influence of each workload type (intrinsic, extraneous, and germane) on cognitive workload. The intrinsic workload is affected by the task’s difficulty and is influenced by the information needed to be processed and the user’s existing knowledge. Extraneous workload represents the cognitive effort imposed by environmental, instructional, and presentation factors. For example, distractions, irrelevant information, confusing guidance, or information during the task can lead to an extraneous workload. Germene load refers to the cognitive effort required to process and integrate new information into long-term memory. The cognitive processes involved include information organization, connecting task demands to prior knowledge, and constructing mental models to grasp complex concepts. Each cognitive workload type uniquely contributes to cognitive processing; therefore, assessing them is important for understanding workload dynamics and optimizing task design in HRC. To better understand the effect of each workload type on cognitive load, we conducted a human-subject study where participants completed a collaborative task with a robot under low and high cognitive workload states. At the end of the task, participants completed a semi-structured interview. On performing a qualitative analysis of participants' responses, we identified key factors and themes associated with each type of cognitive load. The intrinsic workload was primarily affected by three factors: the robot's speed, the need to multitask, and the learning curve associated with the robot's navigation and design. Regarding the extraneous workload, a central theme was the robot's speed, which triggered distractions for the operator. Finally, the germane load was characterized by the following themes: acquiring knowledge, performing HRC tasks, and enhancing multitasking capabilities such as hand-eye coordination. These results highlight that different aspects of robot design, task design, and task execution contribute uniquely to the overall cognitive workload.