Level of automation effects on performance, situation awareness and workload in a dynamic control task

Abstract

Various levels of automation (LOA) designating the degree of human operator and computer control were explored within the context of a dynamic control task as a means of improving overall human/machine performance. Automated systems have traditionally been explored as binary function allocations; either the human or the machine is assigned to a given task. More recently, intermediary levels of automation have been discussed as a means of maintaining operator involvement in system performance, leading to improvements in situation awareness and reductions in out-of-the-loop performance problems. A LOA taxonomy applicable to a wide range of psychomotor and cognitive tasks is presented here. The taxonomy comprises various schemes of generic control system function allocations. The functions allocated to a human operator and/or computer included monitoring displays, generating processing options, selecting an`optimal' option and implementing that option. The impact of the LOA taxonomy was assessed within a dynamic and complex cognitive control task by measuring its eOE ect on human/system performance, situation awareness and workload. Thirty subjects performed simulation trials involving various levels of automation. Several automation failures occurred and out-of-the-loop performance decrements were assessed. Results suggest that, in terms of performance, human operators bene® t most from automation of the implementation portion of the task, but only under normal operating conditions; in contrast, removal of the operator from task implementation is detrimental to performance recovery if the automated system fails. Joint human/system option generation signi® cantly degraded performance in comparison to human or automated option generation alone. Lower operator workload and higher situation awareness were observed under automation of the decision making portion of the task (i.e. selection of options), although human/system performance was only slightly improved. The implications of these ® ndings for the design of automated systems are discussed.

The effects of level of automation and adaptive automation on human performance, situation awareness and workload in a dynamic control task

“…Kaber et al (2000) studied six of the LOAs presented in Endsley and Kaber's (1999) taxonomy, including Manual Control (LOA 1), Action Support (LOA 2), Batch Processing (LOA 3), Decision Support (LOA 5), Supervisory Control (LOA 9) and Full Automation (LOA 10), representing the range of LOAs found to impact Multitask # performance. Results indicated that higher LOAs led to improved performance in terms of time-to-task completion and number of errors committed under normal conditions.…”

“…Rather it can be applied to different aspects of a task in varying degrees, creating different levels of task auton- Figure 1. Approaches to human-centred automation (from Endsley 1996). omy (Endsley and Kaber 1999). A number of different taxonomies or hierarchies of LOA have been developed.…”

Impact of automation: Measurement of performance, workload and behaviour in a complex control environment

“…None of the other existing definitions of levels (e.g. Endsley & Kiris, 1995;Endsley & Kaber, 1999;Sheridan & Verplank, 1978) exactly matched the differences seen in the rail setting. Therefore four distinct scales were established to describe automation at the four different decision making stages in the context of rail control.…”

“…Situation awareness is frequently measured in experimental studies of levels of automation (e.g. Kaber et al, 2006;Endsley & Kaber, 1999), with higher levels of situation awareness potentially improving performance during automation failures (Kaber et al, 2000). Despite the interesting results that have emerged from lab-based studies, situation awareness was not included in this study; this was primarily due to the lack of a validated tool for measurement of situation awareness in the rail signalling environment (Golightly et al, 2012) and the need to first understand which factors should be measured with regard to situation awareness in a signalling context.…”

“…The experiment therefore gathered data on real world use of automation in contrast to much of the literature in the area which tends to use artificial simulations and/or non-expert participants (e.g. Lee & Moray, 1994;Sauer, Nickel & Wastell, 2013;Röttger, Bali, & Manzey, 2009;Endsley & Kaber, 1999;Bagheri & Jamieson, 2004;Beck, Dzindolet, & Pierce, 2007;Muir & Moray, 1996;Johnson et al, 2002;Meyer, Feinshreiber, & Parmet, 2003). Other studies which did use real world systems and expert operators have typically been more exploratory (e.g.…”