The Impact of Uncertain Contact Location on Situation Awareness and Performance in Simulated Submarine Track Management.

OBJECTIVE: The aim of these studies was to examine the extent to which uncertainty in contact location in submarine track management affected operator situation awareness (SA), workload, and performance and whether operator SA predicted unique variance in performance. BACKGROUND: We extend prior research by manipulating uncertainty in contact location and by including a sample of expert track managers in a submarine combat system. METHOD: In Experiment 1, university students completed a track management task. In Experiment 2, expert submariners were embedded in a real submarine combat system. Uncertainty was manipulated and SA was measured using the situation present assessment method. RESULTS: Increased uncertainty led to higher student workload and moderately impaired SA and performance, and SA predicted incremental variance in performance. Uncertainty had no effect on expert SA or the accuracy of the tactical picture compiled. On average, experts took 20 s to accept SA queries (compared with 2.18 s for students). The time taken for experts to accept SA queries, but not their subsequent response to SA queries, was positively associated with their tactical picture accuracy. CONCLUSION: Uncertainty can negatively impact SA, workload, and performance. Some key findings from the laboratory were replicated using experts, but the fact that experts took on average 20 s to accept SA queries presents a challenge for using SPAM in submarine control rooms. APPLICATION: Contact location is uncertain due to the use of passive sonar and hostile deception. It is essential to measure track manager SA in order to inform work design and training.

Situation awareness measures for simulated submarine track management.

OBJECTIVE: The aim of this study was to examine whether the Situation Present Assessment Method (SPAM) and the Situation Awareness Global Assessment Technique (SAGAT) predict incremental variance in performance on a simulated submarine track management task and to measure the potential disruptive effect of these situation awareness (SA) measures. BACKGROUND: Submarine track managers use various displays to localize and track contacts detected by own-ship sensors. The measurement of SA is crucial for designing effective submarine display interfaces and training programs. METHOD: Participants monitored a tactical display and sonar bearing-history display to track the cumulative behaviors of contacts in relationship to own-ship position and landmarks. SPAM (or SAGAT) and the Air Traffic Workload Input Technique (ATWIT) were administered during each scenario, and the NASA Task Load Index (NASA-TLX) and Situation Awareness Rating Technique were administered postscenario. RESULTS: SPAM and SAGAT predicted variance in performance after controlling for subjective measures of SA and workload, and SA for past information was a stronger predictor than SA for current/future information. The NASA-TLX predicted performance on some tasks. Only SAGAT predicted variance in performance on all three tasks but marginally increased subjective workload. CONCLUSION: SPAM, SAGAT, and the NASA-TLX can predict unique variance in submarine track management performance. SAGAT marginally increased subjective workload, but this increase did not lead to any performance decrement. APPLICATION: Defense researchers have identified SPAM as an alternative to SAGAT because it would not require field exercises involving submarines to be paused. SPAM was not disruptive, but it is potentially problematic that SPAM did not predict variance in all three performance tasks.

Turning simple span into complex span: Time for decay or interference from distractors?

We investigated the effects of the duration and type of to-be-articulated distractors during encoding of a verbal list into short-term memory (STM). Distractors and to-be-remembered items alternated during list presentation, as in the complex-span task that underlies much of working-memory research. According to an interference model of STM, known as serial order in a box (SOB; Farrell & Lewandowsky, 2002), additional repeated articulations of the same word between list items should cause minimal further disruption of encoding into STM even though the retention interval for early list items is increased. SOB also predicts that the articulation of several different distractor items should lead to much enhanced disruption if the distractor interval is increased. Those predictions were qualitatively confirmed in 4 experiments that found that it is the type of distractors, not their total duration, that determines the success of encoding a list into STM. The results pose a challenge to temporal models of complex-span performance, such as the time-based resource sharing model (Barrouillet, Bernardin, & Camos, 2004). The results add to a growing body of evidence that memory for the short term is not exclusively governed by purely temporal processes.