Experimental testing and evaluation of orthogonal waveforms for MIMO radar with an emphasis on modified Golay codes

Alex Burwell


Vigilance research often includes measuring the observer's subjective workload. The most commonly used NASA Task Load Index (NASA-TLX), requires several minutes to administer; typically at the end of an experiment. A more recently developed workload measure, the Simplified Subjective Workload Assessment Technique (S-SWAT), may provide researchers with further insights into perceived workload throughout a vigilance task. To date, no studies have measured workload using the S-SWAT in a vigilance experiment, specifically in the area of workload transitions. To date, only one study has examined perceived workload during a vigilance transition task; this study used the NASA-TLX. The goal of the present research was to explore the usefulness of the S-SWAT, determine how S-SWAT ratings compare to NASA-TLX ratings, and identify any effects on performance that the S-SWAT might create. Results showed that the S-SWAT had no impact on performance; this supports the potential of the S-SWAT as an instrument for better understanding the impact of task changes on perceived workload during a vigil. The S-SWAT, which is administered multiple times over the course of a vigil, provides more detail and helps identify trends of perceived workload, over time, compared to a single collection with the NASA-TLX. However, it is important to note that workload ratings on the NASA-TLX were higher when the S-SWAT was used in higher workload condition as compared to the ratings from when it was used in a low workload condition or when a control group reported workload only at the end of the vigil. While further research is needed to better understand the impact that the S-SWAT has on perceived workload, this study provides some evidence that the S-SWAT may be a useful measure throughout a vigilance task for gaining more insight into the workload experienced by observers.