Comparative Analysis of Subjective Mental Load Measurement Methods Between NASA TLX and DASS-42

Mental workload remains a critical concern in industrial settings, as ineffective stress regulation can lead to decreased productivity and potentially increase the likelihood of workplace accidents. This study aims to compare and contrast two subjective assessment tools for evaluating workers’ mental load, the NASA Task Load Index (NASA-TLX) and the Depression Anxiety Stress Scales (DASS-42). In this experiment, 30 participants were assigned a time-constrained CAD design task. The NASA-TLX evaluates workload across six dimensions: mental demand, physical demand, temporal demand, perceived performance, effort, and frustration level. Analysis of the NASA-TLX responses revealed that participants numbered 18, 27, and 29 exhibited exceptionally high stress levels. Conversely, results from the DASS-42 instrument indicated that only participants 18 and 27 experienced high levels of psychological stress, whereas participant 29 showed a moderate stress response. These findings suggest that DASS-42 captures a broader spectrum of mental strain, including stressors that may originate from beyond the immediate work environment.