NASA Task Load Index (NASA-TLX)

The NASA Task Load Index (NASA-TLX) is a multidimensional subjective workload assessment tool developed by Sandra Hart and Lowell Staveland at NASA's Ames Research Center in 1988. It measures six dimensions of cognitive and physical task load to quantify operator workload across diverse task domains, from aviation and process control to human-computer interaction. The TLX has become the gold standard for workload measurement in human factors research and applied settings.