Diagnosticity and multidimensional subjective workload ratings

Abstract

A new multidimensional subjective workload assessment instrument -- Workload Profile -- was introduced and evaluated against two unidimensional instruments -- Bedford and Psychophysical scaling. Subjects performed two laboratory tasks separately (single task) and simultaneously (dual task). The multidimensional procedure compared well with the unidimensional procedures in terms of sensitivity to task demands, concurrent validity with performance, and test-retest reliability. The results suggested that the subjective workload profiles would only have limited predictive value on performance. However, results of the canonical analysis demonstrated that the multidimensional ratings provided diagnostic information on the nature of task demands. Further, the diagnostic information was consistent with the a priori task characterization. This strongly supports the notion that mental workload is multidimensional and that subjects are capable of reporting the demands on separate workload dimensions. Theoretical implications on mental workload models and practical implications on the assessment approaches are discussed.

Miles away: determining the extent of secondary task interference on simulated driving

“…The idea of a general reservoir supplying separate pools of resources is becoming accepted in the literature (e.g. Matthews et al, 1996, Tsang and Velazquez, 1996, Brown, 1997. Future work could be dedicated to investigating the validity of the multiple resource model of MWL, by using matched verbal and spatial secondary tasks, in addition to exploiting different input and response modalities.…”

The Importance of Human Mental Workload in Web Design

“…In this paper we focus on subjective multidimensional measures and we use three wellestablished tools: The NASA Task Load Index (NASA-TLX) (Kantowitz, 1988); The Simplified Subjective Workload Assessment Technique (SWAT) (Luximon and Goonetilleke, 2001); The Workload Profile (WP) (Tsang and Velazquez, 1996). In the following paragraphs, we briefly describe each technique, introducing the formal models in section 3.…”

TOWARD SOCIAL SEARCH - From Explicit to Implicit Collaboration to Predict Users’ Interests

“…On the other hand, when task difficulty is negligible, systems can impose a low MWL on operators: this should be avoided as it leads to difficulties in maintaining attention and increasing reaction time [5]. Subjective measures of MWL include multi-dimensional approaches such as NASA's Task Load Index (N ASAT LX) [15], the Subjective Workload Assessment Technique [29], the Workload Profile [36] as well as uni-dimensional measures such as the Copper-Harper scale [7], the Rating Scale Mental Effort [47], the Subjective Workload Dominance Technique [39] and the Bedford scale [30]. These subjective techniques have low implementation requirements along with low intrusiveness and high subject acceptability.…”

“…For instance, the N ASAT LX has been used for evaluating user interfaces in health-care [23]. Similarly, the Workload Profile [36], the NASATLX and the Subjective Workload Assessment Technique [29] have been compared in a user study to evaluate different web interfaces [24]. Tracy and Albers adopted three different techniques for measuring mental workload applied to web-site design: N ASAT LX, the Sternberg Memory Test and a tapping test [34] [2].…”

“…• the Workload Profile (W P ) [36], based on the multiple resource theory [41], [40] A. The NASA Task Load Index…”