Evaluation of decision-tree rating scales for mental workload estimation

Abstract

Recent studies suggest that a decision-tree rating scale called the Modified Cooper-Harper (MCH) rating scale is a globally sensitive indicator of change in mental loading (Wienville and Casali 1983a). The present study was directed at developing refinements in the scale and at obtaining additional background information. The MCH scale and five design variations of the scale were studied in two independent aircraft-simulator experiments. Aspects studied were the decisiontree structure, the number of categories, the d&ision.:sequence and the effects of computer implementation. Results using the rating scales indicate that the MCH scale and its computerized version are generally more consistent than the others. Attendant questionnaire results indicate that pilots base their ratings on the same factors that researchers believe are the important elements of the multidimensional construct of workload.

Comparison of NASA-TLX scale, modified Cooper–Harper scale and mean inter-beat interval as measures of pilot mental workload during simulated flight tasks

“…The objective of this study was to investigate if there are differences between NASA-TLX, MCH and IBI when the fighter pilots' MWL was measured during the simulated flying mission. NASA-TLX, MCH and IBI have all been successfully and widely used to (indirectly) measure MWL (Mansikka et al 2016b;Wang et al 2016;Zhang et al 2009;Di Nocera, Camilli, Terenzi 2007;Dennis and Harris 1998;van Westrenen 1996;Moroney et al 1992;Hill et al 1992;Battiste and Bortolussi 1988;Skipper, Rieger, and Wierwille, 1986;Casali and Wierwille 1984;Casali and Wierwille 1983). However, due to the complexity and uniqueness of many man-machine systems (Carayon et al 2015;Dekker 2012;Carayon et al 2006;Verwey and Veltman 1996) and human information processing (Wickens 2008), it was necessary to conduct a study which specifically investigated their association in a modern FTD, using a realistic flying mission and operational fighter pilots.…”

“…The nonintrusiveness, ease of use and low-cost implementation of the subjective MWL measures are some of the features that motivate their usage (see e.g., Fallahi et al, [2016]; Gabriel, Ramallo, and Cervantes [2016], Akyeampong [2014]; Prichard., Bizo, and Stratford., [2011]; DiDomenico and Nussbaum [2008]; Newell and Mansfield [2008]; Sato et al, [1999]) For subjective MWL measuring, there are many different methods to choose from. These include, but are not limited to, methods such as NASA Task Load index (NASA-TLX) (Hart and Staveland 1988) and Modified Cooper-Harper scale (MCH) (Wierwille and Casali 1983), which are both widely used in an aviation domain (Zhang et al 2009;Di Nocera, Camilli, and Terenzi 2007;Dennis and Harris 1998;van Westrenen 1996;Moroney et al 1992;Hill et al 1992;Battiste and Bortolussi 1988;Skipper, Rieger, and Wierwille, 1986;Casali and Wierwille 1984;Casali and Wierwille 1983). Some techniques, like NASA-TLX, are multidimensional measuring scales, which use several different dimensions to assess MWL.…”