Evidence of validity and precision of the instruments used to measure mental workload: an integrative review of the literature

Mental workload represents the value attributed to the mental effort required to perform tasks. The aim of this study was to identify evidence of validity and accuracy of instruments used to measure mental workload in the last 10 years, through a literature review. Searches were conducted in Scopus, Web Of Science, PsycNet, PubMed and the VHL portal (2012-2021), in English, Spanish and Portuguese. A total of 145 articles were included, and 16 instruments for measuring the CMT were located. The results demonstrate the use of information about the psychometric properties of instruments that depart from statistical concepts and procedures that are not always consistent with the verification of the internal structure of the construct. The validity of the instruments' internal structure was verified in only four studies, with satisfactory reliability indices, but still with the use of unsatisfactory concepts and methodologies for treatment and analysis. There are, therefore, methodological, technical and conceptual challenges in the processes of measuring mental workload.