The majority of low income workers of developing countries are working in unorganised sectors and exposed to various stressful job environments called occupational stress that is evaluated in terms of occupational stress index (OSI). House maids perform varieties of household work and they globally constitute a significant percentage of unorganised sector workers. Ninety-four house maids of Kolkata, India, belonging to the age range of 20-60 years were recruited in this cross-sectional study to investigate the prevalence of OSI among them. The OSI parameters depicted the extent of excessive stress in this population while the OSI scores varied in different age groups. Correlation statistics revealed significant relationship of some of these OSI parameters with some of the other parameters. Such a high level of occupational stress may result in serious detrimental health hazards in this population. Urgent social attention is needed to attenuate this potentially high risk of physical and mental strains for sustaining health. It is high time to develop effective stress management strategies not only for reducing their mental and physical stress but also for enabling them to maintain healthy wellbeing.

The aim of this study is to investigate how the formation of mental models can contribute to user interface design. The differences in the formation of mental models among participants with high and low comprehension about the function of a graphical user interface (GUI)-based system was investigated. The participants were divided into two groups based on their measured comprehension regarding the GUI’s functionality. The groups could have a different level of functional model formation, which is one aspect of mental models. The verbal protocols obtained during the GUI tasks of both groups were summarized by using nine mental model elements, and the processes of mental model formation were analyzed using the Decision Making Trial and Evaluation Laboratory (DEMATEL) method. The results reveal differences among participants with different levels of mental models. Moreover, the transition probabilities between each mental model element were compared for both groups to determine differences in their processes. In particular, concept formation based on an understanding of the situation might be an important factor for enhancing the formation of mental models. Moreover, the users that could form mental models appeared to have better planning ability. These findings will be useful for the formation of ergonomic GUI design guidelines.

In the past 20 years, computers and their workplaces have increased at both offices and houses, which consequently has led to saving in time, energy and resources. This study aimed to weighting variables of musculoskeletal disorders (MSDs) among computer users through a support vector machine (SVM). This study was performed in seven steps: 1) choosing effective variables of musculoskeletal disorders on computer users; 2) evaluating effective variables on by Rapid Office Strain Assessment (ROSA); 3) calculating the final score (target) of MSDs of computer users (by ROSA method); 4) data preprocessing; 5) using SVM algorithm to weighting effective variables; 6) calculating the accuracy of SVM; and 7) data analysis. One hundred thirty-one workstations (65.5%) had a score less than 5 and 69 workstations (34.5%) had a score equal to or greater than 5. The chair variable with a normalized weighting 37%; the telephone-monitor variable with a normalized weighting 34% and finally the mouse-keyboard variable with a weighting 29% were effective variables, respectively. The ergonomic interventions and reforms considering the effect of each variable (normalized weighting of variables) should be done first for chairs; like using an ergonomic adjustable chair; then for a telephone-monitor; like setting their distance to the user etc. and at least reforming actions should be done for a mouse-keyboard; like using the ergonomic proper distance.