Comfort is a sensation and state of being that many people seek when they are working in the office, driving in a car, flying on an airplane, or laying in a hospital bed. The literature identifies many definitions and interpretations for comfort and discomfort, and many different ways that researchers have tried to measure comfort and discomfort. de Looze proposed a model to explain the relationship between comfort and discomfort using three key components: (a) the human, (b) the product, and (c) the environment. This dissertation added a measurement component to the model. In a repeated measures design, subjects (n=35) sat in three different office chairs for 60 minutes each on two different dates. Researchers collected subjective survey data and objective electronic data related to perceived sitting comfort and discomfort while participants completed office computer tasks. Data were analyzed to predict and quantify office worker seated comfort and discomfort using linear modeling and neural network modeling. Correlation values from the linear regression model developed in this experiment were R2 < 0.70, while the single hidden-layer neural network model predicted the comfort/discomfort responses with a higher correlation (R2=0.997). The 35 subjects in the study perceived measurable comfort differences between the three chairs tested. Subjective questions that treated comfort and discomfort in a non-linear relationship discriminated chair differences better than questions using a linear relationship. There was no significant difference between male and female comfort/discomfort responses. Comfort ratings decreased over time, while discomfort increased over time; at least 45-minute comfort testing is needed to understand subjects' comfort/discomfort in a particular office chair. Five common factors that were important to the model included: (a) fit of the product to the person, (b) the features of the product itself, (c) the time spent with the product, (d) the subjective questions, and (e) the objective pressure measurements.

Made available in DSpace on 2015-05-08T14:53:36Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1371187 bytes, checksum: ae8fa3bf2ba2aacb9df465b6d4792141 (MD5) Previous issue date: 2013-10-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Workload is the functional relationship between the demands of work and the worker s biological and psychological capabilities. The NASA-TLX is a method that provides the measurement of the workload through the worker s perception. This is because such method uses subjective measures, that is, through a questionnaire addressed to the worker answers referring to the functional aspects are obtained. This measurement of the workload can be used to assist in the reorganization of situations and in early diagnosis of diseases, allowing planning hierarchically preventive and treatment actions. This research is characterized as descriptive in terms of its goals and its aim was to evaluate commercial servers workload. Ergonomic aspects which could contribute to the final result of the workload were also evaluated. In order to it, a case of study was conducted in small agencies of the Brazilian Company of Post and Telegraph in the Federal District, during the first semester of the current year. According to the analyzed variables, the criterion which most contributed to the final result of workload was the mental demand, and the one that less influenced it was the frustration level. With its results, the aim of this research is to subsidize improvements in the commercial servers work processes, contributing to a better quality of work. / Carga de trabalho é a relação funcional entre as exigências do trabalho e as capacidades biológicas e psicológicas do trabalhador. O NASA-TLX é um método que permite aferir a carga de trabalho sob a percepção do trabalhador. Isto porque este método utiliza medidas subjetivas, ou seja, por meio de um questionário direcionado ao trabalhador são obtidas respostas referentes aos aspectos funcionais. Esta mensuração da carga de trabalho pode ser utilizada para auxiliar na reorganização de situações e no diagnóstico precoce de agravos à saúde, permitindo planejar de forma hierárquica ações preventivas ou de tratamento. A presente pesquisa com relação aos objetivos caracteriza-se como descritiva e teve como objetivo avaliar a carga de trabalho de atendentes comerciais. Foram avaliados também aspectos ergonômicos que poderiam contribuir no resultado final da carga de trabalho. Para tanto, foi realizado um estudo de caso nas Agências comerciais de pequeno porte da Empresa Brasileira de Correios e Telégrafos do Distrito Federal, no primeiro semestre do presente ano. Conforme as variáveis analisadas, o critério que mais contribui no resultado final da carga de trabalho foi a demanda mental e a que menos influenciou foi o nível de frustração. Pretende-se com os resultados desta pesquisa subsidiar melhorias nos processos de trabalho dos Atendentes comerciais, contribuindo para uma melhoria da qualidade do trabalho.

The purpose of this study was to investigate the effect of an instruction designed by the Cognitive Load Theory (CLT) principles on 7th grade students