Showing 12 results for Reliability
Javad Faradmal, Javad Keshvari Kamran,
Volume 2, Issue 3 (12-2014)
Abstract
Introduction: Index of usability
evaluates performance, user satisfaction and increased productivity in a
product. Principles of usability are effectiveness, efficiency, safety, utility,
learnability, Memorability. This Study Aims to Develop a Tool to Estimate and
Evaluate the Usability of Web Applications in the field of Automation Research
has been determined.
Material and Methods: After extracting,
an initial questionnaire to assess the usability of the standard resource for
indices of validity, internal consistency and reproducibility, respectively
technique for determining the content validity, test-retest method and
cronbach's alpha coefficient were used. The most important steps were as follow:
(1) determine the scope and dimensions of the questions (2) preparing draft questionnaire (3) appoint the members of the expert panel (4) methods, how
data analysis (5) determine the acceptance criteria
of the questions (6) determine the content validity index (7) determine reliability
of the questionnaire (8) determine reproducibility of the questionnaire.
Results: A 50-Item
questionnaire was designed as the ultimate tool. The content validity index
value of 0.763 was obtained ultimately for the questionnaire. Analysis of the
questionnaire responses revealed that the lower backend errors related to the
reliability coefficient alpha value was equal to 0.742. Finally, the degree of
reproducibility of the questionnaire, using test-retest method, was equal to
value of 0.993 (p <0.001).
Conclusion: After the
final questionnaire design, with good reliability and validity, it is
noticeable that the designed tool is applicable on relevant softwares and may
improve the quality and efficiency of the software and user interface.
Fozieh Javadpour, Sareh Keshavarzi, Alireza Choobineh, Mandana Aghabaigi,
Volume 3, Issue 1 (6-2015)
Abstract
Introduction: Perceived work-related
fatigue is an important issue since it may adversely impact workers’
performance. Additionally, workers’ fatigue is known as a main cause of
occupational accidents in workplaces. Considering the consequences of perceived
work-related fatigue, assessing fatigue at workplace is critical to
work-related fatigue risk management. Therefore, this study assessed the
validity and reliability of the Persian version of the Swedish Occupational
Fatigue Inventory (SOFI-20) among Iranian employees.
Materials and Methods: In this cross-sectional
study, 501 employees of two petrochemical companies were selected by simple
sampling method. The Persian version of SOFI-20 was developed using forward and
backward translation processes and used to collect the required data. The
validity and reliability of the translated inventory were examined by
confirmatory factor analysis (CFA) and Cronbach’s alpha coefficient,
respectively.
Results: Assuming
that some items of the Persian version of the SOFI-20 were correlated, the
confirmatory factor analysis was repeated to achieve better fitness. The results of CFA revealed an acceptable fit for the
Persian version of SOFI-20. The total Cronbach’s Alpha coefficient for the
SOFI-20 was 0.95. Cronbach’s alpha coefficients for different dimensions of the
SOFI-20 were found to range from 0.690 to 0.887.
Conclusion: The validity and
reliability of the Persian version of the SOFI-20 was acceptable for assessing
the dimensions of work-related fatigue among Iranian employees.
Hamidreza Mokhtarinia, Asrin Shafiee, Marzieh Pashmdarfard,
Volume 3, Issue 3 (12-2015)
Abstract
Introduction: Musculoskeletal disorders are among the top 10 injuries accounting for absence from work. The Extended Nordic Musculoskeletal Questionnaire (NMQ-E) is one of the many tools used to examine these disorders. The present study was conducted to translate and localize the NMQ-E and to evaluate the face validity and test-retest reliability of its Persian version.
Materials and Methods: The present non-empirical methodological study used the International Quality Of Life Assessment (IQOLA) approach to translate the NMQ-E into Persian. The face validity of the Persian version was examined in a sample of 15 patients with musculoskeletal disorders (MSDs) and its absolute and relative test-retest reliability were examined in a sample of 48 patients using the Standard Error of Measurement (SEM) and the Intra-class Correlation Coefficient (ICC). The Kappa coefficient was also used to measure the inter-rater agreement for nominal variables.
Results: The translation and localization of the NMQ-E was deemed easy and acceptable. All the items of the questionnaire had an acceptable face validity. The Intra-class Correlation Coefficient and the Standard Error of Measurement of the Persian version of the NMQ-E were deemed acceptable (SEM=0.56-1.76 and ICC>0.7) and the Kappa coefficient was calculated as 0.78-1.00.
Conclusion: The Persian version of the Extended Nordic Musculoskeletal Questionnaire showed an acceptable validity and test-retest reliability for assessing musculoskeletal disorders in Iranian patients.
Mohsen Shojaatian, Heydar Sadeghi,
Volume 4, Issue 2 (10-2016)
Abstract
Introduction: According to the effectiveness and low cost of prevention, ergonomic assessment methods as a means to predict the potential occurrence of injury are being used. The aim of the present research was the assessment of validity and reliability of researcher-made ergonomic assessment test for freestyle wrestling skills.
Methods: In this research, according to the jobs ergonomic evaluation tests and wrestling pathology research, an ergonomic evaluation test for wrestling skills (WSEAtest) was designed. Content and face validity were proved by using the opinions of sports biomechanics and pathology experts, as well as physicians, physiotherapists, trainers and wrestlers of Freestyle national team. Furthermore, the test was performed on three skills in two different days by five examiners, using Kinovea software 0.8.15; also, intra- and inter-tester reliability were calculated. After the reliability and validity approval, WSEAtest was performed on video records of four selected skills of Iranian freestyle wrestlers in London 2012 Olympic games.
Results: The injury exposure in various parts of body, traumatic factors related to collisions and loads, and athlete and environment conditions were consistent with wrestling pathological research and confirmed the validity of the test results.
Conclusions: WSEAtest has acceptable validity and reliability; trainers, specialists, and sports therapists can use this test to assess traumatic factors and identify priorities for training and corrective exercises in different wrestling levels, and in various ages.
Elham Pakdel, Manochehr Omidvari,
Volume 5, Issue 1 (6-2017)
Abstract
Introduction: One of the most important issues in industries is accident. Various factors affect these events, one of which is individual features. This study aimed at investigating the role of human resource personality on human reliability in accident outbreaks using DISC behavioral approach modal in automotive industry.
Methods: This was a descriptive-analytical research. The relationship of person vulnerability with human personality with fallibility was investigated. In order to determine human personality disk standard model was used and to estimate the degree of human fallibility heart techniques were used. Then, the relationships of natural personality, human reconcilable dimensions, human reliability and fallibility were found. Also, the relationship of accident repetition with personality and human fallibility was determined. This research was conducted among 98 personnel of one of the biggest production units during 2013 to 2015.
Results: The results indicated that there was a high correlation in human personality and fallibility dimension with accidents outbreak. There was a significant relationship between persons with influential personality, inherent stability, adapted stability, adapted dutiful, and accident outbreak repetition.
Conclusions: According to the results, the personality of individuals with high sensitivity in their job and less adaptation to changes made in work environment, has a higher possibility of accidents outbreaks. Perhaps, this issue is created because of the inconsistency between the management system that is ruling the industry of developing countries and personality features of those people.
Elham Ahmadi Kivanani, Mostafa Pouyakian, Abbass Alipour,
Volume 6, Issue 4 (3-2019)
Abstract
Background and Objectives: Accurate measurement of the employees’ satisfaction with their office chairs can provide valid feedback on the chair design quality for the manufacturers and researchers. This study aims to design a valid and psychometrically evaluated questionnaire for measuring satisfaction with office chairs.
Methods: Through studying the two main documents about chair ergonomics including Iranian office chair standard No. 11388-1 and a valid Persian questionnaire on satisfaction with educational chairs (Mirmohammadi et al.), the initial 39-item office chair satisfaction questionnaire has been developed. Then face and content validity of the questionnaire have been checked out using qualitative and quantitative approach. Quantitative face validity was analyzed using impact score method. Content Validity Index (CVI) and Content Validity Ratio (CVR) have been used for quantitative content validity analysis. In order to analyze the questionnaire’s reliability, two methods including the internal consistency and constancy have been applied. To measure the internal consistency, α-Cronbach (alpha coefficient) and to evaluate constancy (test-retest) have been employed. Also, the receiver operating characteristic (ROC) curve was utilized for specifying its sensitivity, specificity, and cut-off point. The data was analyzed by SPSS 21 and Stata V.14
Results: Mean (CVR) and (CVI) of final questionnaire have been calculated as 0.93 and 0.95, respectively. Questionnaire’s α-Cronbach coefficient has been gained 0.8. Kappa coefficient (for inter-rater agreement) has showed high score (0.91) in the test-retest results, indicating high correlation and good constancy of the questionnaire. In the ROC, the cut-off point was reported as 75.5 with the sensitivity and specificity of 86.2 and 100, respectively, and area under the ROC curve at this cut-off point was 0.96.
Conclusion: The final 34-item questionnaire has exhibited acceptable reliability and validity for measuring satisfaction level of office chairs.
Nooshin Atashfeshan, Prof Mohammad Saidi-Mehrabad, Hamideh Razavi,
Volume 9, Issue 3 (12-2021)
Abstract
Background and Objectives: Despite contribution to catastrophic accidents, human errors have been generally ignored in the design of human-machine (HM) systems and the determination of the level of automation (LOA). This paper aims to develop a method to estimate the level of automation in the early stage of the design phase considering both human and machine performance.
Methods: A quantitative method is used to evaluate the performance of the whole human-machine system by the human-in-the-loop fault tree analysis while a qualitative and cross-sectional method is used to estimate human errors using the CREAM technique. The data are collected from real cases that happened in the control room of the Ferdowsi power plant.
Results: Full automatic option with an average error of 0.013 had the lowest error rate, i.e. 1/8 of the error rate of the manual design. In addition, the CREAM analysis showed that the control room operators were not satisfied with the availability of procedures and Man-Machine Interface and operational support in general. Thus, on average, the reliability of the manual design is less than the reliability of the automatic setting.
Conclusion: High machine reliability has led to the fact that the fully automatic design would be one of the best design choices for human-machine systems. However, based on the previous studies, high automation may have some human-out-of-the-loop shortcomings. Thus, this study proposed solutions to overcome these disadvantages based on the importance of the control parameters or the essence of human involvement in some decision-making and execution tasks.
Mostafa Rahmiani Iranshahi, Masoud Shafiee Motlagh, Elahe Dortaj, Maryam Farhadian,
Volume 9, Issue 4 (3-2022)
Abstract
Background and Objectives: Visual comfort is an important and influential factor on safety, mental health, sleep quality, and musculoskeletal disorders of employees in the workplace. This study aimed to design and develop a questionnaire to assess the visual comfort of employees in the workplace.
Methods: The study was performed on 101 participants (88 men and13 women) in the food industry. First, the available lighting questionnaires in the field of lighting were reviewed, and a question bank was set up. Twenty questions were considered in two sections of natural and artificial lighting (10 questions in each section) based on the opinion of 10 experts in this field. The validity of the questionnaire was assessed using the content validity index (CVI) based on the comments of experts. To validate the questionnaire in the workplace, The lighting of employees' workstations was evaluated according to the Illuminating Engineering Society of North America (IESNA) standards and compared with the results of the questionnaire.
Results: The Cronbach's alpha of natural and artificial lighting visual comfort questionnaire was 0.858 and 0.922, respectively. The total CVI of the questionnaire was 1. There was a significant positive relationship between the score of the visual comfort questionnaire and the workstations' illumination (P = 0.001). More than 97% of employees who had workstations with the desired lighting reported excellent levels of visual comfort.
Conclusion: The visual comfort questionnaire had good and acceptable reliability and validity. This tool is recommended for the use of visual comfort asessments of employees in work environments given the fewer number of and simplicity of sentences.
Azam Maleki-Ghahfarokhi, Iman Dianat, Mohammad Asghari Jafarabadi, Mohamad Parnianpour, Mahmood-Reza Azghani, Maryam Khosravifar, Sina Samadi,
Volume 10, Issue 1 (7-2022)
Abstract
Objectives: The comfort questionnaire for hand tools (CQH) is a subjective measure for exploring the starting points for improving hand tool design. This study aimed to investigate the psychometric properties of the Farsi version of the CQH.
Methods: In this cross-sectional study, which was conducted among 163 university students, the 17-question CQH was translated into Farsi with a translation back-translation procedure. Content validity was assessed by a panel of 10 experts. Exploratory Factor Analysis (EFA) was applied for determining construct validity. Cronbach’s alpha and Intraclass Correlation Coefficient (ICC) were used for assessing internal consistency and test-retest reliability, respectively. Ceiling and floor effects were also estimated for evaluating the feasibility of the measure.
Results: The CQH showed good content validity. Content validity index (CVI) ranged from 0.80 to 1.00 and Content Validity Ratio (CVR) ranged 0.62-1.00. EFA led to extraction of two factors from the data. The first one was mostly related to functionality and physical interaction and the second one, was generally about adverse body effects. The Cronbach’s alpha was 0.74 and test-retest reliability was 0.74 (95% CI = 0.58 to 0.86) which both were satisfactory. There were no (0%) ceiling and floor effects.
Conclusion: The Farsi version of CQH is an acceptable and useful instrument for evaluating hand tools comfort.
Ali Salmaninejaad, Maryam Hasani, Sahar Rezaian,
Volume 11, Issue 2 (9-2023)
Abstract
Objectives: Psychological load, such as workload, not only disrupts work performance but can also directly affect employee safety leadin to accidents. However, despite this issue, not much effort has been made to develop an assessment tool to measure the psychological burden related to the occupational safety and health of employees. Therefore, the present study was designed to validate the psychological burden scale of workers by Kim et al. (2018) from the perspective of occupational health and safety.
Methods: The statistical population of the research consisted of all the workers employed in the Eastern Alborz Company of Shahroud city, and 349 workers participated in the research using a simple random sampling method. In the present study, the mental load scale by Kim et al. (2018), the Copenhagen psychosocial scale (COPSOQ), and the occupational stress scale (HSE) were used. The data were analyzed using Pearson's correlation coefficient tests and confirmatory factor analysis using SPSS version 22 statistical software and Lisrel version 8.5.
Results: The results showed that all the components of workers' psychological burden including the overall score and the psychosocial scale and occupational stress scale have a positive and significant relationship. The results of the confirmatory factor analysis also indicated a good fit of the model in determining the factors in the initial form as proposed by Kim et al. (2018). To determine the reliability of the scale, the value of Pearson's correlation coefficient was obtained at 0.82 in the test and retest phases. Additionally, the results of this study showed that 26.1 percent of workers experienced low psychological burden, 49.6 percent experienced moderate psychological burden, and 24.4 percent experienced severe psychological burden.
Conclusion: Based on the results of the current research, the workers' mental burden scale (Kim et al., 2018) is a valid and reliable tool that can be used to evaluate the psychological burden of workers in research and intervention studies.
Zahra Rafat, Hamidreza Mokhtarinia, Mohsen Vahedi,
Volume 11, Issue 4 (1-2024)
Abstract
Objectives: Changes in mental workload are related to performance and level of fatigue, stress, human error, and job dissatisfaction. Questionnaires are simple, accessible, and valid tools for the assessment of mental workload. Therefore, the present study aimed at translation, cultural adaptation, and evaluation of psychometric properties of the Carmen-Q mental workload questionnaire.
Methods: This study was conducted on 296 subjects (100 women and 196 men) with a mean age of 38.59±7.61 years, working in industrial and administrative sectors in several centers in Saveh. The process of translation and cultural adaptation was carried out in accordance with relevant guidelines and included the stages of forward and backward translation, synthesizing and preparing a final version, piloting, and then final approval of the Persian version. Psychometric properties, including face validity (simplicity and readability), content validity (through content validity index), convergent validity (through correlation with NASA-TLX questionnaire), and internal consistency (using Cronbach's alpha coefficient) were assessed.
Results: The translation, cultural adaptation, and face validity assessment were carried out according to related guidelines, and the text underwent some minor changes. The Content Validity Index values for each of the items and its total (0.914) were acceptable. Cronbach's alpha value was acceptable for all items (0.91) and each subscale (above 0.8). Pearson's correlation coefficient displayed a moderate to good relationship between Carmen-Q and NASA task load index.
Conclusion: The Persian version of the Carmen-Q questionnaire is a valid and reliable tool for evaluating mental workload in Iranian society.
Seyed Ghafar Hoseini, Ebrahim Zarinkalam, Reza Heidary, Majid Jalili,
Volume 11, Issue 4 (1-2024)
Abstract
Objectives: The maximum aerobic capacity (VO2max) is the most important indicator of physical fitness, which is closely related to the general health of the body. Considering the problems of laboratory measurement of VO2max, estimating VO2max by non-exercise equations will be one of the alternative solutions. This study aims to evaluate the validity of the native non-exercise equation in estimating VO2max of healthy adolescent boys.
Methods: The variables of age, height, weight, and body mass index were measured in 248 healthy boys aged 15 to 18. The subjects' VO2max was measured and predicted by exercise test and non-exercise native equation respectively. To evaluate the validity of the native non-exercise equation, Pearson's correlation, paired t-test, and Bland-Altman's agreement were used.
Results: There is a significant correlation between measured and predicted VO2max (R = 0.76, p<0.05). Also, no significant difference was observed between predicted and measured VO2max (43.10 ml/kg/min and 43.38 ml/kg/min respectively) (mean difference=0.28 ml/kg/min, P>0.05). Also, the Bland-Altman graphic diagram indicated agreement between the methods of measuring and estimating VO2max.
Conclusion: In the present study, the native non-sports equation had a high validity in estimating VO2max of adolescent boys. It seems that the use of non-sports VO2max equations can be used as a simple, safe, and low-cost tool to evaluate the maximum aerobic capacity of students at a wide level.
