درخت حوزه‌های تخصصی

Every company should think about producing new goods, the production of alternative goods is necessary in order to stabilize the level of sales or new sales; Customers also want new products, and if the company neglects to do so, competitors will certainly do so. Therefore, the present article seeks to provide a model appropriate to the conditions of gas refining companies for product development. In this study, the qualitative research method has been used as a grand theory; Using theoretical sampling and theoretical saturation, 20 experts of gas refining companies (Parsian, South Pars, Fajr Jam) were interviewed. Based on the basic theory, the data were analyzed in three stages of coding (open, axial and selective) using MAXQDA software. In the open coding phase, the data were labeled conceptually and then those that were common to each other were named into a category; the obtained categories were 43 categories. In the central coding stage, logical relationships were found between the categories and the obtained categories were included in the open coding under more general categories; finally, in the selective coding stage, all categories were summarized in one main category. The main category of the research was named "Interfering factors in new product development". The final result of this research, according to the researcher's attention and reflection on the details of the process of each of the three refining companies, is to provide an existing common model for all three companies and also to provide a common desired model for all three companies. In the open coding phase, the data was labeled conceptually and then those that were common to each other were named into a category; The obtained categories were 43 categories. In the central coding stage, logical relationships were found between the categories and the obtained categories were included in the open coding under more general categories; Finally, in the selective coding stage, all categories were summarized in one main category. The main category of the research was named "Interfering factors in new product development". The final result of this research, according to the researcher's attention and reflection on the details of the process of each of the three refining companies studied, providing a common model for all three companies and also providing a common model for all three companies.

The generalizability aspect of Construct validity, as proposed by Messick (1989), requires that a test measures the same trait across different samples from the same population. Differential Item functioning (DIF) analysis is a key component in the fairness evaluation of educational tests. University entrance exam for the candidates who seek admission into master's English programs (MEUEE) at Iranian state universities is a very high stakes test whose fairness is a promising line of research. The current study explored gender and major DIF in the general English (GE) section of the MEUEE using multiple-indicators multiple-causes (MIMIC) structural equation modelling. The data of all the test takers (n=21,642) who took the GE section of the MEUEE in 2012 were analyzed with Mplus. To determine whether an item is flagged for DIF both practical and statistical significance were considered. The results indicated that 12 items were flagged for DIF in terms of statistical significance. However, only 5 items showed practical significance. The items flagged for DIF alert the test developers and users to potential sources of construct-irrelevant variance in the test scores which may call into question comparison of the test takers’ performance, especially when the tests are used for selection purposes.