This study aims to investigate the orthogonality assumption, which restricts the use of Bifactor item response theory under different conditions. Method: Data of the study have been obtained in accordance with the Bifactor model. It has been produced in accordance with two different models (Model 1 and Model 2) in a simulated way. Results: As a result of the research, it was found out that the case that two factors were correlated (Model 1) and that all factors were correlated (Model 2) had the same effect on the accuracy of both person and item parameter estimations. While estimating the discrimination parameters, as the orthogonality violation increased, it was concluded that the bias increased, too. As the test length increased, the accuracy of estimations of discrimination and difficulty parameters, namely the reliability decreased. Increasing the number of items increased the accuracy of person parameters, which was the reliability.

The purpose of this study is to determine the opinions of research assistants who have been appointed to a uniform position through the various provisions on position diversity and the appointment criteria in the appointment process. This research is a case study from among the qualitative research methods. The data in the research have been collected using a semi-structured interview form developed by the researchers. The study group consists of 15 participants continuing their graduate studies working as research assistants at different universities. Data have been analyzed using descriptive and content analyses. According to the analysis results with regard to the various provisional appointments, research assistants for the 50d position are seen to have more worries than research assistants for the 33a position due to the lack of guaranteed employment, which affects their academic and social lives. Among the findings, problems such as continuous changes in position diversity, disentitlement of those appointed by the Academic Staff Training Program and not returning their rights to them are also seen to have increased research assistants' concerns regarding academia, their academic improvement, and academic future. As for research assistants' appointment criteria, adjustıng the process ıs suggested by focusing more on foreign language scores, standardizing foreign language tests that measure all aspects of language skills, having quality interviews or a quality centralized examination, and including scientific activities that have been participated in during their undergraduate years in the process. In order to make qualified scientific publications and to have publications emerge with high added value, research assistants should neither live in a fear of becoming unemployed nor live with anxiety about the future; a work environment should be provided in accordance with these.

There is a great deal of research about item response theory (IRT) conducted by simulations. Item and ability parameters are estimated with varying numbers of replications under different test conditions. However, it is not clear what the appropriate number of replications should be. The aim of the current study is to develop guidelines for the adequate number of replications in conducting Monte Carlo simulation studies involving unidimensional IRT models. For this aim, 192 simulation conditions which included four sample sizes, two test lengths, eight replication numbers, and unidimensional IRT models were generated. Accuracy and precision of item and ability parameter estimations and model fit values were evaluated by considering the number of replications. In this context, for the item and ability parameters; mean error, root mean square error, standard error of estimates, and for model fit; 2 , 2 , and Type I error rates were considered. The number of replications did not seem to influence the model fit, it was decisive in Type I error inflation and error prediction accuracy for all IRT models. It was concluded that to get more accurate results, the number of replications should be at least 625 in terms of accuracy of the Type I error rate estimation for all IRT models. Also, 156 replications and above can be recommended. Item parameter biases were examined, and the largest bias values were obtained from the 3PL model. It can be concluded that the increase in the number of parameters estimated by the model resulted in more biased estimates.

The aim of this study is to determine to which extent the measurement tool development steps that should be followed during the development of self-efficacy scales used in education and psychology are met. In line with this general purpose, the following questions tried to be answered for each study that was examined regarding the five sections, which were introduction, theoretical background, item writing, validity and reliability (for first and second implementation). In the scope of the study, document analysis was implemented. The self-efficacy development studies in the national and international literature between 1997 and 2018, which were possible to get in the electronic environment, were examined in the scope of the research. It was determined that one of the deficiencies often seen when the self-efficacy scales are examined is that the psychological structure is not defined operationally. And also the mistake that was often encountered in scale validity studies was seen to be making both explanatory and confirmatory factor analyses on the same data set. One of the most remarkable mistakes done is the confusion of scale and questionnaire. That there is a confusion regarding concepts means the scale developers do not know the difference between a scale and a questionnaire yet.

Peritraumatic distress, which is regarded as a predictor of post-traumatic stress disorder (PTSD), expresses the feeling of fear and helplessness experienced in the face of a traumatic event. It has been evaluated that the COVID-19 pandemic can lead to peritraumatic reactions and PTSD symptoms. The study aimed to adapt the "COVID-19 Peritraumatic Distress Index (CPDI)", which was developed to determine peritraumatic distress levels during the COVID-19 pandemic, to Turkish culture. The study was conducted with 248 participants. The CPDI scale items were translated into the Turkish language. Confirmatory factor analysis (CFA) was performed to determine the construct validity of the scale. And the Cronbach alpha (α) reliability coefficient was calculated for reliability. As a result of the analyses, the original structure of the scale was confirmed and construct validity was ensured. This measurement tool can be used to assess the peritraumatic distress levels of the Turkish population.