Item Difficulty and Item Discrimination Coefficient for School and College Ability Tests (SCAT) Advanced Form in Classical Test Theory (CTT) and Item Response Theory (IRT) and the Correlation among Them Mohammad moqasqas Haifa T. Albokai Assistant Professor of Measurement and Evaluation Associate Professor of Measurement and Evaluation College of Education, Taibah University The aim of this study was to study the item difficulty and item discrimination of the SCAT (advance form) with CTT, and IRT, and to study the correlation among them. To do this, the researchers used the data of their previous study, which conducted in (2011). It consisted of (3943) subject. Then, they used two-statistical programs (TAP, Bilog-MG-3) to obtain the item difficulty and item discrimination coefficient in CTT and IRT. The results revealed a good item difficulty and item discrimination coefficient. Additionally, it showed a significant correlation between CTT and IRT in item difficulty and item discrimination. The researchers recommended of using any of these two theories to obtain the item difficulty and item discrimination for the tests and to do extended studies for the SCAT.
Mixed-effects conditional logistic regression is evidently more effective in the study of qualitative differences in longitudinal pollution data as well as their implications on heterogeneous subgroups. This study seeks that conditional logistic regression is a robust evaluation method for environmental studies, thru the analysis of environment pollution as a function of oil production and environmental factors. Consequently, it has been established theoretically that the primary objective of model selection in this research is to identify the candidate model that is optimal for the conditional design. The candidate model should achieve generalizability, goodness-of-fit, parsimony and establish equilibrium between bias and variab
... Show MoreThe present work aims to study the removal of dyes from wastewater by reverse osmosis process. Two dyes were used direct blue 6, and direct yellow. Experiments were performed with feed concentration (75 – 450 ppm), operation temperature (30 – 50 oC) and time (0.2 – 2.0 hr). The membrane used is thin film composite membrane (TFC). It was found that modal permeate concentration decreases with increasing feed concentration and time operating, while permeate concentration increases with increasing feed temperature. Also it was found that product rate increase with increasing temperature, but it decrease with increasing feed concentration and time. The concentration of reject solution showed an increase with increasing feed concentratio
... Show MoreIn order to promote sustainable steel-concrete composite structures, special shear connectors that can facilitate deconstruction are needed. A lockbolt demountable shear connector (LB-DSC), including a grout-filled steel tube embedded in the concrete slab and fastened to a geometrically compatible partial-thread bolt, which is bolted on the steel section's top flange of a composite beam, was proposed. The main drawback of previous similar demountable bolts is the sudden slip of the bolt inside its hole. This bolt has a locked conical seat lug that is secured inside a predrilled compatible counter-sunk hole in the steel section's flange to provide a non-slip bolt-flange connection. Deconstruction is achieved by demounting the tube from the t
... Show MoreDue to severe scouring, many bridges failed worldwide. Therefore, the safety of the existing bridge (after contrition) mainly depends on the continuous monitoring of local scour at the substructure. However, the bridge's safety before construction mainly depends on the consideration of local scour estimation at the bridge substructure. Estimating the local scour at the bridge piers is usually done using the available formulae. Almost all the formulae used in estimating local scour at the bridge piers were derived from laboratory data. It is essential to test the performance of proposed local scour formulae using field data. In this study, the performance of selected bridge scours estimation formulae was validated and sta
... Show MoreThe necessary optimality conditions with Lagrange multipliers are studied and derived for a new class that includes the system of Caputo–Katugampola fractional derivatives to the optimal control problems with considering the end time free. The formula for the integral by parts has been proven for the left Caputo–Katugampola fractional derivative that contributes to the finding and deriving the necessary optimality conditions. Also, three special cases are obtained, including the study of the necessary optimality conditions when both the final time and the final state are fixed. According to convexity assumptions prove that necessary optimality conditions are sufficient optimality conditions.
... Show MoreIn order to advance the education process and raise the educational level of the players, it became necessary to introduce new educational aids, programmed education in the education process, through which the basic skills to be learned are explained and clarified, and immediate feedback is provided that would enhance the information of the learner, and Reaching the goal to be achieved, taking into account the individual differences between the players, and thus it is possible to move away from the educational methods used in learning skills, which requires great effort and time, in addition to that the open playground may not perform the skill accurately and the player looks from one side, while when using the computer you look from severa
... Show MoreThe analysis of time series considers one of the mathematical and statistical methods in explanation of the nature phenomena and its manner in a specific time period.
Because the studying of time series can get by building, analysis the models and then forecasting gives the priority for the practicing in different fields, therefore the identification and selection of the model is of great importance in spite of its difficulties.
The selection of a standard methods has the ability for estimation the errors in the estimated the parameters for the model, and there will be a balance between the suitability and the simplicity of the model.
In the analysis of d
... Show MoreThe relationship between the vision of the scenario and the director is represented in the second search for new mechanisms and possibilities that possess the direct effect and synonyms of the vision of the scenario, so he works on investing them in achieving his ideas and visions with more effectiveness and flexibility to achieve creative potentials, without resorting to the installations and expressive structures themselves that have exhausted their meaning, and lost their luster due to Its prevalence and familiarity on the one hand, and its activation on the other hand to achieve modernity at the level of aromas, after the director takes a method or approach that has privacy and exclusivity, and based on the foregoing, getting
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