Characteristics of Item Parameter Estimation for the Multidimensional Item Response Theory (MIRT)

서동기,김좌근,김경태 한국심리학회 2015 한국심리학회지 일반 Vol.34 No.2

This study analyzes the three different estimation algorithms for recovering item parameters for the compensatory multidimensional IRT (MIRT) models. In particular, two- and four-dimensional models were investigated with different degrees of correlation between latent traits. The standards such as bias, standard error, and root mean square error were used to evaluate the recovery of item parameters for each program. The results indicated that in most conditions, Metropolis-Hasting Robbins-Monro (MH-RM) outperformed full information item factor analysis (FIIFA) and bivariate information item factor analysis (BIIFA) for a-parameters except for the independent and very low inter-trait correlation conditions where BIIFA outperformed the other algorithms. However, the MH-RM algorithm consistently produced the highest empirical standard errors compared to the other two methods for all conditions. FIIFA performed at a higher standard than BIIFA for a-parameters with moderately correlated latent traits. BIIFA is more suitable for a-parameters, especially when the levels of latent traits' independence or correlation are very low, and it is more suitable for d-parameters regardless of inter-trait correlations in the four-dimensional models. Overall, three estimation methods provided more accurate a- and d-parameter as the number of examinees increased, and less accurate a-parameter occurred as the inter-trait correlation increased. The inter-trait correlation condition did not have a dramatic impact on the recovery of d-parameter across all three algorithms.

단축형 심리검사 개발의 측정학적 방법과 타당화: 한국형 역기능우울척도를 중심으로

서동기,이순묵,김종남,최승원,채정민,정선호,조성경,김명기,Chad Ebesutani 한국심리학회 2019 한국심리학회지 일반 Vol.38 No.1

본 연구에서는 집단 연구용으로 개발된 한국형 역기능우울(dysfunctional depression)척도 20문항을 이용하여 단축형 검사 5문항을 선별하고 타당화하였다. 한국형 역기능우울척도의 단축형은 연구용 20문항 중 일부 문항(5문항)을 선별하여 제작된 것으로, 연구용 척도와 단축형 척도 모두 자기보고식 척도이다. 역기능우울척도는 역기능우울 상태를 측정하기 위한 것으로 일상우울의 상태가 심화되었거나 경우에 따라 일상우울에서는 없는 증상들을 측정하는 도구이다. 연구용 척도는 역기능우울에 대한 학술연구에서 집단수준에서의 추론을 위해 개발되었고, 단축형 척도는 주로 임상 및 상담 현장에서 개인의 역기능 우울 수준에 대한 신속한 진단을 위해 개발되었다. 즉 연구용 척도는 역기능우울에 대한 이론구축 및 관계구조 검증이 목적이 되고, 단축형 척도는 현장에서 개인의 역기능우울 상태를 신속하게 점검하는 것이 목적이다. 본 연구에서 개발한 단축형 척도의 신뢰도와 타당도는 척도의 내적 구조 분석과 기준점을 이용한 분류정확성과 분류일관성 지수에 의해 검정이 되었다. The purpose of this study was to develop a short form of the Korean dysfunctional depression scale (KDDS) and introduce methods for validation of the short form. The short form was developed by selecting five items from the original 20 items in the Korean dysfunctional depression scale. While the KDDS was developed to measure dysfunctional depression for the purpose of group research, the short form was developed for the practical use at individual levels. The scale for academic study was developed to infer the dysfunctional depression at the group level. So the short form can be widely used by practioners in industries, organizations, clinical/counselling settings for quick screening of potential patients suffering from dysfunctional depression. We demonstrated the reliability and validity of the short form by analyzing internal structure of the scale and providing classification accuracy and consistency.

태변성 복막염 : 산전 초음파 소견과 임상적 중요성 Prenatal Sonographic Findings and Their Clinical Significance

서동기,김성일,오수영,문정빈,김미하,박중신,전종관,윤보현,신희철 대한산부인과초음파학회 2000 대한산부인과초음파학회지 Vol.2 No.2

The accuracy and consistency of mastery for each content domain using the Rasch and deterministic inputs, noisy “and” gate diagnostic classification models: a simulation study and a real-world analysis using data from the Korean Medical Licensing Exami

서동기,Jae Kum Kim 한국보건의료인국가시험원 2021 보건의료교육평가 Vol.18 No.-

Purpose: Diagnostic classification models (DCMs) were developed to identify the mastery or non-mastery of the attributes required for solving test items, but their application has been limited to very low-level attributes, and the accuracy and consistency of high-level attributes using DCMs have rarely been reported compared with classical test theory (CTT) and item response theory models. This paper compared the accuracy of high-level attribute mastery between deterministic inputs, noisy “and” gate (DINA) and Rasch models, along with sub-scores based on CTT. Methods: First, a simulation study explored the effects of attribute length (number of items per attribute) and the correlations among attributes with respect to the accuracy of mastery. Second, a real-data study examined model and item fit and investigated the consistency of mastery for each attribute among the 3 models using the 2017 Korean Medical Licensing Examination with 360 items. Results: Accuracy of mastery increased with a higher number of items measuring each attribute across all conditions. The DINA model was more accurate than the CTT and Rasch models for attributes with high correlations (>0.5) and few items. In the real-data analysis, the DINA and Rasch models generally showed better item fits and appropriate model fit. The consistency of mastery between the Rasch and DINA models ranged from 0.541 to 0.633 and the correlations of person attribute scores between the Rasch and DINA models ranged from 0.579 to 0.786. Conclusion: Although all 3 models provide a mastery decision for each examinee, the individual mastery profile using the DINA model provides more accurate decisions for attributes with high correlations than the CTT and Rasch models. The DINA model can also be directly applied to tests with complex structures, unlike the CTT and Rasch models, and it provides different diagnostic information from the CTT and Rasch models.

폐면을 이용한 느타리버섯 재배

서동기 慶北大學校 農業開發大學院 2000 最高農業經營者課程 論文集 Vol.6 No.-

수평전도관에서 열전달에 의한 엔트로피발생에 관한 연구

서동기,김선정,권순석 대한기계학회 1987 대한기계학회 춘추학술대회 Vol.- No.-

가스상 HF 인증표준물질 개발

서동기,박정윤,이선영,최명기,이상호 한국분석과학회 2022 학술대회논문집 Vol.2022 No.5

Introduction to the LIVECAT web-based computerized adaptive testing platform

서동기,최정욱 한국보건의료인국가시험원 2020 보건의료교육평가 Vol.17 No.-

This study introduces LIVECAT, a web-based computerized adaptive testing platform. This platform provides many functions, including writing item content, managing an item bank, creating and administering a test, reporting test results, and providing informationabout a test and examinees. The LIVECAT provides examination administrators with an easy and flexible environment for composingand managing examinations. It is available at http://www.thecatkorea.com/. Several tools were used to program LIVECAT, as follows:operating system, Amazon Linux; web server, nginx 1.18; WAS, Apache Tomcat 8.5; database, Amazon RDMS—Maria DB; and languages, JAVA8, HTML5/CSS, Javascript, and jQuery. The LIVECAT platform can be used to implement several item response theory(IRT) models such as the Rasch and 1-, 2-, 3-parameter logistic models. The administrator can choose a specific model of test construction in LIVECAT. Multimedia data such as images, audio files, and movies can be uploaded to items in LIVECAT. Two scoring methods (maximum likelihood estimation and expected a posteriori) are available in LIVECAT and the maximum Fisher information itemselection method is applied to every IRT model in LIVECAT. The LIVECAT platform showed equal or better performance comparedwith a conventional test platform. The LIVECAT platform enables users without psychometric expertise to easily implement and perform computerized adaptive testing at their institutions. The most recent LIVECAT version only provides a dichotomous item response model and the basic components of CAT. Shortly, LIVECAT will include advanced functions, such as polytomous item response models, weighted likelihood estimation method, and content balancing method.

대구경 볼트와 와이어텐션을 이용한 슬래브 보강공법에 관한 실험적 연구

서동기,노현섭,김상모,이창남,김상섭 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

As time goes up, structural capacity of members decreases in reinforced concrete structures. The deterioration of the capacity is mainly due to the poor construction, corrosion of steel bars and the neutralization of concrete due to environmental pollution, etc. This deterioration is unavoidable, thus it is necessary to develop the method for repair and retrofit of structures in order to ensure structural safety of members. The purpose of this paper is to investigate the load-deflection, ultimate strength, failure mode, and energy absorption capacity of reinforced concrete slabs subject to load experimentally for several variables and grasp the problem of concrete slabs strengthened with large diameter bolts and wire tensioning. And propose foundational research data for4 strengthening reinforced concrete slabs. The test result shows that the capacity of anchorage is controlled by bearing capacity of concrete under the anchorage or punching shear around the anchorage. And the gap between bolts and core hole must be filled to prevent slip and rotation of anchorage.

A study on the reliability improvement of PAMS standard gas

서동기,김봄이,박정윤,이상호 한국분석과학회 2022 학술대회논문집 Vol.2022 No.11