Practical Significance of Item Response Theory Model Misfit:Much Ado About Nothing?

This thesis centers around practical applications of psychological, educational, and health assessment. In psychometric testing, complex statistical equations are often used to approximate individuals’ levels of the measured characteristic, based on their response patterns. These levels (or scores) are then used to draw conclusions and to make decisions regarding the tested individuals. For instance, a psychologist might calculate a child’s score on an attention problems test to assess whether the child experiences attention deficits; a university might use the scores on an admission exam in order to select students; or a clinician might use patients’ scores on a physical functioning test in order to assess their overall health. More often than not, the statistical models that are used to calculate the scores do not describe the reality (i.e., individuals’ response patterns) very well. This, in turn, might affect the accuracy of the calculated scores. The overarching question that I strived to answer in this thesis was: Are the decisions that are made based on these scores (e.g., classifying a child as suffering from attention deficit, admitting certain applicants into a study program, or classifying a person as physically disabled) affected by the fallacy of the used model? And if so, to what extent? This question is important for test constructors and researchers who wish to create and use high-quality psychometric instruments. The findings showed that, in general, decisions were only marginally influenced by the imperfect fit of the models used. The research presented in this thesis have important implications for everyone involved in psychometric testing, from test constructors to test takers

USING ONLINE ASSESSMENT AS A TOOL FOR LEARNING

The use of information and communication technologies in education offers new means of evaluation and examination. e-Testing is a valuable evaluation tool that teachers can use during final exams and students can exploit for self-assessment, in order to ge-Learning, online assessment, e-assessment, web based learning

ASPECTS ABOUT SIMULATED MODEL TRUSTINESS

Nowadays, grace of computing possibilities that electronic computers offer and namely, big memory volume and computing speed, there is the improving of modeling methods, an important role having complex system modeling using simulation techniques. These osimulation model, validation, sensitivity analysis

E-GOVERNMENT: A DRIVING FACTOR FOR STIMULATING INNOVATION PERFORMANCE IN ROMANIA?

The development of public services is one of the priorities on the agendas of all policies, both national and European. One of the most recent concerns of the European Commission, as shown in the 2010 Innobarometer, is to find ways and develop strategies to support the innovation in the public administration sector, in the context of the continuously changing economic background. In this paper, we'll investigate the relationship between e-Government, and the overall innovation performance at national level, for some European Union countries. e-Government is already a known concept, widespread in the world, promoting the implementation of information and communication technologies in the public administration, in order to provide better public services to citizens and businesses. A main component of the e-Government concept is the "counter reform", aimed to streamlining administrative act quickly in order to respond to the demands of citizens, businesses and government structures. Innovation in e-Government will be measured with two Eurostat indicators - "e-Government on-line availability" and "e-Government usage by individuals" - while for the overall innovation performance we'll use a composite indicator - the Summary Innovation Index (SII) - from the Innovation Union Scoreboard (IUS). In Romania, even if the values of these indicators are not at the level of other EU countries, we can say that the situation has improved and electronic public services are being used increasingly often. The study also includes a comparison between two "modest innovators": Romania and Bulgaria. Regarding the overall innovation performance, according to the 2010 Innovation Union Scoreboard ranking, Romania is the leader of the "modest innovators" countries, overcoming Latvia, Bulgaria and Lithuania. However, in the field of e-Government our country has major shortcomings. Romania has registered a significant progress in the years after the EU integration, followed by a setback in 2009, still having values below those of other EU countries, including Bulgaria.innovation, e-Government, public sector, SII, correlation

ICT DETERMINING FACTORS IN INCREASING THE INNOVATION IN ROMANIA

In order to develop competitiveness, to strengthen the economic position in front of the social challenges of the 21st century (which include: climate changes, energy resources, health and aging), large and sustained efforts are made at the European Union level regarding the innovation. This paper investigates how the frequency of computer use by individuals can be linked to the innovation level, in order to establish an ICT determining factor for growing the innovation. The results show that the encouragement of ICT absorption by the individuals can yield to a growth in the innovation level, thus minimizing the gap between Romania and the European Union developed countries.innovation, ICT, correlation, UE 2020 initiative

The crit coefficient in Mokken scale analysis:A simulation study and an application in quality-of-life research

PURPOSE: In Mokken scaling, the Crit index was proposed and is sometimes used as evidence (or lack thereof) of violations of some common model assumptions. The main goal of our study was twofold: To make the formulation of the Crit index explicit and accessible, and to investigate its distribution under various measurement conditions. METHODS: We conducted two simulation studies in the context of dichotomously scored item responses. We manipulated the type of assumption violation, the proportion of violating items, sample size, and quality. False positive rates and power to detect assumption violations were our main outcome variables. Furthermore, we used the Crit coefficient in a Mokken scale analysis to a set of responses to the General Health Questionnaire (GHQ-12), a self-administered questionnaire for assessing current mental health. RESULTS: We found that the false positive rates of Crit were close to the nominal rate in most conditions, and that power to detect misfit depended on the sample size, type of violation, and number of assumption-violating items. Overall, in small samples Crit lacked the power to detect misfit, and in larger samples power differed considerably depending on the type of violation and proportion of misfitting items. Furthermore, we also found in our empirical example that even in large samples the Crit index may fail to detect assumption violations. DISCUSSION: Even in large samples, the Crit coefficient showed limited usefulness for detecting moderate and severe violations of monotonicity. Our findings are relevant to researchers and practitioners who use Mokken scaling for scale and questionnaire construction and revision. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11136-021-02924-z

Investigating the practical consequences of model misfit in unidimensional IRT models

In this article, the practical consequences of violations of unidimensionality on selection decisions in the framework of unidimensional item response theory (IRT) models are investigated based on simulated data. The factors manipulated include the severity of violations, the proportion of misfitting items, and test length. The outcomes that were considered are the precision and accuracy of the estimated model parameters, the correlations of estimated ability ([Formula: see text]) and number-correct ([Formula: see text]) scores with the true ability ([Formula: see text]), the ranks of the examinees and the overlap between sets of examinees selected based on either [Formula: see text], [Formula: see text], or [Formula: see text] scores, and the bias in criterion-related validity estimates. Results show that the [Formula: see text] values were unbiased by violations of unidimensionality, but their precision decreased as multidimensionality and the proportion of misfitting items increased; the estimated item parameters were robust to violations of unidimensionality. The correlations between [Formula: see text], [Formula: see text], and [Formula: see text] scores, the agreement between the three selection criteria, and the accuracy of criterion-related validity estimates are all negatively affected, to some extent, by increasing levels of multidimensionality and the proportion of misfitting items. However, removing the misfitting items only improved the results in the case of severe multidimensionality and large proportion of misfitting items, and deteriorated them otherwise

Preliminary investigation of common GSK3, PPARγ AND DPP IV chemical space

Cross-target biochemical experiments demonstrated that some molecules display an ample spectrum of biological activities which are therapeutically effective. In this regard we investigated the chemical space of the following targets GSK3, DPP IV and PPAR gamma since the DPP IV inhibitors, and PPAR gamma agonists are used to treat diabetes miellitus of type 2. Nevertheless, GSK-3 inhibitors have shown therapeutic potential for insulin resistant type-2 diabetes, the drug market does not register yet an inhibitor of GSK-2 for therapeutical use. The ChEMBL homo sapiens assay data for GSK-3, DPP IV and PPAR gamma were assembled into are database including 7599 compounds. GSK-3 assay comprise 2497 compounds, from which 1889 are unique divided into 428 chemotypes. DPP IV register 3482 compounds and 3026 were unique sharing 510 chemotypes. PPAR gamma incldes 1620 agonists from which 1333 are unique partitioned into 264 chemotypes. The chemical space of GSK3, DPP IV and PPAR gamma share 12 chemotypes, GSK3 and DPP IV share 30 chemotypes, DPP IV and PPAR gamma share 13 chemotypes, whereas GSK3 and PPAR gamma share 17 chemotypes. The 12 chemotypes active on all three proteins were superposed to develop a common pharmacophore which will be further used to identify novel chemotyes with potential biological activity

Partial least squares model of moulting accelerating compounds with insecticide activity against lepidopteran species

In this study the insecticidal activity of a series of 33 dibenzoylhydrazinederivatives, expressed as the pEC50activity measured in vitro, based on an ecdysone-dependent reporter assay using cell lines derived from one lepidopteran species (the cotton leafworm Spodoptera littoralis), was correlated with structural descriptors using the partial least squares (PLS) approach. The data set was energy pre-optimized by molecular mechanics calculations using the MMFF94s force field. Several 0D, 1D, 2D and 3D descriptors were calculated for the minimum energy conformers. A two-components PLS model was obtained with acceptable statistical quality (R2X(Cum) = 0.705, R2Y(cum) = 0.821 and Q2 (Cum) = 0.793) for modeling the insecticidal activity. The model goodness of fit tested with the Y-randomization test indicated a stable model. Specific dibenzoylhydrazine structural features supplying information about topological distances and descriptors sensitive to any conformational change influence the insecticidal activity