Application Of Item Response Theory Research Articles

Investigating Approaches to Controlling Item Position Effects in Computerized Adaptive Tests

AbstractItem position effect (IPE) refers to situations where an item performs differently when it is administered in different positions on a test. The majority of previous research studies have focused on investigating IPE under linear testing. There is a lack of IPE research under adaptive testing. In addition, the existence of IPE might violate Item Response Theory (IRT)’s item parameter invariance assumption, which facilitates applications of IRT in various psychometric tasks such as computerized adaptive testing (CAT). Ignoring IPE might lead to issues such as inaccurate ability estimation in CAT. This article extends research on IPE by proposing and evaluating approaches to controlling position effects under an item‐level computerized adaptive test via a simulation study. The results show that adjusting IPE via a pretesting design (approach 3) or a pool design (approach 4) results in better ability estimation accuracy compared to no adjustment (baseline approach) and item‐level adjustment (approach 2). Practical implications of each approach as well as future research directions are discussed as well.

Increasing Sensitivity in Patient-Reported MDS-UPDRS Items for Predicting Medication Initiation in Early PD.

The MDS-UPDRS Parts IB and II are self-reported items providing a direct patient voice to the experiences of PD. To determine the most sensitive combination of MDS-UPDRS Parts IB and II items that accurately predicted the clinically relevant target of dopaminergic therapy initiation. Utilizing a longitudinal cohort of de novo non-treated PD patients, we applied item response theory (IRT) and survival analysis to assess the relationship between baseline patient-reported symptoms and the later initiation of dopaminergic therapy. The 20 MDS-UPDRS Parts IB and II items were analyzed for their relationship to PD severity (discrimination) and the amount of information they provided in this determination (information). These parameters were used to develop models of predictive accuracy for initiation of dopaminergic therapy. A six-item version showed a significantly higher C-index as compared to the full 20 item model (P = 0.001). This shortened version of the MDS-UPDRS contained only Part II items and provided a predictive accuracy for initiation of dopaminergic therapy better than the total combined scale score or any other combination. A six-item "Baseline Outcome Voice" version of patient-reported MDS-UPDRS items significantly increases the sensitivity of predicting the key future clinical outcome of starting dopaminergic treatment in early PD. This study also demonstrates how IRT modeling can provide information useful to refining existing measures to identify the most sensitive combination of items honoring the voice of the patient in determining key clinically pertinent decisions. Further research is needed to validate these findings in underrepresented populations.

Longitudinal Analysis of Natural History Progression of Rare and Ultra-Rare Cerebellar Ataxias Using Item Response Theory.

Degenerative cerebellar ataxias comprise a heterogeneous group of rare and ultra-rare genetic diseases. While disease-modifying treatments are now on the horizon for many ataxias, robust trial designs and analysis methods are lacking. To better inform trial designs, we applied item response theory (IRT) modeling to evaluate the natural history progression of several ataxias, assessed with the widely used scale for assessment and rating of ataxia (SARA). A longitudinal IRT model was built utilizing real-world data from the large autosomal recessive cerebellar ataxia (ARCA) registry. Disease progression was evaluated for the overall cohort as well as for the 10 most common ARCA genotypes. Sample sizes were calculated for simulated trials with autosomal recessive spastic ataxia Charlevoix-Saguenay (ARSACS) and polymerase gamma (POLG) ataxia, as showcased, across multiple design and analysis scenarios. Longitudinal IRT models were able to describe the changes in the latent variable underlying SARA as a function of time since ataxia onset for both the overall ARCA cohort and the common genotypes. The typical progression rates varied across genotypes between relatively high in POLG (~ 0.98 SARA points/year at SARA = 20) and very low in COQ8A ataxia (~ 0.003 SARA points/year at SARA = 20). Smaller trial sizes were required in case of faster progression, longer trials (~ 75-90% less with 5 years vs. 2 years), and larger drug effects (~ 70-80% less with 100% vs. 50% inhibition). Simulating under the developed IRT model, the longitudinal IRT model had the highest power, with a well-controlled type I error, compared to total score models or end-of-treatment analyses. The established longitudinal IRT framework allows efficient utilization of natural history data and ultimately facilitates the design and analysis of treatment trials in rare and ultra-rare genetic ataxias.

B - 130 Application of Item Response Theory to the MMPI-2-RF Response Bias Scale-19 (RBS-19)

Abstract Objective RBS is a cognitive overreporting scale on the MMPI-family of instruments. Recent efforts to refine the scale removed nine items lacking conceptual and empirical relationships to cognitive dysfunction (Ingram et al., 2024; Ratcliffe et al., 2022). This revised scale version (RBS-19) demonstrated improved utility and classification accuracy, although the improvements were small. Albertorio et al (2024) found that the RBS could be reduced to 14 items and identified potential “critical items”. This study uses IRT in a database of Active-Duty personnel to explore reduced item RBS forms. Method Using a 2-parameter IRT model, we examined cognitive overreporting across the 19-item MMPI-2-RF RBS-19 Scale. Participants (n = 326; 96% male) were divided into pass-all vs fail 2+ standalone PVTs for criterion-based comparisons (e.g., ROC analysis and mean difference), with indetermined profiles removed. Results Results indicate good theta coverage. Two items (24 and 26) were removed due to low α (2). RBS-14/17/19 all had similar AUC (0.72 vs 0.71 vs 0.72) and similar effect sizes between groups. Conclusions IRT analyses supported a 17-item RBS scale rather than the 14 or 19 item versions in this sample. However, no “critical items” emerged in this sample. Such differences may reflect changes in factor structure based on referral reason (Boress et al., 2023).

Pre-natal and early life lead exposure and childhood inhibitory control: an item response theory approach to improve measurement precision of inhibitory control

BackgroundNeurodevelopmental performance tasks are often separately analyzed, even when they tap into a similar construct. This may yield mixed findings for associations of an exposure-neurobehavioral outcome. We develop an item response theory (IRT) approach to integrate multiple task variables together to improve measurement precision of the underlying construct. We apply this approach to create an integrative measure of childhood inhibitory control, and study impacts of pre/post-natal lead exposure.MethodsUsing data from a prospective cohort based in Mexico (N = 533), we created an inhibitory control scale that integrates accuracy and reaction time information from four inhibitory control tasks (Go/NoGo Letter, Go/NoGo Neutral, Go/NoGo Happy, Delis-Kaplan Executive Function System (D-KEFS) Color-Word Interference Test, Condition 3). Using a generalized partial credit item response theory model, we estimated an inhibitory control index for each participant. We then assessed adjusted associations between umbilical cord blood and 4-year lead and childhood inhibitory control. We developed a resampling approach to incorporate error estimates from the inhibitory control variable to confirm the consistency of the lead-inhibitory control associations. We modeled time-varying associations of lead with each inhibitory control measure separately.ResultsParticipants had a median age of 9 years; 51.4% were males. Umbilical cord blood [-0.06 (95% CI: -0.11, -0.01)] and 4-year lead [-0.07 (95% CI: -0.12, -0.02)] were associated with inhibitory control index at 8–10 years. A resampling approach confirmed that 4-year lead was consistently associated with childhood inhibitory control index. Umbilical cord blood and 4-year lead were each associated with 3 out of 8 measures in separate models.ConclusionThis is the first application of IRT in environmental epidemiology to create a latent variable for inhibitory control that integrates accuracy and reaction time information from multiple, related tasks. This framework can be applied to other correlated neurobehavioral assessments or other phenotype data.

Item response theory validation of the Oxford knee score and Activity and Participation Questionnaire: a step toward a common metric

ObjectivesThe Oxford knee score (OKS) and OKS Activity and Participation Questionnaire (OKS-APQ) are patient-reported outcome measures used to assess people undergoing knee replacement surgery. They have not explicitly been tested for unidimensionality (whether they measure one underlying trait such as ‘knee health’). This study applied item response theory (IRT) to improve the validity of the instruments to optimize for ongoing use. Study Design and SettingParticipants undergoing primary total knee replacement (TKR) provided preoperative and postoperative responses for OKS and OKS-APQ. Confirmatory factor analysis (CFA) were performed on the OKS and OKS-APQ separately and then on both when pooled into one. An IRT model was fitted to the data. Results2972 individual response patterns were analyzed. CFA demonstrated that when combining OKS and OKS-APQ as one instrument, they measure one latent health trait. A user-friendly, free-to-use, web app has been developed to allow clinicians to upload raw data and instantly receive IRT scores. ConclusionsThe OKS and OKS-APQ can be combined to use effectively as a single instrument (producing a single score). For the separate OKS and OKS-APQ the original items and response options can continue to be posed to patients, and this study has confirmed the suitability of IRT-weighted scoring. Applying IRT to existing responses converts traditional sum scores into continuous measurements with greater granularity, including individual measurement error.

Characterizing social communication among minimally verbal children with autism: An application of item response theory.

Minimally verbal children constitute a portion of the autism spectrum. The paucity of proper measurement tools that sensitively and accurately assess behaviors has been one limiting factor in the improved knowledge of these children. Short of creating and validating a new measurement tool for this subpopulation, this study took an alternative and more immediate approach: conduct a secondary data analysis and examine an existing social communication measure, the Early Social Communication Scales (ESCS), with item response theory. The final sample consisted of 453 minimally verbal children culled from four different completed studies. The IRT models analyzed the frequency of social communication gestures from the ESCS and returned an objective difficulty hierarchy regarding initiations of joint attention and behavior regulation gestures. The best-fitting and final model was a zero-inflated negative binomial model (ZINBM), which determined that joint attention gestures were, on average, more difficult than behavior regulation gestures. Joint attentional shows and gives were essentially absent in the children's repertoire, and behavior regulation reaches were the easiest gestures for this sample. The ZINBM separately modeled children with some gestures and children who did not present with any gestures and determined that behavior regulation reaches and gives were likely the first gestures a child will eventually exhibit among children with no gestures. Methodological contributions and potential future applications of IRT are discussed.

Developing critical thinking test for adolescents: A validity and reliability study from the Czech Republic

This article presents a comprehensive validation study of a Critical Thinking Test (CTT) conducted among Czech adolescents in 2023. It offers valuable insights into the psychometric properties, correlations, and predictors associated with analytical, evaluative and inferential abilities of critical thinking. While there are tools available for measuring critical thinking, they tend to be lengthy and inaccessible in the Czech language. Our study seeks to address this gap by developing a concise and effective tool that students can complete within a single class period. Our study is based on a large sample of Czech adolescents in their first year of secondary school (N = 9,495), which allows us to apply Item Response Theory (IRT), which is the best method for validation. The results showed that the abbreviated 33-item version of the CTT is a reliable and valid instrument that measures three distinct abilities (analysis, evaluation, and inference) that are highly correlated. Limitations and implications for the use of the instrument are discussed.

Item response theory in building environment engineering: A novel approach to identifying key residential environment items

The residential environment significantly influences residents’ health, quality of life, and well-being. Therefore, it is essential to assess the residential environment and implement improvement measures when problems are identified. In this context, the use of assessment tools such as BREEAM, LEED, and CASBEE has increased rapidly in recent years. Identifying key items with these assessment tools is crucial for prioritizing improvements to residential environment. This study introduces the novel application of item response theory (IRT) to building environment engineering data in order to identify key items from the CASBEE Residential Health Checklist. The strength of IRT lies in its ability to consider variations in scores for each item and the relative relationships between items, thereby enabling the identification of significantly influential key items. Examining Japanese residences, IRT identified 6 environmental items and 7 spatial items from a total of 44 items in the CASBEE Residential Health Checklist. Additionally, these environmental and spatial components were ranked by their explanatory power for the overall assessment of the residential environment. These findings contribute to prioritizing improvements in residential environments and provide a brief assessment method. IRT can be applied to other regions and building types, potentially enabling the identification of key items unique to each case. Thus, IRT is a versatile method with broad applicability for identifying key items in residential environment assessments.

Modeling of Colorado Learning Attitude Science Survey in Indonesian Version: A Study with Applying Item Response Theory

Modeling of Colorado Learning Attitude Science Survey in Indonesian Version: A Study with Applying Item Response Theory

Reliability and validity of simple Chinese version of grit scale for elementary school students

BackgroundThe Grit scale (GS-12) is a widely used rating scale that assess passion and perseverance. The present study aimed to evaluate the reliability and validity of simple Chinese Version of Grit Scale (GS-SC) among Chinese adolescents.MethodsSeven hundred one primary school students were recruited as Sample 1. Item analysis and exploratory factor analysis (EFA) were conducted on Sample 1 to preliminarily examine the structure of the scale. Sample 2 consisted of 5,384 primary school students. Confirmatory factor analysis (CFA) and verification of reliability and validity were conducted on Sample 2 to establish a formal scale and further verify the psychometric properties by applying item response theory (IRT).ResultsEFA and CFA revealed a clear two-factor structure. The results demonstrated that the Simplified Chinese Version of Grit Scale had adequate internal consistency and re-test reliability. GS-CS also showed good criterion-validity with personality, self-control, effort regulation and academic achievement. Furthermore, all the items show a acceptable fit to the GRM and have good discrimination (ranging from 2.13 to 3.45) and moderate difficulty(ranging from-1.58 to 0.95).ConclusionsThe reliability and validity of the GS-SC are good, indicating that the scale can be used as an effective tool for measuring the grit of primary school students in China.

Measuring risky loot box use: An item response theory analysis of the Risky Loot Box Index among adolescents.

Loot boxes (LBs) are virtual items embedded within video games that contain randomly generated in-game prizes. LB use can become risky, so it is important to have good measurement instruments, especially among adolescents, who are particularly involved in video gaming and LB purchasing. The present study analyses the adequacy of the Risky Loot Box Index (RLI; Brooks & Clark, 2019) by applying item response theory (IRT). Participants were 2,443 (59% males, mean age = 16.48, SD = 1.22) Italian high school students. The 2PL logistic model was applied. Item properties (i.e., severity and discrimination) were consistent with the aim of efficiently measuring risky LB use. The test information function indicated that the instrument was adequately informative. The RLI appeared to be invariant across gender, with male adolescents more at-risk than female adolescents. LB engagement was also found to explain latent trait of risky LB use over and beyond video gaming and gambling frequency and severity when controlling for gender. The RLI is an efficient screening tool that can specifically measure risky LB use among youth. It can profitably be used for research and intervention purposes. The promising usefulness of the IRT score for clinical purposes is also discussed. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Item Response Theory Validation of the Forgotten Joint Score for Persons Undergoing Total Knee Replacement.

The Forgotten Joint Score (FJS), a commonly used patient-reported outcome measure, was developed without fully confirming assumptions such as unidimensionality (all items reflect 1 underlying factor), appropriate weighting of each item in scoring, absence of differential item functioning (in which different groups, e.g., men and women, respond differently), local dependence (pairs of items are measuring only 1 underlying factor), and monotonicity (persons with higher function have a higher score). We applied item response theory (IRT) to perform validation of the FJS according to contemporary standards, and thus support its ongoing use. We aimed to confirm that the FJS reflects a single latent trait. In addition, we aimed to determine whether an IRT model could be fitted to the FJS. Participants undergoing primary total knee replacement provided responses to the FJS items preoperatively and at 6 and 12 months postoperatively. An exploratory factor analysis (EFA), confirmatory factor analysis (CFA), and Mokken analysis were conducted. A graded response model (GRM) was fitted to the data. A total of 1,774 patient responses were analyzed. EFA indicated a 1-factor model (all 12 items reflecting 1 underlying trait). CFA demonstrated an excellent model fit. Items did not have equal weighting. The FJS demonstrated good monotonicity and no differential item functioning by sex, age, or body mass index. GRM parameters are reported in this paper. The FJS meets key validity assumptions, supporting its use in clinical practice and research. The IRT-adapted FJS has potential advantages over the traditional FJS: it provides continuous measurements with finer granularity between health states, includes individual measurement error, and can compute scores despite more missing data (with only 1 response required to estimate a score). It can be applied retrospectively to existing data sets or used to deliver individualized computerized adaptive tests. Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Genetic associations with dementia-related proteinopathy: Application of item response theory.

Although dementia-related proteinopathy has a strong negative impact on public health, and is highly heritable, understanding of the related genetic architecture is incomplete. We applied multidimensional generalized partial credit modeling (GPCM) to test genetic associations with dementia-related proteinopathies. Data were analyzed to identify candidate single nucleotide variants for the following proteinopathies: Aβ, tau, α-synuclein, and TDP-43. Final included data comprised 966 participants with neuropathologic and WGS data. Three continuous latent outcomes were constructed, corresponding to TDP-43-, Aβ/Tau-, and α-synuclein-related neuropathology endophenotype scores. This approach helped validate known genotype/phenotype associations: for example, TMEM106B and GRN were risk alleles for TDP-43 pathology; and GBA for α-synuclein/Lewy bodies. Novel suggestive proteinopathy-linked alleles were also discovered, including several (SDHAF1, TMEM68, and ARHGEF28) with colocalization analyses and/or high degrees of biologic credibility. A novel methodology using GPCM enabled insights into gene candidates for driving misfolded proteinopathies. Latent factor scores for proteinopathies were estimated using a generalized partial credit model. The three latent continuous scores corresponded well with proteinopathy severity. Novel genes associated with proteinopathies were identified. Several genes had high degrees of biologic credibility for dementia risk factors.

Genotype-Environment Interaction in ADHD: Genetic Predisposition Determines the Extent to Which Environmental Influences Explain Variability in the Symptom Dimensions Hyperactivity and Inattention

Although earlier research has shown that individual differences on the spectrum of attention deficit hyperactivity disorder (ADHD) are highly heritable, emerging evidence suggests that symptoms are associated with complex interactions between genes and environmental influences. This study investigated whether a genetic predisposition [Note that the term ‘genetic predisposition’ was used in this manuscript to refer to an estimate based on twin modeling (an individual’s score on the latent trait that resembles additive genetic influences) in the particular population being examined.] for the symptom dimensions hyperactivity and inattention determines the extent to which unique-environmental influences explain variability in these symptoms. To this purpose, we analysed a sample drawn from the Twins Early Development Study (TEDS) that consisted of item-level scores of 2168 16-year-old twin pairs who completed both the Strengths and Difficulties Questionnaire (SDQ; Goodman, in J Child Psychol Psychiatry 38:581–586, 1997) and the Strength and Weaknesses of ADHD Symptoms and Normal Behavior (SWAN; Swanson, in Paper presented at the meeting of the American Psychological Association, Los Angeles, 1981) questionnaire. To maximize the psychometric information to measure ADHD symptoms, psychometric analyses were performed to investigate whether the items from the two questionnaires could be combined to form two longer subscales. In the estimation of genotype-environment interaction, we corrected for error variance heterogeneity in the measurement of ADHD symptoms through the application of item response theory (IRT) measurement models. A positive interaction was found for both hyperactivity (e.g., β1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\beta }_{1}$$\\end{document} = 2.20 with 95% highest posterior density interval equal to [1.79;2.65] and effect size equal to 3.00) and inattention (e.g., β1\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${\\beta }_{1}$$\\end{document} = 2.16 with 95% highest posterior density interval equal to [1.56;2.79] and effect size equal to 3.07). These results indicate that unique-environmental influences were more important in creating individual differences in both hyperactivity and inattention for twins with a genetic predisposition for these symptoms than for twins without such a predisposition.

종단 문항반응이론 기반 성장모형의 적용을 통한 중학생의 진로성숙도 변화 분석

With an emphasis on career education, career maturity has emerged as an important variable that, prompts analyses of its growth and changes. Previous studies examining career maturity longitudinally used raw scores as variables, which inevitably included errors. However, the application of the longitudinal item response theory allows for error-free growth modeling. In this study, longitudinal measurement invariance was confirmed by applying item response theory, and the feasibility of simultaneous analyses of items and information functions was demonstrated. In addition, to understand the changes in students' career maturity, a multi-group analysis by gender was conducted along with a linear growth model based on the longitudinal item response theory, which is a longitudinal extension of the item response theory. The results indicated that the items on the career maturity scale were generally acceptable. However, there was a lack of information to measure high levels of career maturity among first-year middle students. Career maturity in middle school exhibited a linear declining trend. In the multi-group analysis, female students showed lower initial levels than male students, but the decline was less pronounced. An interpretation and discussion of the research results, along with the limitations and suggestions for future research, are provided.

Genetic associations with mixed neuropathologies in the aging brainGenetic associations with mixed neuropathologies in the aging brain

AbstractBackground““Mixed” neuropathologies (NPs) are common in aged brains. Classic Alzheimer’s disease neuropathologic change (ADNC) proteinopathies are amyloid‐β plaques and tau neurofibrillary tangles (NFTs). In addition, α‐synuclein and TDP‐43 are also key proteinaceous disease markers, and cerebrovascular diseases (CVDs) often coexist. Although the scientific problems regarding mixed NPs are increasingly recognized, genetic associations with mixed NPs have not been well‐investigated. In this study, we applied item response theory (IRT) to optimize the clustering and combination of mixed NPs and examined the genetic associations.MethodNP data were drawn from the National Alzheimer’s Coordinating Center (NACC) NP v10‐11 forms through the March 2022 data freeze, including Thal phase ratings (A score); Braak NFT stage (B score); CERAD neuritic plaque scores (C score); Lewy bodies (LBs); TDP‐43; hippocampal sclerosis (HS); cerebral amyloid angiopathy (CAA); infarct and lacunes; microinfarcts; atherosclerosis of the circle of Willis; and brain arteriolosclerosis. We determined dominant pathology patterns in 1,228 participants who had no missing data using a multidimensional graded response model within the IRT framework. The NACC NP data were linked to the U.S. Alzheimer’s Disease Research Centers genetic data provided by the Alzheimer’s Disease genetic Consortium.ResultFrom the leave one out cross validation simulation, the model fitness tests showed that the 4‐factor model had fewer differences from the data than the other models. As shown in Figure, the predominant NPs were TDP‐43 and HS for factor 1 (F1), CVDs other than CAA for factor 2 (F2), A, B, and C scores and CAA for factor 3 (F3), and LBs for factor 4 (F4). The TMEM106B locus was genome‐wide significant with F1 (TDP‐43/HS) and the APOE locus was genome‐wide significant with F3 (ADNC/CAA) after adjusted for age at death, sex, and other factor scores. The SDK1 and FMNL2 loci were not genome‐wide significant, but had noteworthy associations with F2 (CVDs).ConclusionOur new approach to create mixed NP scores could detect the TMEM106B and APOE loci as TDP‐43/HS related and ADNC related regions, respectively. Although previous studies reported SDK1 as an ADNC related gene, we showed that the gene may be associated with CVDs.

Development and Validation of the Brief Math Anxiety Scale (BMAS) in University Students.

This study developed the Brief Math Anxiety Scale (BMAS), a brief version of the Shortened Math Anxiety Rating Scale (sMARS), maintaining its original three-factor structure, by applying item response theory. The sMARS was administered to 1,349 undergraduates, along with other questionnaires to measure their math ability, trait and test anxieties, and attitudes toward mathematics. Results showed that the original scale could be reduced to nine items (three for each subscale). We provided evidence of good psychometric properties: strong internal consistency, adequate 7-week test-retest reliability, and good convergent/discriminant validity. In conclusion, the BMAS provides valid interpretations and reliable scores for assessing math anxiety in university students, and is especially useful in situations with time constraints where the longer form is impractical.

Psychometric Evaluation of the Affective Reactivity Index Among Children and Adolescents in China: A Multi-Method Assessment Approach.

The Affective Reactivity Index (ARI) is one of the most studied scales for assessing youth irritability, but little is known about its measurement performance in community populations. This study applied item response theory (IRT), network analysis, and classical test theory (CTT) to examine the psychometric properties of the ARI in a sample of n = 395 community-based children (Mage = 13.44, SD = 2.51) and n = 403 parents. In this sample, the ARI demonstrated good reliability, as well as convergent and concurrent validity. The one-factor structure was supported by both confirmatory factor analysis (CFA) and network analysis. IRT analysis revealed that the ARI effectively distinguished between various levels of irritability within the community population. Network analysis identified "Loses temper easily,""Gets angry frequently," and "Often loses temper" are central aspects of irritability. The findings support the ARI as a brief, reliable, and valid instrument to assess irritability in community children and adolescents.

Application of Item Response Theory as a Modern Statistical Tool to Test Item Development and Analysis

In the educational and psychological testing, there are two major theories through which tests can be developed, validated and ultimately used for assessing examinee’s performance. These are classical test theory (CTT) and item response theory (IRT) and their corresponding models. Item Response Theory (IRT) as a test theory came into existence to provide probabilistic approach to surmount some of the inherent limitations of the classical test theory and maximize objectivity in educational assessment. Item response theory (IRT) is a quantitative approach to testing the reliability and validity of an instrument based on its items. It has statistics for evaluating individual items from a quantitative perspective. The purpose of this paper is to describe in details, the application of item response theory in test item development and analysis. The reason for the application of IRT is to have test items that will yield a reasonable degree of reliability. The statistics used in this respect are – item difficulty parameter, which is a measure of the proportion of testees who responded to an item correctly; the item discrimination parameter, which is the measure of how well the items discriminate between examinees with high and low levels of knowledge or ability and pseudo-guessing parameter, which expresses the probability that an examinee with low ability can be able to get an item correctly. The acceptable range of values of the aforementioned parameters were also discussed.