The entire educational system is today highly concerned with the. Validation of a measure of knowledge about human papillomavirus hpv using item response theory and classical test theory jo waller a. In this sense, classical test theory ctt has been extensively serving the testing field for about 100 years. Educational and psychological measurement, 76, 325338. Classical test theory and item response theory analyses of. Item response theory irt vs classical test theory ctt.
It is a theory of testing based on the relationship between individuals performances on a test item and. Classical test theory ctt and item response theory irt classical test theory ctt and item response theory irt are testing item assessment approaches. Item response theory irt appears to be the currently prevailing paradigm within the psychometric theory. The study answered the following objectives\nspecifically. To provide comparisons and a worked example of item and scalelevel evaluations based on three psychometric methods used in patientreported outcome developmentclassical test theory ctt, item response theory irt, and rasch measurement theory rmtin an analysis of the national eye institute visual functioning questionnaire vfq25. Item response theory models student ability using question level performance instead of aggregate test level performance.
Item response theory another branch of psychometric theory is the item response theory irt. Comparisons between classical test theory and item response. Model linear non linear level test item assumption weak i. It is a theory of testing based on the relationship. We propose here that item response theory analyses complements the basic ctt techniques presented in janssen and meier 20. The practice of testing has become increasingly common and the reliance on information gained from test scores to make decision has made an indelible mark on our culture. The new psychometrics item response theory classical test theory is concerned with the reliability of a test and assumes that the items within the test are sampled at random from a domain of relevant items. Comparison of classical test theory and item response theory and their applications to test development ronald k. Through irt, the abilities or intelligence of people are said to be measurable through various mathematical models and techniques. The psychometric properties of the french version of this instrument were investigated in a crosssectional, multicenter study.
Using classical test theory, item response theory, and rasch. Chapter 8 the new psychometrics item response theory. Item reponses theory ctt testoriented indices like reliability are groupspecific scores are testspecific contribution of item measured using other items e. This chapter presents an overview of classical test theory ctt, strong true. Two main types of analytical strategies can be found for these data. This event was followed, shortly thereafter, bytheidea. Basics of classical test theory california state university. Item response theory provides powerful analytical tools that, even in their most basic applications, can be a valuable. In psychometrics, the theory has been superseded by the more sophisticated models in item response theory irt and generalizability theory g theory. But such relationships have rarely been empirically investigated, and, as a result, they are largely unknown. Clinical psychologists are advised to assess clinical and statistical significance when assessing change in individual patients. True t or f cross cultural fairness in testing has always been a critical factor in the development of tests. Item response theory is a newer theory with a focus on test items that adds more tools for solving measurement problems in psychology test bias adaptive testing item selection ctt focuses more on the total score of a scale or subscale. Comparison of classical test theory and item response.
Measurement theories are important to practice in educational measurement because they provide a background for addressing measurement problems. In psychometrics, item response theory irt also known as latent trait theory, strong true score theory, or modern mental test theory, is a paradigm for the design, analysis, and scoring of tests, questionnaires, and similar instruments measuring abilities, attitudes, or other variables. As its name indicates, irt primarily focuses on the item level information in contrast to the ctts. One of the most important problems is dealing with the measurement errors. Distinguishing differences compare and contrast topics from the lesson, such as classical test theory and item response theory making connections use understanding to explain the concept of. Classical test theory and item response theory comparison of the. Item response theory is a general statistical theory about examinee item and test performance and how performance relates to the abilities that are measured by the items in the test. Jul 15, 2015 item response theory is a general statistical theory about examinee item and test performance and how performance relates to the abilities that are measured by the items in the test. The conceptual foundations, assumptions, and extensions of the basic premises of ctt have allowed for the development of some excellent psychometrically sound scales. Summary this chapter presents an overview of classical test theory ctt, strong true. Two understandings of one highstakes performance exam.
Item response theory, graded response model, psychological assessment, affects background valid and reliable measures are essential to the field of psychology, as well as, to the study of abilities, aptitudes, and attitudes. Educational and psychological measurem june 1998 v58 n3. The present report demonstrates the difference between classical test theory ctt and item response theory irt approach using an actual test data for chemistry junior high school students. This study compared classical test theory ctt and item response theory irt. Despite theoretical differences between item response theory irt and classical test theory ctt, there is a lack of empirical knowledge about how, and to what extent, the irt and cttbased item and person statistics behave differently. Basics of classical test theory theory and assumptions types of reliability example classical test theory classical test theory ctt often called the true score model called classic relative to item response theory irt which is a more modern approach ctt describes a set of psychometric procedures used to test items and scales. Marlow a, kirsten mccaffery c, gregory zimet d a health behaviour research centre, department of epidemiology and public health, ucl gower street, london wc1e 6bt, uk b healthy communities research centre, faculty of health. Classical test theory and item response theory in automated assembly of parallel test forms the journal of technology, learning, and assessment volume 6, number 8 april 2008 a publication of the technology and assessment study collaborative caroline a. Pdf classical test theory ctt vs item response theory irt. Via a ctt and irt analysis it was found that both assessments are essentially equal in overall difficulty. Buchanan missouri state university summer 2016 this lecture covers item factor analysis and item response theory from the. Abstract item response theory irt is concerned with accurate test scoring and development of test items.
A primer on classical test theory and item response theory. However, this is only partially reflected in the psychometric practice. It is sometimes referred to as the strong true score theory or modern mental test theory because irt is a more recent body of theory and makes stronger assumptions as compared to classical test theory. Classical test theory analyses identified 5 of 10 communication items that did not perform well. Test dependent item response theory is essentially a nonlinear common factor model mcdonald, 1999, p. Classical test theory and item response theory 2016. Pdf test theory, classical test theory researchgate. Higher itemtest correlation is desired, which indicates that high ability examinees tend to get the item correct and low ability examinees tend to get the item incorrect. In psychometrics, item response theory irt also known as latent trait theory, strong true score theory, or modern mental test theory is a paradigm for the design, analysis, and scoring of tests, questionnaires, and similar instruments measuring abilities, attitudes, or other variables. To provide comparisons and a worked example of item and scalelevel evaluations based on three psychometric methods used in patientreported outcome development classical test theory ctt, item response theory irt, and rasch measurement theory rmtin an analysis of the national eye institute visual functioning questionnaire vfq25. Classical test theory an overview sciencedirect topics. An application of item response theory to psychological test. What it is and how you can use the irt procedure to apply it xinming an and yiufai yung, sas institute inc. Classical test theory is an influential theory of test scores in the social sciences.
However, whether irt or ctt would be the most appropriate method to analyse pro data remains unknown. Pdf a comparative study of classical theory ct and. Hambleton professor of education and psychology at the university of massachusetts, hills south, room 152, amherst, ma 01003. Classical test theory ctt and item response theory irt. Classical test theory assumptions, equations, limitations, and item analyses c lassical test theory ctt has been the foundation for measurement theory for over 80 years. T or f item response theory has the advantage over classical test theory in that it provides more detailed information regarding each item on a test. Irt, on the other hand, is more theory grounded and models the probabilistic distribution of examinees success at the item level. From classical test theory to item response theory and back. Item response theory irt, also called latent trait theory, is a psychometric theory that was created to better understand how individuals respond to individual items on psychological and educational tests. On the relationship between classical test theory and item. The following demonstrates a simulated dataset of 20 students true scores and their raw scores on a 10item test. Item response theory irt is all about your performance on an exam, and how it relates to individual items or questions on a test. Anothermilestonewaslaidin 1937 with the publication of the kuderrichardson formulas.
Using classical test theory, item response theory, and. Applying item response theory modeling in educational research. Irt is an example of what psychologists call a latent trait. The aim of this study is to introduce the jmetric program which is one of the open source programs that can be used in the context of item response theory and classical test theory. Eric ed466779 classical test theory and item response. The study aimed to examine the construct validity and reliability of the quality of life enjoyment and satisfaction questionnaireshort form qlesqsf according to both classical test and item response theories. The behavior of the item and person statistics derived from these two measurement frameworks was examined analytically and empirically using a data set obtained from bilog r. Despite its brevity, it has proved its value in classical test theory and item response theory assessments, the three traits have different correlates, and the measures appear to cover the range of subtraits e.
It is sometimes referred to as the strong true score theory or modern mental test theory because irt is a more recent body of theory and. The underlying theory is built around a series of mathematical formulas that have parameters that need to be estimated using complex statistical algorithms. The purposes of this instructional module are a to focus attention on the similarities and differences between classical test theory and item response theory and related. The frequently neglected and often misunderstood relationship between classical test theory and item response theory is discussed for the unidimensional case with binary measures and no guessing. Nov 30, 2010 this study compares the psychometric utility of classical test theory ctt and item response theory irt for scale construction with data from higher education student surveys. Educational and psychological measurem june 1998 v58 n3 p357. Applying item response theory modeling in educational research daitrang le iowa state university follow this and additional works at. Classical test theory vs item response theory by chris. Pdf a primer on classical test theory and item response theory for. It is pointed out that popular item response models can be directly obtained from classical test theory based models by accounting for the discrete. Internal consistency reliability estimates for the scales ranged from 0. Overview of classical test theory and item response theory. Item response theory and classical test theory university of hawaii. Item response theory painted a more promising picture than classical test theory for the 2 communication items that assessed access to an interpreter when needed.
The history, theoretical frameworks of classical test theory, item response theory irt, and the most common irt models used in modern testing are presented. A test theory model is necessary to help us better understand the relationship that exists between the observed or actual score on an examination and the underlying proficiency in the domain, which is generally unobserved. An ncme instructional module on comparison of classical test. Classical test theory ctt and item response theory irt are widely perceived as representing two very different measurement frameworks. Trait true score observed score classical test theory. Comparisons between classical test theory and item. Comparison of classical test theory and item response theory and their. May 31, 2015 classical test theory ctt and item response theory irt classical test theory ctt and item response theory irt are testing item assessment approaches. Article information, pdf download for item response theory and classical test. Psychometric theory offers two approaches in analyzing test data. Demonstrating the difference between classical test theory and item response theory using derived test data. Classical test theory vs item response theory by chris allred. Exploratory factor analysis \nvalidity principal component analysis \nreliability confirmatory factor analysis \ nclassical test theory structural equation modeling \ngeneralizability theory measurement invariance \nitem response theory computerized adaptive testing \nmanyfacet rasch model network psychometrics \n\n \nprice. Jan 23, 2014 item response theory or irt is a theory in psychometrics that is based on the assumption that individual answers or responses to questions have actual mathematical relationships.
The measurement models better known and used currently are mentioned, the classical test theory ctt, and item response theory irt, including the rasch model. Mar 25, 2010 patientsreported outcomes pro are increasingly used in clinical and epidemiological research. Aug 19, 2017 for the love of physics walter lewin may 16, 2011 duration. These measurement theories offer certain advantages over ctt, but they are more complex and depend on stronger assumptions. Using 2008 your first college year yfcy survey data from the cooperative institutional research program at the higher education research institute at ucla, two scales are built and testedone measuring social. On the relationship between classical test theory and item response theory.
Irt may be regarded as roughly synonymous with latent trait theory. Sep 09, 2009 this is in sharp contrast to classical test theory, where such an examinee would get a high test score on the easy test and vice versa under item response theory, the examinees ability is fixed and invariant with respect to the items used to measure it. Demonstrating the difference between classical test theory. Classical test theory and irt are widely used to address measurementrelated issues that arise from commonly used assessments in medical education, including. Classical test theory is based on a set of assumptions regarding the properties of test scores. Mde scrutinizes items with corrected itemtest correlation less than 0. Public access theses and dissertations from the college of education and human sciences. Item response theory postulates a nonlinear regression of a persons responses to a test item on his or her latent ability a concept that is similar to true score in ctt. Classical test theory ctt has served measurement practitioners for several decades as the foundation measurement theory. Individual change assessment can be conducted using either the methodologies of classical test theory ctt or item response theory irt. Reliability is seen as a characteristic of the test and of. Common test theory models include classical test theory ctt and item response theory irt. Whereas classical test theory focuses on the test as a whole, item response theory shifts its focus to the individual items questions themselves. However, few studies have empirically examined the.
You design test items to measure various kinds of abilities such as math ability, traits such as. Instead of assuming all questions contribute equivalently to our understanding of a students abilities, irt provides a mo. Application to truescore prediction from a possibly nonparallel test. Part of theinstructional media design commons, and thestatistics and probability commons. Classical test theory and item response theory the wiley. Another branch of psychometric theory is the item response theory irt. Approach 2 as an alternative approach for obtaining item response models from appropriate cttbased models or conversely, one can use the following procedure based on an important assumption made when fitting latent variable models to data from discrete observed measures, which is. Comparing classical test theory and item response theory.
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