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. It is a theory of testing based on the relationship. In many achievement testing situations it is useful or sometime required to. Based upon items rather than test scores, the new approach was known as item response theory. Item response theory and computerized adaptive testing. An application of item response theory to psychological test. Traditional testing procedures typically utilize unidimensional item response theory irt models to provide a single, continuous estimate of a students overall ability.
Download citation item response theory in language testing language test tasks and items are particularly susceptive to factors that make responses by. Combining item response theory and diagnostic classification. If participant wealth item cost, we should see a positive item response level of positive item response tells us about where on the scale the participant lies, e. Lord of the educational testing service has been the driving force behind both the development of the theory and its application for the past 50 years. While irt is not new, its application in speech language. The final part covers the principles of language testing. Item response theory and the assumption of unidimensionality. A simple guide to the item response theory irt and rasch.
In its simplest form, item response theory posits that the probability of a random person j with ability. Psychometric theory offers two approaches in analyzing test data. Additionally, reliability and dependability as well as the scoring of performance tests are covered. Classical test theory ctt and item response theory irt. Validity of the three parameter item response theory model.
Irt provides a foundation for statistical methods that are utilized in contexts such as test development, item analysis, equating, item banking, and computerized adaptive testing. When frank baker wrote his classic the basics of item response theory in 1985, the field of educational assessment was dominated by classical test theory based on test scores. Modeldata fit studies welcome to the ideals repository. This paper aims to provide a didactic application of irt and to highlight some of these advantages for psychological test development. Irt is the statistical basis for analyzing multiplechoice survey or test data for researchers, social scientists, and others who want to. This book intends to provide a theoretical overview as well as to give practical guidance concerning the application of irt in item bank building in a language testing context. 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 evaluation of a languageindependent cs1 knowl edge assessment. Item response theory in language testing researchgate. The different options afforded to language testers are outlined and demonstrated with a working example taken from an authentic foreign language test. Irt cat environment, and illustrated in the context of language testing. This course introduces item response theory irt applied to both dichotomous twooutcome data and polytomous multiple outcome data.
Reliability in language testing linkedin slideshare. Ctt and irt 5 scores, because we might apply ctt to one item tests and then it is a theory about item scores. 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. In an issue of an early volume of applied measurement in education, eignor. Introduction to classical test theory ji zeng and adam wyse. K r azavipour the routledge handbook of language testing.
Item response theory irt represents an important innovation in the field of psychometrics. It covered basic concepts, comparison to ctt methods, relative efficiency, optimal number of choices per item, flexilevel tests, multistage tests, tailored testing. Questionnaire development and cognitive testing using item. Item response theory irt is arguably one of the most in. In classical test theory, items on a scale measuring a single construct are generally considered to be equivalent to each other. Irt may be regarded as roughly synonymous with latent trait theory. A subset of reading comprehension items is analyzed with the use of a classical test theory item analysis approach, which is contrasted with rasch, two. Item response theory irt, also known as latent trait theory or modern mental test theory. Language test tasks and items are particularly susceptive to factors that make responses by test candidates ambiguous. Item response theory irt is a set of statistical methods that are increasingly used for developing instruments in speech language pathology. Item response theory and the assumption of unidimensionality for language tests grant henning, thom hudson, and jean turner language testing 1985 2. The topics, organization, and presentation are those used in a 4week seminar held each summer for the past several years. Item response theory statistical methods training course. Irt is the statistical basis for analyzing multiplechoice survey or test data for researchers, social scientists, and others who want to create better scales, tests, and questionnaires.
Item response theory irt item response theory consists of any model relating the probability of an examinees response to a test item to an underlying ability hmirt, p. 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. Next, we consider how irt has been used in clinical research for. Item response theory in r using package ltm dimitris rizopoulos department of biostatistics, erasmus university medical center, the netherlands d.
Classical test theory ctt, generalizability theory gtheory, item response theory irt, and differential item functioning dif. This book explores the appropriateness of item response theory irt in language testing. Item response theory, item response models, testing practices. Item response theory, though it has become a widely recognized tool in language testing research, is still not used frequently in practical language assessment projects. An application of item response theory to psychological. 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. The item response theory irt also known as latent trait theory, is used for the development, evaluation and administration of standardized measurements. Whereas classical test theory focuses on the test as a whole, item response theory shifts its focus to the individual items questions themselves. Another branch of psychometric theory is the item response theory irt. This paper attempts to familiarize the readers with such reliability camps.
His work with the ets had impacts on the law school admissions test, the test of english as a foreign language, and the graduate record exam. Item response theory was an upstart whose popular acceptance lagged in part because the. Test dependent item response theory is essentially a nonlinear common factor model mcdonald, 1999, p. Item characteristic curve in one to three parameter models iii. Assuming a nonparametric family of item response theory models, a theorybased procedure for testing the hypothesis of unidimensionality of the latent space is proposed. Item information function and test information function iv. This paper marks the beginning of item response theory as a measurement theory. The focus of the present chapter is to introduce different options for undertaking item analysis, with particular focus on item response theory. The role of item response theory irt in determining the validity of second language tests is examined in the case of one specific test, the listening subtest of the occupational english test oet, used in australia to measure the language skills of nonnative englishspeaking health professionals. Comparisons between classical test theory and item response. Understanding item analyses item analysis is a process which examines student responses to individual test items questions in order to assess the quality of those items and of the test as a whole. It is called latent trait theory attempting to predict observations from places on latent variable. The penultimate part addresses test administration, as well as interlocutor and rater training. Birnbaums three parameter logistic item response theory 3pl irt model is.
Item response theory each individual item can be used for comparison purposes person endorses better rating on hard itemsthe person is higher on the trait person endorses worse rating on easy items the person is lower on the trait items that measure the same construct can be aggregated into longer assessments. An application of item response theory to language testing. In part seven, various theories of language testing including classical test theory, generalizability theory, and item response theory are discussed in separate chapters. It investigates the dimensionality of the reading tests of the cambridge first certificate of english test fce and the test of english as a foreign language toefl, and the relative fit of 1, 2, 3 parameter irt models in which the rasch model is closely examined.
University of groningen applications of item response theory. Irt was applied to two scales a positive and a negative affect. The material is organized to facilitate understanding. Item calibration and ability estimation unlike the classical test theory, in which the test scores of the same examinees may vary from test to test, depending upon the test difficulty, in irt item parameter calibration is samplefree while examinee proficiency estimation is item. Additionally, reliability and dependability as well as the scoring of performance tests are. Most of the irt models make the specific assumption that the items in a test measure a single, or unidimensional ability or trait, and that the items form a unidimensional scale of measurement item characteristic curve.
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. It provides a forum for the exchange of ideas and information between people working in the fields of first and second language testing and assessment. Building an evaluation scale using item response theory acl. Apr 18, 2016 item response theory irt has become a popular methodological framework for modeling response data from assessments in education and health. Item response theory is a measurement framework used in the design and analysis of educational and psychological assessments achievement tests, rating scales, inventories, or other instruments that measure mental traits. Each specific irt model makes specific assumptions about the relationship between the test takers ability and his performances on a given item. Language testing professionals and teacher educators have articulated the need for a broad variety stakeholdersincluding classroom teachers to develop. Mar 08, 2015 itemresponse theory because of the limitations in ctstheory and gtheory, psychometricians have developed a number of mathematical models for relating an individuals test performance to that individuals level of ability. Pdf applying item response theory in language test item. Over the last 30 years item response theory irt has essentially replaced traditional classical test theory approaches to designing, evaluating, and scoring largescale tests of cognitive ability. You will see the value in applying item response theory, possibly in your own organization. Each specific irt model makes specific assumptions about the.
Item response theory the unidimensionality assumption. Thus, the use of multidimensional item response theory in composite score creation may provide better composite estimates. Item selection using ctt and irt with unrepresentative samples. Applying item response theory in language test item bank building. It is widely used in education to calibrate and evaluate items in tests, questionnaires, and other. Novick on test theory, which was an expansion of his dissertation. Results indi cate that although the language awareness test contains items with different response formats, only one latent trait is measured. Item response theory irt is arguably one of the most influential developments in the field of educational and psychological measurement. Pdf test theory, classical test theory researchgate. An introductory 3day course introducing item response theory measurement models applied to psychological and educational data. 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. In connection to language testing, there are four such camps. Demonstrating the difference between classical test theory.
The role of item response theory in language test validation. Item response theory irt is concerned with accurate test scoring and development of test items. Applying item response theory in language test item bank. The basics of item response theory using r statistics for. Questionnaire development and cognitive testing using item response theory irt. Understanding item analyses office of educational assessment.
This entry discusses some fundamental and theoretical aspects of irt and illustrates these with worked examples. Testing service ets, where he would work for 33 years. Item response theory has become an essential component in the toolkit of every researcher in the behavioral sciences. The purpose of this book is to make it possible for measurement specialists to solve practical testing problems through the use of item response theory irt. This graduatelevel textbook is a tutorial for item response theory that covers both the basics of item response theory and the use of r for preparing graphical presentation in writings about the theory. Lord devised models to categorize test questions based on dif. Item response theory irt has grown from its roots in postwar mental testing problems, through intensive use in educational measurements in the 1970s, 1980s, and 1990s, to become a mature statistical toolkit for modeling of multivariate discrete response data using subjectlevel latent variables. Item analysis is especially valuable in improving items which will be used again in later tests, but it can also be used to eliminate ambiguous or. Relevance and advantages of using the item response theory. In the second phase of the project, rti is to assign a common metric to knowledge item sets e. Advances in psychometrics have focused on measuring multiple dimensions of ability to provide more detailed feedback for students, teachers, and other stakeholders. Item response theory versus classical test theory uses of irt item banking short forms computerized adaptive tests. Reliability is seen as a characteristic of the test and of.
A necessary prerequisite to the operational use of item response theory irt in any testing program is the investigation of the feasibility of such an approach. Item response theory irt, is an approach to test development which. This document, which is a practical introduction to item response theory irt and rasch modeling, is composed of five parts. Chapter 8 the new psychometrics item response theory. Item response theory, reliability and standard error. Item response theory irt has become a popular methodological framework for modeling response data from assessments in education and health.
Lords book, applications of item response theory to practical testing problems, presented much of the current irt theory in language easily understood by many practitioners. This theory was developed and expanded for over 50 years and has contributed to the development of measurement scales of latent traits. Apr 01, 2016 purpose this study investigated the feasibility and potential validity of an item response theory irtbased computerized adaptive testing cat version of the macarthurbates communicative development inventory. While the basic concepts of item response theory were, and are, straightforward, the underlying mathematics was somewhat advanced compared to that of classical test theory. Item response theory irt is used in the design, analysis, scoring, and comparison of tests and similar instruments whose purpose is to measure unobservable characteristics of the respondents. Irt uses a statistical model to express the relationship between an individuals response to an item and the. Requirements for measurement measurement requires the concept of an underlying trait that can be expressed in terms of more or less test items are. In proceedings of the 50th acm technical symposium on. Item response theory psychology oxford bibliographies. Item response theory an overview sciencedirect topics.
Irts popularity is largely due to the fact that an irt model may be used to estimate parameters of test items and. It provides a powerful means to study individual responses to a variety of stimuli, and the methodology has been extended and developed to cover many different models of interaction. It is not the only modern test theory, but it is the most popular one and is currently an area of active research. Irt measures the specific characteristics of each item. This is a modern test theory as opposed to classical test theory. Moreover, the applications and uses of technology in language testing are discussed in a couple of chapters.
Itemresponse theory the unidimensionality assumption. An item response theorybased, computerized adaptive testing. Its a theory of measurement, more precisely a psychometric theory. It is widely used in education to calibrate and evaluate items in tests, questionnaires, and other instruments and to score subjects on their abilities, attitudes, or other latent traits. Item response theory in language testing ellis major. While now 50 years old assuming the birth is the classic lord and novick 1969 text it is still underutilized and remains a mystery to many practitioners. Item response theory aka irt is also sometimes called latent trait theory. Item response theory irt is also known as modern testing theory or latent trait theory. Applications of item response theory to practical testing. However, no manipulation of these axioms makes it a model of both item and test scores. The measurement models better known and used currently are mentioned, the classical test theory ctt, and item response theory irt, including the rasch model.
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