It is called latent trait theory attempting to predict observations from places on latent variable. Item response theory irt, also known as latent trait theory or modern mental test theory. 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. Item response theory an overview sciencedirect topics.
Novick on test theory, which was an expansion of his dissertation. The different options afforded to language testers are outlined and demonstrated with a working example taken from an authentic foreign language test. The focus of the present chapter is to introduce different options for undertaking item analysis, with particular focus on item response theory. In the second phase of the project, rti is to assign a common metric to knowledge item sets e. Reliability is seen as a characteristic of the test and of. Irt is the statistical basis for analyzing multiplechoice survey or test data for researchers, social scientists, and others who want to. Item response theory irt is concerned with accurate test scoring and development of test items.
Each specific irt model makes specific assumptions about the. Additionally, reliability and dependability as well as the scoring of performance tests are covered. Next, we consider how irt has been used in clinical research for. Item response theory psychology oxford bibliographies. Thus, the use of multidimensional item response theory in composite score creation may provide better composite estimates. Introduction to classical test theory ji zeng and adam wyse. Language testing professionals and teacher educators have articulated the need for a broad variety stakeholdersincluding classroom teachers to develop. 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. Applications of item response theory to practical testing. Birnbaums three parameter logistic item response theory 3pl irt model is. Classical test theory ctt, generalizability theory gtheory, item response theory irt, and differential item functioning dif. It is a theory of testing based on the relationship. Based upon items rather than test scores, the new approach was known as item response theory. Download citation item response theory in language testing language test tasks and items are particularly susceptive to factors that make responses by.
Applying item response theory in language test item bank. Language test tasks and items are particularly susceptive to factors that make responses by test candidates ambiguous. 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. 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. It is not the only modern test theory, but it is the most popular one and is currently an area of active research. In classical test theory, items on a scale measuring a single construct are generally considered to be equivalent to each other. Its a theory of measurement, more precisely a psychometric theory. Classical test theory ctt and item response theory irt classical test theory ctt and item response theory irt are testing item assessment approaches. Irt measures the specific characteristics of each item. 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 represents an important innovation in the field of psychometrics. 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.
Item response theory has become an essential component in the toolkit of every researcher in the behavioral sciences. Whereas classical test theory focuses on the test as a whole, item response theory shifts its focus to the individual items questions themselves. Comparisons between classical test theory and item response. An introductory 3day course introducing item response theory measurement models applied to psychological and educational data. This is a modern test theory as opposed to classical test theory. A simple guide to the item response theory irt and rasch. Item response theory irt, is an approach to test development which. Traditional testing procedures typically utilize unidimensional item response theory irt models to provide a single, continuous estimate of a students overall ability. This entry discusses some fundamental and theoretical aspects of irt and illustrates these with worked examples. 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.
Each specific irt model makes specific assumptions about the relationship between the test takers ability and his performances on a given item. Another branch of psychometric theory is the item response theory irt. Test dependent item response theory is essentially a nonlinear common factor model mcdonald, 1999, p. Irt was applied to two scales a positive and a negative affect. Moreover, the applications and uses of technology in language testing are discussed in a couple of chapters.
Item response theory, reliability and standard error. Item response theory irt is a set of statistical methods that are increasingly used for developing instruments in speech language pathology. Pdf applying item response theory in language test item. In proceedings of the 50th acm technical symposium on. Item characteristic curve in one to three parameter models iii. An application of item response theory to psychological. This theory was developed and expanded for over 50 years and has contributed to the development of measurement scales of latent traits. The item response theory irt also known as latent trait theory, is used for the development, evaluation and administration of standardized measurements. An application of item response theory to psychological test. Itemresponse theory the unidimensionality assumption. In its simplest form, item response theory posits that the probability of a random person j with ability. Combining item response theory and diagnostic classification. 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.
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. 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 part seven, various theories of language testing including classical test theory, generalizability theory, and item response theory are discussed in separate chapters. Relevance and advantages of using the item response theory. Apr 18, 2016 item response theory irt has become a popular methodological framework for modeling response data from assessments in education and health. Assuming a nonparametric family of item response theory models, a theorybased procedure for testing the hypothesis of unidimensionality of the latent space is proposed. 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. This paper marks the beginning of item response theory as a measurement theory.
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. Questionnaire development and cognitive testing using item. Applying item response theory in language test item bank building. An application of item response theory to language testing. Item response theory irt is arguably one of the most in. Item response theory evaluation of a languageindependent cs1 knowl edge assessment.
This document, which is a practical introduction to item response theory irt and rasch modeling, is composed of five parts. Item response theory, item response models, testing practices. 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. Pdf test theory, classical test theory researchgate. This paper aims to provide a didactic application of irt and to highlight some of these advantages for psychological test development. Item response theory in language testing researchgate. An item response theorybased, computerized adaptive testing. Item response theory in language testing ellis major. 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.
Lord devised models to categorize test questions based on dif. 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. The basics of item response theory using r statistics for. Item response theory was an upstart whose popular acceptance lagged in part because the. Classical test theory ctt and item response theory irt. Additionally, reliability and dependability as well as the scoring of performance tests are. Item response theory versus classical test theory uses of irt item banking short forms computerized adaptive tests. 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. 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. You will see the value in applying item response theory, possibly in your own organization.
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. 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. 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. This book explores the appropriateness of item response theory irt in language testing. In an issue of an early volume of applied measurement in education, eignor. 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. Results indi cate that although the language awareness test contains items with different response formats, only one latent trait is measured. However, no manipulation of these axioms makes it a model of both item and test scores. Irt may be regarded as roughly synonymous with latent trait theory. Demonstrating the difference between classical test theory. 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.
Understanding item analyses office of educational assessment. The material is organized to facilitate understanding. Chapter 8 the new psychometrics item response theory. It covered basic concepts, comparison to ctt methods, relative efficiency, optimal number of choices per item, flexilevel tests, multistage tests, tailored testing. 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. In many achievement testing situations it is useful or sometime required to. 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. Testing service ets, where he would work for 33 years. K r azavipour the routledge handbook of language testing. Item response theory and the assumption of unidimensionality for language tests grant henning, thom hudson, and jean turner language testing 1985 2.
Advances in psychometrics have focused on measuring multiple dimensions of ability to provide more detailed feedback for students, teachers, and other stakeholders. This paper attempts to familiarize the readers with such reliability camps. 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. Ctt and irt 5 scores, because we might apply ctt to one item tests and then it is a theory about item scores.
Item response theory statistical methods training course. Item response theory irt is arguably one of the most influential developments in the field of educational and psychological measurement. The final part covers the principles of language testing. Item response theory and computerized adaptive testing. 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. 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. 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 irt has become a popular methodological framework for modeling response data from assessments in education and health. 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. It is widely used in education to calibrate and evaluate items in tests, questionnaires, and other. 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. 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. Modeldata fit studies welcome to the ideals repository.
The penultimate part addresses test administration, as well as interlocutor and rater training. The role of item response theory in language test validation. Item selection using ctt and irt with unrepresentative samples. While irt is not new, its application in speech language. In connection to language testing, there are four such camps. Building an evaluation scale using item response theory acl. 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. Reliability in language testing linkedin slideshare.
Irt uses a statistical model to express the relationship between an individuals response to an item and the. This course introduces item response theory irt applied to both dichotomous twooutcome data and polytomous multiple outcome data. Questionnaire development and cognitive testing using item response theory irt. Psychometric theory offers two approaches in analyzing test data.
Item response theory in r using package ltm dimitris rizopoulos department of biostatistics, erasmus university medical center, the netherlands d. 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. Item information function and test information function iv. Validity of the three parameter item response theory model.
Item response theory and the assumption of unidimensionality. The topics, organization, and presentation are those used in a 4week seminar held each summer for the past several years. 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. Item response theory the unidimensionality assumption. 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. 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. Requirements for measurement measurement requires the concept of an underlying trait that can be expressed in terms of more or less test items are. 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. Irts popularity is largely due to the fact that an irt model may be used to estimate parameters of test items and. University of groningen applications of item response theory. 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. 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. 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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