This simulation study examines itemlevel differential item functioning dif in the context of international largescale assessment ilsa using a generalized logistic regression approach. Differential item functioning of the geriatric depression scale in an asian population. Relatively fewer studies examined an item level approach to measurement equivalence, particularly in settings where a large number of groups is included. Differential item functioning dif is a statistical characteristic of an item that shows the extent to. Differential item functioning dif is present for a test item when respondents from two subpopulations with the same trait level have different probability of answering the item correctly. Logistic regression provides a flexible framework for detecting various types of differential item functioning dif.
Differential item functioning analysis with ordinal logistic regression techniques difdetect and difwithpar paul k. Empirical studies on differential item functioning 36 research in dikereniial liem fmciioning 36 methods of detecting differential item functioning 3 9 meinojs ihai examine dikerencr, in item d. Software for analyzing differential item functioning using the mantel haenszel and standardization procedures. Computer piracy is the unauthorized use of ed software. Dorans, evaluating hypotheses about differential item functioning. Differential item functioning in attitude assessment sciencedirect. May 10, 2016 there is a highly divisive and costly practice that software companies have inflicted on their customers for nearly a decade. Digital piracy is a growing concern among content creators of all stripes.
An introduction to differential item functioning analysis eric. An overview of differential item functioning in multistage. Mar 01, 2011 a handbook on the theory and methods of differential item functioning dif. The value of the studied item in the matchin criterion in. For each method, a number of the relevant software are also introduced. Oct 18, 2016 digital piracy is a growing concern among content creators of all stripes. Copying music for a friend, downloading a commercially licensed program from the internet without purchasing it and even using software in a way that violates the end user license agreement. Music piracy is also quite prevalent with more than 27 billion media files transferred each year through p2p programs house of representatives 2004. If the factor bringing about such a difference is not part of the construct of focus in the test, then the test would be biased. There is a highly divisive and costly practice that software companies have inflicted on their customers for nearly a decade. One of the key techniques researchers use in measurement is to investigate differential item functioning dif. This article provides a brief primer overview of differential item functioning dif analysis. Assessment developers design and construct questionnaires or tests including sets of items that measure, for example, cognition, personality traits, or political views.
Paper 29002015 multiple ways to detect differential item. Overuse of computer software licenses, also known as software piracy, occurs when your organization installs andor uses more copies of. Differential item functioning dif is an important issue of interest in psychometrics. Table 30 supports the investigation of item bias, differential item functioning dif, i.
The mh dif method was conducted using the differential item functioning analysis system difas computer program penfield, 2005. Differential item functioning dif refers to group differences in performance on a test item that cannot be explained by group differences in the construct targeted. Sep 01, 2017 this is the webpage for the handbook on differential item functioning. Gender and ethnicitybased differential item functioning on. Differential item functioning analysis with ordinal logistic. Naep analysis and scaling differential item functioning.
Software piracy is a serious issue that has been affecting software companies for decades. The investigation of differential item functioning in adaptive tests. Directorate of human resources research and evaluation, department of national defense. Differential item functioning dif is when a test item favors or hinders a characteristic exhibited by group members of a testtaking population. As demonstration, a dataset from a 40item math test in a statewide testing program is analyzed by two widely. Software piracy is considered direct infringement when it denies holders due compensation for use of their creative works. Differential item functioning true score computerize adaptive test differential item functioning analysis item response function these keywords were added by machine and not by the authors. Occurrences and sources of differential item functioning. Dif analyses are statistical procedures used to determine to what extent the content of an item affects the item endorsement of subgroups of testtakers. Readers are provided with guidance on how to interpret numerous critical winsteps tables which help one identify items exhibiting dif.
A new method for detecting differential item functioning in. Relatively fewer studies examined an itemlevel approach to measurement equivalence, particularly in settings where a large number of groups is included. Differential item functioning dif refers to a difference in item. Differential item functioning dif, or item bias, occurs when individuals in a focal group respond differently to a test item than do individuals in a reference group even when comparisons are restricted to individuals with similar overall skill levels on the trait in question.
Detecting differential item functioning using generalized. The purpose of the present analysis is to use differential item functioning dif to identify differences in the performance of native and immigrant students in pisa 2009 that can be directly related to their responses to particular items. Differential item functioning dif is not often seen in the literature on attitude. New programs for differential item function dif and for. Mitigating your organizations exposure to software piracy. The study of differential item functioning can also be used to ensure that testing instruments hold over time the second aim of our study. Software for analyzing differential item functioning. The rankbased method together with the computer software. Pmc free article broekman bfp, nyunt sz, niti m, jin az, ko sm, kumar r, fones csl, ng tp. Item response theory irt methodologies were employed in order to examine the myersbriggs type indicator mbti for differential item functioning dif on the basis of crossed gender and ethnicity variables. Under law, software piracy occurs when protected software is copied, distributed, modified or sold. Pdf on sep 1, 2011, andres gonzalez and others published easydif. We analyzed 95 cognitive reading items, administered to students in 29 european countries.
Software piracy is the duplication, distribution or use of software without permission from the owner. The assessment of differential item functioning in comput. Pdf an introduction to differential item functioning researchgate. Coping with a computeradministered test of academic skills. A consequence of having a dif item is that the same true trait levels for examinees from different subpopulations could indicate different total test. White males were the reference group, and the focal groups were. Thanks to kit baum, 4 new programs for detecting differential item function dif and for interfacing with parscale are downloadable from ssc. A new method for detecting differential item functioning. Burton, the effect of item screening on test scores and test characteristics. Differential item functioning between ethnic groups in the epidemiological assessment of depression.
Occurrences and sources of differential item functioning dif. Measuring differential item and test functioning across. This article provides an applied example using sibtest statistical software to detect dif in u. An explanatory differential item functioning dif model. According to robert hollyman, bsa president and chief executive officer, software piracy robs the global economy of hundreds of thousands of jobs and billions of dollars in wages and tax revenues. A computer program for irt differential item functioning analysis. A general framework and an r package for the detection of. A variety of statistical procedures have been developed to assess dif in tests of dichotomous hills, 1989. Differential item functioning analysis with ordinal. As is commonly done, the total score was used as the matching. In this chapter, we give examples to help define what dif is and why it is important to understand. But we expect that a copy would be very similar to the genuine. The rows in each group refer to the levels from lower to higher, with the fourth row indicating the sum of each ability level. This process is experimental and the keywords may be updated as the learning algorithm improves.
South african companies nailed for using pirated software. Software piracy is the stealing of legally protected software. Studies of changing piracy rates indicate several benefits from decreasing the prevalence of piracy. This simulation study examines item level differential item functioning dif in the context of international largescale assessment ilsa using a generalized logistic regression approach. Differential item functioning dif has been widely used in healthcare, business management, and educational measurement. The sequential guide to securing yourself against software. The administration of invalsi anchor test is aiming at developing an instrument to maintain constant the difficulty level of test. Lewis, a note on the value of including the studied item in the test score when analyzing test items for dif. Given the situation of software piracy in campus since it is a small community yet has quite big of potential software piracy practice. The diffreethendif strategy for the assessment of differential. New programs for differential item function dif and. Previous efforts extended the framework by using item response theory irt based trait scores, and by employing an iterative process using groupspecific item parameters to account for dif in the trait scores, analogous to purification approaches used in other. Software piracy on a grand scale, in which software and its packaging are illegally duplicated often by organized crime ringsthen redistributed as alleged legal product. A biased item deviates from the item response theory irt models used in naep, because the probability of doing well on the item depends not only on what the examinee knows and can do and on the item as reflected in the item parameters, but also on a characteristic of the item that is unrelated to the construct being measured.
Differential item functioning, validity, fairness, bias. In brief, differential item functioning dif occurs when groups such as defined by gender, ethnicity, age, or education have different probabilities of endorsing a given item on a multiitem scale after controlling for overall scale scores. Software piracy claims can ruin your business and reward. Gibbons, phd, lance jolley, ms, and gerald van belle, phd introduction. Some of these procedures, such as the mantelhaenszel. Consequences of software piracy the losses suffered as a result of software piracy directly affect the profitability of the software industry. Current issues 951 people who answered the item correctly at the ability level m, and the proportion of people who answered the item correctly at the ability level m, respectively. Oct 30, 2012 software piracy is the stealing of legally protected software. This is the webpage for the handbook on differential item functioning. Average item scores for subgroups having the same overall score on the test are compared to determine whether the item is measuring in essentially the. We present an ordinal logistic regression model for identi. Recommendations for conducting differential item functioning. Average item scores for subgroups having the same overall score on the test are compared to determine whether the item is measuring in essentially the same way for all subgroups.
April 2010 the value of the studied item in the matching criterion in differential item functioning dif analysis xuan tan, bihua xiang, neil j. A computer program for detecting uniform and nonuniform differential item. Dif analysis investigates a differential characteristic of a test item between subpopulations of examinees and is useful in detecting possibly biased items toward a particular subpopulation. Dif detection is a first step in assessing bias in test items. Evaluates test items for differential item functioning dif. This practice brings with it significant emotional duress, time. Differential item functioning columbia university mailman. Software for analyzing differential item functioning using the mantelhaenszel and. Because of the money lost to pirates, publishers have fewer resources to devote to research and development of new products, have less revenue to justify lowering software prices and are forced to pass. The sequential guide to securing yourself against software piracy. Some of these procedures, such as the mantelhaenszel chi. A handbook on the theory and methods of differential item functioning dif. Apr 17, 2006 thanks to kit baum, 4 new programs for detecting differential item function dif and for interfacing with parscale are downloadable from ssc. Gender and ethnicitybased differential item functioning.
Differential item functioning dif is a way to make sure that a test does not favor one group of test takers over the others. Diffree and b assess the other items for dif differential item functioning. Logistic regression modeling as a unitary framework for binary and likerttype ordinal item scores. Differential item functioning dif is a statistical characteristic of an item that shows the extent to which the item might be measuring different abilities for members of separate subgroups.
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