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| 2. |
- Andersson, Björn, 1984-
(författare)
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Contributions to Kernel Equating
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The statistical practice of equating is needed when scores on different versions of the same standardized test are to be compared. This thesis constitutes four contributions to the observed-score equating framework kernel equating.Paper I introduces the open source R package kequate which enables the equating of observed scores using the kernel method of test equating in all common equating designs. The package is designed for ease of use and integrates well with other packages. The equating methods non-equivalent groups with covariates and item response theory observed-score kernel equating are currently not available in any other software package.In paper II an alternative bandwidth selection method for the kernel method of test equating is proposed. The new method is designed for usage with non-smooth data such as when using the observed data directly, without pre-smoothing. In previously used bandwidth selection methods, the variability from the bandwidth selection was disregarded when calculating the asymptotic standard errors. Here, the bandwidth selection is accounted for and updated asymptotic standard error derivations are provided.Item response theory observed-score kernel equating for the non-equivalent groups with anchor test design is introduced in paper III. Multivariate observed-score kernel equating functions are defined and their asymptotic covariance matrices are derived. An empirical example in the form of a standardized achievement test is used and the item response theory methods are compared to previously used log-linear methods.In paper IV, Wald tests for equating differences in item response theory observed-score kernel equating are conducted using the results from paper III. Simulations are performed to evaluate the empirical significance level and power under different settings, showing that the Wald test is more powerful than the Hommel multiple hypothesis testing method. Data from a psychometric licensure test and a standardized achievement test are used to exemplify the hypothesis testing procedure. The results show that using the Wald test can provide different conclusions to using the Hommel procedure.
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| 3. |
- Andersson, Björn, 1984-, et al.
(författare)
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Improving the Bandwidth Selection in Kernel Equating
- 2014
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Ingår i: Journal of educational measurement. - : Blackwell Publishing. - 0022-0655 .- 1745-3984. ; 51:3, s. 223-238
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the current bandwidth selection methods in kernel equating and propose a method based on Silverman's rule of thumb for selecting the bandwidth parameters. In kernel equating, the bandwidth parameters have previously been obtained by minimizing a penalty function. This minimization process has been criticized by practitioners for being too complex and that it does not offer sufficient smoothing in certain cases. In addition, the bandwidth parameters have been treated as constants in the derivation of the standard error of equating even when they were selected by considering the observed data. Here, the bandwidth selection is simplified, and modified standard errors of equating (SEEs) that reflect the bandwidth selection method are derived. The method is illustrated with real data examples and simulated data.
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| 4. |
- Andersson, Carolyn J., et al.
(författare)
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Stories of successful careers in psychometrics and what we can learn from them
- 2020
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Ingår i: Quantitative psychology. - New York : Springer. - 9783030434687 - 9783030434694 ; , s. 1-17
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Bokkapitel (refereegranskat)abstract
- This paper was inspired by the presentations and discussions from the panel "Successful Careers in Academia and Industry and What We Can Learn from Them”" that took place at the IMPS meeting in 2019. In this paper, we discuss what makes a career successful in academia and industry and we provide examples from the past to the present. We include education and career paths as well as highlights of achievements as researchers and teachers. The paper provides a brief historical context for the representation of women in psychometrics and an insight into strategies for success for publishing, for grant applications and promotion. The authors outline the importance of interdisciplinary work, the inclusive citation approaches, and visibility of research in academia and industry. The personal stories provide a platform for considering the needs for a supportive work environment for women and for work-life balance. The outcome of these discussions and reflections of the panel members are included in the paper.
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| 5. |
- González, Jorge, et al.
(författare)
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A note on the Poisson's binomial distribution in Item Response Theory
- 2016
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Ingår i: Applied psychological measurement. - : SAGE Publications. - 0146-6216 .- 1552-3497. ; 40:2, s. 302-310
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Tidskriftsartikel (refereegranskat)abstract
- The Poisson's binomial (PB) is the probability distribution of the number of successes in independent but not necessarily identically distributed binary trials. The independent non-identically distributed case emerges naturally in the field of item response theory, where answers to a set of binary items are conditionally independent given the level of ability, but with different probabilities of success. In many applications, the number of successes represents the score obtained by individuals, and the compound binomial (CB) distribution has been used to obtain score probabilities. It is shown here that the PB and the CB distributions lead to equivalent probabilities. Furthermore, one of the proposed algorithms to calculate the PB probabilities coincides exactly with the well-known Lord and Wingersky (LW) algorithm for CBs. Surprisingly, we could not find any reference in the psychometric literature pointing to this equivalence. In a simulation study, different methods to calculate the PB distribution are compared with the LW algorithm. Providing an exact alternative to the traditional LWapproximation for obtaining score distributions is a contribution to the field.
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| 6. |
- Wiberg, Marie, et al.
(författare)
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Examining the Impact of Covariates on Anchor Tests to Ascertain Quality Over Time in a College Admissions Test
- 2017
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Ingår i: International Journal of Testing. - : Taylor & Francis. - 1530-5058 .- 1532-7574. ; 17:2, s. 105-126
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Tidskriftsartikel (refereegranskat)abstract
- We propose a comprehensive procedure for the implementation of a quality control process of anchor tests for a college admissions test with multiple consecutive administrations. We propose to examine the anchor tests and their items in connection with covariates to investigate if there was any unusual behavior in the anchor test results over time and if the test results differed for different groups of test takers. Descriptive statistics, ANOVA, and linear mixed effect models were used to examine the impact of covariates on the anchor test over time. Descriptive statistics and logistic regression were used to examine the quality of each anchor item over time. It is concluded that examining the impact of the test takers' covariates at different administrations can help in the process of providing fair tests for all test takers. The results are discussed with recommendations how it can be used in other large testing programs.
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| 7. |
- Wiberg, Marie, 1976-, et al.
(författare)
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Local Observed-Score Kernel Equating
- 2014
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Ingår i: Journal of educational measurement. - : Wiley. - 0022-0655 .- 1745-3984. ; 51:1, s. 57-74
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Tidskriftsartikel (refereegranskat)abstract
- Three local observed-score kernel equating methods that integrate methods from the local equating and kernel equating frameworks are proposed. The new methods were compared with their earlier counterparts with respect to such measures as biasas defined by Lord's criterion of equityand percent relative error. The local kernel item response theory observed-score equating method, which can be used for any of the common equating designs, had a small amount of bias, a low percent relative error, and a relatively low kernel standard error of equating, even when the accuracy of the test was reduced. The local kernel equating methods for the nonequivalent groups with anchor test generally had low bias and were quite stable against changes in the accuracy or length of the anchor test. Although all proposed methods showed small percent relative errors, the local kernel equating methods for the nonequivalent groups with anchor test design had somewhat larger standard error of equating than their kernel method counterparts.
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