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1.
A computerized adaptive testing (CAT) algorithm that has the potential to increase the homogeneity of CAT's item-exposure rates without significantly sacrificing the precision of ability estimates was proposed and assessed in the shadow-test ( van der Linden & Reese, 1998 ) CAT context. This CAT algorithm was formed by a combination of maximizing or minimizing varied target functions while assembling shadow tests. There were four target functions to be separately used in the first, second, third, and fourth quarter test of CAT. The elements to be used in the four functions were associated with (a) a random number assigned to each item, (b) the absolute difference between an examinee's current ability estimate and an item difficulty, (c) the absolute difference between an examinee's current ability estimate and an optimum item difficulty, and (d) item information. The results indicated that this combined CAT fully utilized all the items in the pool, reduced the maximum exposure rates, and achieved more homogeneous exposure rates. Moreover, its precision in recovering ability estimates was similar to that of the maximum item-information method. The combined CAT method resulted in the best overall results compared with the other individual CAT item-selection methods. The findings from the combined CAT are encouraging. Future uses are discussed.  相似文献   

2.
Preventing items in adaptive testing from being over- or underexposed is one of the main problems in computerized adaptive testing. Though the problem of overexposed items can be solved using a probabilistic item-exposure control method, such methods are unable to deal with the problem of underexposed items. Using a system of rotating item pools, on the other hand, is a method that potentially solves both problems. In this method, a master pool is divided into (possibly overlapping) smaller item pools, which are required to have similar distributions of content and statistical attributes. These pools are rotated among the testing sites to realize desirable exposure rates for the items. A test assembly model, motivated by Gulliksen's matched random subtests method, was explored to help solve the problem of dividing a master pool into a set of smaller pools. Different methods to solve the model are proposed. An item pool from the Law School Admission Test was used to evaluate the performances of computerized adaptive tests from systems of rotating item pools constructed using these methods.  相似文献   

3.
In test assembly, a fundamental difference exists between algorithms that select a test sequentially or simultaneously. Sequential assembly allows us to optimize an objective function at the examinee's ability estimate, such as the test information function in computerized adaptive testing. But it leads to the non-trivial problem of how to realize a set of content constraints on the test—a problem more naturally solved by a simultaneous item-selection method. Three main item-selection methods in adaptive testing offer solutions to this dilemma. The spiraling method moves item selection across categories of items in the pool proportionally to the numbers needed from them. Item selection by the weighted-deviations method (WDM) and the shadow test approach (STA) is based on projections of the future consequences of selecting an item. These two methods differ in that the former calculates a projection of a weighted sum of the attributes of the eventual test and the latter a projection of the test itself. The pros and cons of these methods are analyzed. An empirical comparison between the WDM and STA was conducted for an adaptive version of the Law School Admission Test (LSAT), which showed equally good item-exposure rates but violations of some of the constraints and larger bias and inaccuracy of the ability estimator for the WDM.  相似文献   

4.
Successful administration of computerized adaptive testing (CAT) programs in educational settings requires that test security and item exposure control issues be taken seriously. Developing an item selection algorithm that strikes the right balance between test precision and level of item pool utilization is the key to successful implementation and long‐term quality control of CAT. This study proposed a new item selection method using the “efficiency balanced information” criterion to address issues with the maximum Fisher information method and stratification methods. According to the simulation results, the new efficiency balanced information method had desirable advantages over the other studied item selection methods in terms of improving the optimality of CAT assembly and utilizing items with low a‐values while eliminating the need for item pool stratification.  相似文献   

5.
This study compared the properties of five methods of item exposure control within the purview of estimating examinees' abilities in a computerized adaptive testing (CAT) context. Each exposure control algorithm was incorporated into the item selection procedure and the adaptive testing progressed based on the CAT design established for this study. The merits and shortcomings of these strategies were considered under different item pool sizes and different desired maximum exposure rates and were evaluated in light of the observed maximum exposure rates, the test overlap rates, and the conditional standard errors of measurement. Each method had its advantages and disadvantages, but no one possessed all of the desired characteristics. There was a clear and logical trade-off between item exposure control and measurement precision. The Stocking and Lewis conditional multinomial procedure and, to a slightly lesser extent, the Davey and Parshall method seemed to be the most promising considering all of the factors that this study addressed.  相似文献   

6.
APPLICATION OF COMPUTERIZED ADAPTIVE TESTING TO EDUCATIONAL PROBLEMS   总被引:1,自引:0,他引:1  
Three applications of computerized adaptive testing (CAT) to help solve problems encountered in educational settings are described and discussed. Each of these applications makes use of item response theory to select test questions from an item pool to estimate a student's achievement level and its precision. These estimates may then be used in conjunction with certain testing strategies to facilitate certain educational decisions. The three applications considered are (a) adaptive mastery testing for determining whether or not a student has mastered a particular content area, (b) adaptive grading for assigning grades to students, and (c) adaptive self-referenced testing for estimating change in a student's achievement level. Differences between currently used classroom procedures and these CAT procedures are discussed. For the adaptive mastery testing procedure, evidence from a series of studies comparing conventional and adaptive testing procedures is presented showing that the adaptive procedure results in more accurate mastery classifications than do conventional mastery tests, while using fewer test questions.  相似文献   

7.
The intent of this research was to find an item selection procedure in the multidimensional computer adaptive testing (CAT) framework that yielded higher precision for both the domain and composite abilities, had a higher usage of the item pool, and controlled the exposure rate. Five multidimensional CAT item selection procedures (minimum angle; volume; minimum error variance of the linear combination; minimum error variance of the composite score with optimized weight; and Kullback‐Leibler information) were studied and compared with two methods for item exposure control (the Sympson‐Hetter procedure and the fixed‐rate procedure, the latter simply refers to putting a limit on the item exposure rate) using simulated data. The maximum priority index method was used for the content constraints. Results showed that the Sympson‐Hetter procedure yielded better precision than the fixed‐rate procedure but had much lower item pool usage and took more time. The five item selection procedures performed similarly under Sympson‐Hetter. For the fixed‐rate procedure, there was a trade‐off between the precision of the ability estimates and the item pool usage: the five procedures had different patterns. It was found that (1) Kullback‐Leibler had better precision but lower item pool usage; (2) minimum angle and volume had balanced precision and item pool usage; and (3) the two methods minimizing the error variance had the best item pool usage and comparable overall score recovery but less precision for certain domains. The priority index for content constraints and item exposure was implemented successfully.  相似文献   

8.
This paper proposes two new item selection methods for cognitive diagnostic computerized adaptive testing: the restrictive progressive method and the restrictive threshold method. They are built upon the posterior weighted Kullback‐Leibler (KL) information index but include additional stochastic components either in the item selection index or in the item selection procedure. Simulation studies show that both methods are successful at simultaneously suppressing overexposed items and increasing the usage of underexposed items. Compared to item selection based upon (1) pure KL information and (2) the Sympson‐Hetter method, the two new methods strike a better balance between item exposure control and measurement accuracy. The two new methods are also compared with Barrada et al.'s (2008) progressive method and proportional method.  相似文献   

9.
Computerized adaptive testing (CAT) has gained deserved popularity in the administration of educational and professional assessments, but continues to face test security challenges. To ensure sustained quality assurance and testing integrity, it is imperative to establish and maintain multiple stable item pools that are consistent in terms of psychometric characteristics and content specifications. This study introduces the Honeycomb Pool Assembly (HPA) framework, an innovative solution for the construction of multiple parallel item pools for CAT that maximizes item utilization in the item bank. The HPA framework comprises two stages—cell assembly and pool assembly—and uses a mixed integer programming modeling approach. An empirical study demonstrated HPA's effectiveness in creating a large number of parallel pools using a real-world high-stakes CAT assessment item bank. The HPA framework offers several advantages, including (a) simultaneous creation of multiple parallel pools, (b) simplification of item pool maintenance, and (c) flexibility in establishing statistical and operational constraints. Moreover, it can help testing organizations efficiently manage and monitor the health of their item banks. Thus, the HPA framework is expected to be a valuable tool for testing professionals and organizations to address test security challenges and maintain the integrity of high-stakes CAT assessments.  相似文献   

10.
The use of computerized adaptive testing algorithms for ranking items (e.g., college preferences, career choices) involves two major challenges: unacceptably high computation times (selecting from a large item pool with many dimensions) and biased results (enhanced preferences or intensified examinee responses because of repeated statements across items). To address these issues, we introduce subpool partition strategies for item selection and within-person statement exposure control procedures. Simulations showed that the multinomial method reduces computation time while maintaining measurement precision. Both the freeze and revised Sympson-Hetter online (RSHO) methods controlled the statement exposure rate; RSHO sacrificed some measurement precision but increased pool use. Furthermore, preventing a statement's repetition on consecutive items neither hindered the effectiveness of the freeze or RSHO method nor reduced measurement precision.  相似文献   

11.
近年来由于信息技术的进步,采用计算机自适应测试进行评价得到迅速的发展;此外,移动技术的可用性也为评价提供了新的途径。文章设计并开发了面向多类终端的自适应测试系统,在项目选择过程中充分考虑了已有算法所存在的部分项目曝光率高、题库利用率低、内容平衡等问题,重新设计了项目选择引擎。通过该系统可以为形成性评估、总结性评估和自我评估提供支持。  相似文献   

12.
13.
Educational Testing Service A multiple-choice test item is identified as flawed if it has no single best answer. In spite of extensive quality control procedures, the administration of flawed items to test takers is inevitable. A limited set of common strategies for dealing with flawed items in conventional testing, grounded in the principle of fairness to examinees, is reexamined in the context of adaptive testing. An additional strategy, available for adaptive testing, of retesting from a pool cleansed of flawed items, is compared to the existing strategies. Retesting was found to be no practical improvement over current strategies.  相似文献   

14.
Permitting item review is to the benefit of the examinees who typically increase their test scores with item review. However, testing companies do not prefer item review since it does not follow the logic on which adaptive tests are based, and since it is prone to cheating strategies. Consequently, item review is not permitted in many adaptive tests. This study attempts to provide a solution that would allow examinees to revise their answers, without jeopardizing the quality and efficiency of the test. The purpose of this study is to test the efficiency of a “rearrangement procedure” that rearranges and skips certain items in order to better estimate the examinees' abilities, without allowing them to cheat on the test. This was examined through a simulation study. The results show that the rearrangement procedure is effective in reducing the standard error of the Bayesian ability estimates and in increasing the reliability of the same estimates.  相似文献   

15.
In computerized adaptive testing (CAT), ensuring the security of test items is a crucial practical consideration. A common approach to reducing item theft is to define maximum item exposure rates, i.e., to limit the proportion of examinees to whom a given item can be administered. Numerous methods for controlling exposure rates have been proposed for tests employing the unidimensional 3-PL model. The present article explores the issues associated with controlling exposure rates when a multidimensional item response theory (MIRT) model is utilized and exposure rates must be controlled conditional upon ability. This situation is complicated by the exponentially increasing number of possible ability values in multiple dimensions. The article introduces a new procedure, called the generalized Stocking-Lewis method, that controls the exposure rate for students of comparable ability as well as with respect to the overall population. A realistic simulation set compares the new method with three other approaches: Kullback-Leibler information with no exposure control, Kullback-Leibler information with unconditional Sympson-Hetter exposure control, and random item selection.  相似文献   

16.
本文结合专家经验确定法和项目反应理论,设计出一种简明、实用的计算机自适应考试系统的试题难度确定方法,同时重点分析计算机自适应考试系统的测试起点、终点选择,选题策略和能力值估计方法。最后列举了一个自适应测试的步骤实例。本系统能够根据不同能力被试者随机选择试题项目,减少了测试长度,与传统在线考试系统相比提高了考试效率。  相似文献   

17.
The development of cognitive diagnostic‐computerized adaptive testing (CD‐CAT) has provided a new perspective for gaining information about examinees' mastery on a set of cognitive attributes. This study proposes a new item selection method within the framework of dual‐objective CD‐CAT that simultaneously addresses examinees' attribute mastery status and overall test performance. The new procedure is based on the Jensen‐Shannon (JS) divergence, a symmetrized version of the Kullback‐Leibler divergence. We show that the JS divergence resolves the noncomparability problem of the dual information index and has close relationships with Shannon entropy, mutual information, and Fisher information. The performance of the JS divergence is evaluated in simulation studies in comparison with the methods available in the literature. Results suggest that the JS divergence achieves parallel or more precise recovery of latent trait variables compared to the existing methods and maintains practical advantages in computation and item pool usage.  相似文献   

18.
The purpose of this article is to present an analytical derivation for the mathematical form of an average between-test overlap index as a function of the item exposure index, for fixed-length computerized adaptive tests (CATs). This algebraic relationship is used to investigate the simultaneous control of item exposure at both the item and test levels. The results indicate that, in fixed-length CATs, control of the average between-test overlap is achieved via the mean and variance of the item exposure rates of the items that constitute the CAT item pool. The mean of the item exposure rates is easily manipulated. Control over the variance of the item exposure rates can be achieved via the maximum item exposure rate (rmax). Therefore, item exposure control methods which implement a specification of rmax (e.g., Sympson & Hetter, 1985) provide the most direct control at both the item and test levels.  相似文献   

19.
In cognitive diagnostic models (CDMs), a set of fine-grained attributes is required to characterize complex problem solving and provide detailed diagnostic information about an examinee. However, it is challenging to ensure reliable estimation and control computational complexity when The test aims to identify the examinee's attribute profile in a large-scale map of attributes. To address this problem, this study proposes a cognitive diagnostic multistage testing by partitioning hierarchically structured attributes (CD-MST-PH) as a multistage testing for CDM. In CD-MST-PH, multiple testlets can be constructed based on separate attribute groups before testing occurs, which retains the advantages of multistage testing over fully adaptive testing or the on-the-fly approach. Moreover, testlets are offered sequentially and adaptively, thus improving test accuracy and efficiency. An item information measure is proposed to compute the discrimination power of an item for each attribute, and a module assembly method is presented to construct modules anchored at each separate attribute group. Several module selection indices for CD-MST-PH are also proposed by modifying the item selection indices used in cognitive diagnostic computerized adaptive testing. The results of simulation study show that CD-MST-PH can improve test accuracy and efficiency relative to the conventional test without adaptive stages.  相似文献   

20.
《教育实用测度》2013,26(3):241-261
This simulation study compared two procedures to enable an adaptive test to select items in correspondence with a content blueprint. Trait level estimates obtained from testlet-based and constrained adaptive tests administered to 10,000 simulated examinees under two trait distributions and three item pool sizes were compared to the trait level estimates obtained from traditional adaptive tests in terms of mean absolute error, bias, and information. Results indicate that using constrained adaptive testing requires an increase of 5% to 11% in test length over the traditional adaptive test to reach the same error level and, using testlets requires an increase of 43% to 104% in test length over the traditional adaptive test. Given these results, the use of constrained computerized adaptive testing is recommended for situations in which an adaptive test must adhere to particular content specifications.  相似文献   

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