a‐Stratified CAT design with content blocking

Content balancing is often required in the development and implementation of computerized adaptive tests (CATs). In the current study, we propose a modified a‐stratified method, the a‐stratified method with content blocking. As a further refinement of a‐stratified CAT designs, the new method incorporates content specifications into item pool stratification. Simulation studies were conducted to compare the new method with three previous item selection methods: the a‐stratified method; the a‐stratified with b‐blocking method; and the maximum Fisher information method with Sympson‐Hetter exposure control. The results indicated that the refined a‐stratified design performed well in reducing item overexposure rates, balancing item usage within the pool, and maintaining measurement precision, in a situation where all four procedures were forced to balance content.     

Combining computer adaptive testing technology with cognitively diagnostic assessment

A major advantage of computerized adaptive testing (CAT) is that it allows the test to home in on an examinee's ability level in an interactive manner. The aim of the new area of cognitive diagnosis is to provide information about specific content areas in which an examinee needs help. The goal of this study was to combine the benefit of specific feedback from cognitively diagnostic assessment with the advantages of CAT. In this study, three approaches to combining these were investigated: (1) item selection based on the traditional ability level estimate (theta), (2) item selection based on the attribute mastery feedback provided by cognitively diagnostic assessment (alpha), and (3) item selection based on both the traditional ability level estimate (theta) and the attribute mastery feedback provided by cognitively diagnostic assessment (alpha). The results from these three approaches were compared for theta estimation accuracy, attribute mastery estimation accuracy, and item exposure control. The theta- and alpha-based condition outperformed the alpha-based condition regarding theta estimation, attribute mastery pattern estimation, and item exposure control. Both the theta-based condition and the theta- and alpha-based condition performed similarly with regard to theta estimation, attribute mastery estimation, and item exposure control, but the theta- and alpha-based condition has an additional advantage in that it uses the shadow test method, which allows the administrator to incorporate additional constraints in the item selection process, such as content balancing, item type constraints, and so forth, and also to select items on the basis of both the current theta and alpha estimates, which can be built on top of existing 3PL testing programs.     

Less precise motor control leads to increased agonist-antagonist muscle activation during stick balancing

Human motor control has constraints in terms of its responsiveness, which limit its ability to successfully perform tasks. In a previous study, it was shown that the ability to balance an upright stick became progressively more challenging as the natural frequency (angular velocity without control) of the stick increased. Furthermore, forearm and trunk agonist and antagonist muscle activation increased as the natural frequency of the stick increased, providing evidence that the central nervous system produces agonist-antagonist muscle activation to match task dynamics. In the present study, visual feedback of the stick position was influenced by changing where subject focused on the stick during stick balancing. It was hypothesized that a lower focal height would degrade motor control (more uncertainty in tracking stick position), thus making balancing more challenging. The probability of successfully balancing the stick at four different focal heights was determined along with the average angular velocity of the stick. Electromyographic signals from forearm and trunk muscles were also recorded. As expected, the probability of successfully balancing the stick decreased and the average angular velocity of the stick increased as subjects focused lower on the stick. In addition, changes in the level of agonist and antagonist muscle activation in the forearm and trunk was linearly related to changes in the angular velocity of the stick during balancing. One possible explanation for this is that the central nervous system increases muscle activation to account for less precise motor control, possibly to improve the responsiveness of human motor control.     

Look-ahead content balancing method in variable-length computerized classification testing

Content balancing is one of the most important issues in computerized classification testing. To adapt to variable-length forms, special treatments are needed to successfully control content constraints without knowledge of test length during the test. To this end, we propose the notions of ‘look-ahead’ and ‘step size’ to adaptively control content constraints in each item selection step. The step size gives a prediction of the number of items to be selected at the current stage, that is, how far we will look ahead. Two look-ahead content balancing (LA-CB) methods, one with a constant step size and another with an adaptive step size, are proposed as feasible solutions to balancing content areas in variable-length computerized classification testing. The proposed LA-CB methods are compared with conventional item selection methods in variable-length tests and are examined with different classification methods. Simulation results show that, integrated with heuristic item selection methods, the proposed LA-CB methods result in fewer constraint violations and can maintain higher classification accuracy. In addition, the LA-CB method with an adaptive step size outperforms that with a constant step size in content management. Furthermore, the LA-CB methods generate higher test efficiency while using the sequential probability ratio test classification method.     

Controlling item exposure and test overlap on the fly in computerized adaptive testing

This paper proposes an on‐line version of the Sympson and Hetter procedure with test overlap control (SHT) that can provide item exposure control at both the item and test levels on the fly without iterative simulations. The on‐line procedure is similar to the SHT procedure in that exposure parameters are used for simultaneous control of item exposure rates and test overlap rate. The exposure parameters for the on‐line procedure, however, are updated sequentially on the fly, rather than through iterative simulations conducted prior to operational computerized adaptive tests (CATs). Unlike the SHT procedure, the on‐line version can control item exposure rate and test overlap rate without time‐consuming iterative simulations even when item pools or examinee populations have been changed. Moreover, the on‐line procedure was found to perform better than the SHT procedure in controlling item exposure and test overlap for examinees who take tests earlier. Compared with two other on‐line alternatives, this proposed on‐line method provided the best all‐around test security control. Thus, it would be an efficient procedure for controlling item exposure and test overlap in CATs.     

Predicting item exposure parameters in computerized adaptive testing

The purpose of this study is to find a formula that describes the relationship between item exposure parameters and item parameters in computerized adaptive tests by using genetic programming (GP) – a biologically inspired artificial intelligence technique. Based on the formula, item exposure parameters for new parallel item pools can be predicted without conducting additional iterative simulations. Results show that an interesting formula between item exposure parameters and item parameters in a pool can be found by using GP. The item exposure parameters predicted based on the found formula were close to those observed from the Sympson and Hetter (1985) procedure and performed well in controlling item exposure rates. Similar results were observed for the Stocking and Lewis (1998) multinomial model for item selection and the Sympson and Hetter procedure with content balancing. The proposed GP approach has provided a knowledge‐based solution for finding item exposure parameters.     

Intrahemispheric response competition between vocal and unimanual performances in normam adult human males.

Subjects balanced a dowel rod vertically on the left and right index finger singly and while simultaneously repeating phrases. With right-handed subjects who had no left-handed relatives, concurrent verbalization shortened right- but not left-handed balancing. Increased phonetic difficulty of the phrases produced an increased decrement on right-handed balancing, but left-handed balancing was unchanged; it also produced more verbalization errors on trials with the right hand, but not with the left. Concurrent verbalization shortened balancing duration with both hands of left-handers. Right-handers with left-handed relatives produced variable results. Concurrent humming also selectively interfered with right-handed balancing. It was concluded that the results conform to an interpretation based on intrahemispheric interference between incompatible, simultaneously produced sets of responses.     

认知诊断CAT中项目曝光控制方法的比较

项目曝光率关系到题库建设和测验安全,是计算机化自适应测验(Computerized Adaptive Testing, CAT)需要考虑的重要问题。在认知诊断 CAT 情形下,首先基于传统 CAT 中 a-分层方法的思想提出按项目信息量对题库分层的分层多阶段(Stratified Multistage, SM)选题方法;然后将 SM 方法与项目合格(Item Eligibility, IE)方法相结合得到SMIE方法。在此基础上,开展模拟研究比较SM、IE、SMIE、最大修正优先指标(Maximum Modified Priority Index, MMPI)方法、限制阈值(Restrictive Threshold, RT)方法和限制进度(Restrictive Progressive, RPG)方法的选题表现。总体上,它们的测量精度从高到低依次为IE、SM、SMIE、RT、RPG和MMPI方法;项目曝光分布均匀性的优劣次序为MMPI、RPG、SMIE、RT、SM和IE方法;SMIE和RT方法能较好地平衡测量精度和项目曝光均匀性要求。     

认知诊断CAT中具有非统计约束选题方法的比较

项目曝光控制和内容约束关系到测验安全、测验的信度和效度, 是计算机化自适应测验(Computerized Adaptive Testing, CAT)中两类重要的非统计约束条件。本文在认知诊断CAT中针对内容约束和项目曝光控制要求, 运用5种方法选择测验项目。它们分别是：(1) Monte Carlo方法与项目合格方法相结合, 记为MC-IE; (2) Monte Carlo方法与最大优先指标方法相结合, 记为MC-MPI; (3) Monte Carlo方法与限制阈值方法相结合, 记为MC-RT; (4) Monte Carlo方法与限制进度指标方法相结合, 记为MC-RPG以及(5) Monte Carlo方法与最大后验概率方法相结合, 记为MC-PP。然后通过在线性、收敛、发散、无结构和独立五种属性结构下构建题库并运用重参化融融统和模型模拟被试反应比较它们的选题表现。研究发现, (1) 相同选题方法在不同属性结构下项目曝光率的分布类似, 测量精度按线性、收敛、发散、无结构和独立结构的顺序依次降低; (2) 相同属性结构下, 不同方法的测量精度高低依次为MC-PP、MC-IE、MC-RT、MC-MPI和MC-RPG方法; 项目曝光均匀性优劣依次为MC-RPG、MC-MPI、MC-RT、MC-IE和MC-PP方法。统一量纲值表明, MC-RPG方法的综合表现最好, MC-MPI方法的表现次之。     

四种新的基于属性平衡的CD-CAT选题策略开发研究

基于属性平衡的CD-CAT选题策略能够保证每个认知属性被相当数量的题目测量,从而提高被试属性判准率,传统的基于属性平衡的选题策略包括MMGDI法和MGCDI法。本文针对传统的基于属性测量次数平衡选题策略进行改进,提出4种新的基于属性平衡的选题策略：RMGDI、RMCDI、SE-RMGDI、SE-RMCDI,前两种为基于属性测量次数平衡,后两种为基于属性测量精度平衡的选题策略。模拟研究表明：（1）定长CD-CAT条件下,短测验中,MMGDI表现最好,而长测验中,SE-RMGDI和SE-RMCDI的表现优于传统的属性平衡选题策略。（2）不定长CD-CAT条件下,RMGDI在判准率指标上表现优于传统的属性平衡选题策略,4种新的属性平衡策略在测量效率和综合指标上的表现均优于传统的选题策略。     

多维计算机化自适应测验中项目曝光控制选题策略的比较

在MCAT中考查四种项目选择指标在有无曝光控制条件下的选题表现。项目选择指标分别是:(1)贝叶斯的D优化方法(D-optimality)、后验期望Kullback-Leibler方法(KLP)、基于等权重复合分数的最小误差方差方法(the minimized error variance of the linear combination score with equal weight,V1)和基于最优权重复合分数的最小误差方差方法(the minimized error variance of the composite score with optimized weight,V2)。将针对认知诊断CAT项目曝光控制的的限制阈值方法(Restrictive Threshold,RT)和限制进度(Restrictive Progressive,RPG)方法、单维CAT中的最大优先指标方法(Maximum Priority Index,MPI)推广到MCAT。模拟研究表明:(1)KLP,D-优化和V1对领域分数估计准确,能力返真性比V2更好。(2)尽管V1和V2方法相比KLP和D-优化方法提高了题库利用率,但这四种选题指标都产生不均匀的项目曝光率分布。(2)三种曝光控制策略都极大地提高项目曝光均匀性,且不明显降低测量精度。(3)MPI与RPG方法在曝光控制方面表现类似,且比RT的方法表现更好。     

Suicide method runs in families: a birth certificate cohort study of adolescent suicide in Taiwan

Suicide method used by adolescents was examined to determine if it was the same as that employed by their suicidal parents. Six hundred eighty adolescents completed suicide between 1997 and 2007, of whom 12 had parents who had previously died by suicide. The suicide method used by these adolescents was compared with that employed by their suicidal parent and that of a matched peer control adolescent with no exposure to parental suicide and living in the same area. In 10 of the 12 suicidal parent-adolescent dyads, the same suicide method was employed by parent and adolescent. Of seven adolescents whose age at parental suicide was 15 years or above, six used the same suicide method as their suicidal parent had. On the contrary, of 12 exposure-nonexposure suicidal adolescent dyads, the same method was used in only four. Adolescents exposed to parental suicide are more likely to use the suicide method employed by their suicidal parents than the method used by adolescent peers with no exposure to parental suicide.     

The right to die at the end of your life

The Missouri case of Nancy Cruzan brings into sharp focus the medical ethics issue of the right to privacy. It also raises the need for definition of life ranging from cellular to personal. What is it about forced feeding that transforms it into an extraordinary means of nonfunctional treatment? There is the question of balancing benefit and cost (whether personal or financial). Currently we are confronted by the problem of balancing human rights violations against efforts to be “helpful” by the use of heroic medical measures, all of this against the background of ever-changing medical technology.     

Individual response patterns and the effects of different behavioral methods in the treatment of claustrophobia

The importance of individual response patterns in claustrophobic patients was examined in the present study. Thirty-four psychiatric outpatients with a phobia of enclosed spaces were assessed in a small test chamber. During the test their overt behavior was video-taped, heart-rate was measured continuously, and self-ratings of experienced anxiety were made at certain intervals. On the basis of their reactions in the test situation, the patients were divided into two groups showing different response patterns—behavioral and physiological reactors. Within each group the patients were randomly assigned to one behaviorally-focused method (exposure), one physiologically-focused method (applied relaxation) and a waiting-list control group. The patients were treated individually in eight sessions. The between-group comparisons showed that both exposure and applied relaxation were significantly better than the waiting-list condition. Furthermore, exposure yielded better results than applied relaxation for the behavioral reactors, while applied relaxation was better than exposure for the physiological reactors. The improvements were maintained at a follow-up assessment 14 months after the end of treatment. The results support the hypothesis that greater effects are achieved when the method used fits the patient's response pattern than when it does not.     

Therapeutic jurisprudence and the resolution of value conflicts: what we can realistically expect, in practice, from theory

This article assesses the criticisms of therapeutic jurisprudence that it cannot resolve value conflicts, especially between autonomy rights and therapeutic values, or, less radically, that it has not provided a general method for resolving conflicts. Grounded in general jurisprudential principles about conflict resolution, including novel developments respecting the meaning of weighing and balancing, the article rejects the criticisms as unfounded. The article also develops and critiques arguments maintaining that therapeutic jurisprudence cannot resolve certain value conflicts because the values are incommensurable. The argument is illustrated by examples concerning the right to refuse treatment, and jurisprudential analyses of that right.     

变长CD-CAT中的曝光控制与终止规则

本研究借鉴传统计算机化自适应测验的思想, 并结合认知诊断的特点, 在认知诊断框架下提出了4种变长CD-CAT的终止规则, 分别是属性标准误法(SEA)、邻近后验概率之差法(DAPP)、二等分法(HA)以及混合法(HM)。在未控制曝光和采用不同曝光控制条件下, 与HSU法及KL法进行了比较。研究结果表明：(1) 终止条件越严格, 平均测验长度越长, 按测验长度最大值终止的测验百分比越大, 模式判准率越高。(2) 当未加入曝光控制时, 4种新的终止规则均有较好表现, 与HSU法十分接近。随着最大后验概率预设值的增加或e的减小, 模式判准率呈上升趋势, 平均测验长度逐渐增加, 但在题库使用率方面均较差。(3) 当加入项目曝光控制时, 6种变长终止规则下的题库使用率有了极大的提升, 仍能保持较高的模式判准率, 并且不同的曝光控制方法对终止规则的影响是不同的。其中, 相对标准终止规则极易受到曝光控制方法的影响。(4) 综合来看, SEA、HM以及HA法在各项指标上的表现与HSU法基本一致, 其次为KL法和DAPP法。     

Adaptation to continuous perturbation of balance: progressive reduction of postural muscle activity with invariant or increasing oscillations of the center of mass depending on perturbation frequency and vision conditions

We investigated the adaptation of balancing behavior during a continuous, predictable perturbation of stance consisting of 3-min backward and forward horizontal sinusoidal oscillations of the support base. Two visual conditions (eyes-open, EO; eyes-closed, EC) and two oscillation frequencies (LF, 0.2 Hz; HF, 0.6 Hz) were used. Center of Mass (CoM) and Center of Pressure (CoP) oscillations and EMG of Soleus (Sol) and Tibialis Anterior (TA) were recorded. The time course of each variable was estimated through an exponential model. An adaptation index allowed comparison of the degree of adaptation of different variables. Muscle activity pattern was initially prominent under the more challenging conditions (HF, EC and EO; LF, EC) and diminished progressively to reach a steady state. At HF, the behavior of CoM and CoP was almost invariant. The time-constant of EMG adaptation was shorter for TA than for Sol. With EC, the adaptation index showed a larger decay in the TA than Sol activity at the end of the balancing trial, pointing to a different role of the two muscles in the adaptation process. At LF, CoM and CoP oscillations increased during the balancing trial to match the platform translations. This occurred regardless of the different EMG patterns under EO and EC. Contrary to CoM and CoP, the adaptation of the muscle activities had a similar time-course at both HF and LF, in spite of the two frequencies implying a different number of oscillation cycles. During adaptation, under critical balancing conditions (HF), postural muscle activity is tuned to that sufficient for keeping CoM within narrow limits. On the contrary, at LF, when vision permits, a similar decreasing pattern of muscle activity parallels a progressive increase in CoM oscillation amplitude, and the adaptive balancing behavior shifts from the initially reactive behavior to one of passive riding the platform. Adaptive balance control would rely on on-line computation of risk of falling and sensory inflow, while minimizing balance challenge and muscle effort. The results from this study contribute to the understanding of plasticity of the balance control mechanisms under posture-challenging conditions.     

结合a分层的兼具项目曝光和广义测验重叠率控制的选题策略

测验安全和题库使用率在计算机化自适应测验中十分重要, 特别是高风险测验。传统的SHGT法兼具同时控制项目曝光率和广义测验重叠率的功能, 但题库使用率较差。a分层法能够提高题库使用率, 但对过度曝光的项目控制不足。本研究将a分层法的思想与SHGT法相结合, 各取所长, 提出了3种新的选题方法：SHGT_a法, SHGT_b法和SHGT_c法。研究结果表明：(1)与SHGT法相比, 新方法均可以在有效地控制项目曝光率和广义测验重叠率同时, 极大地提高题库使用率; (2)随着预设项目曝光率(rmax)和广义测验重叠率( )取值的增大以及共享人数a的减小, 新方法对被试能力估计的精度呈上升趋势。比起SHGT法, 新方法仍能保持很高的题库使用率; (3)当区分度和难度的相关(rab)较大时, SHGT_b和SHGT_c法在能力估计精度方面优于SHGT_a法; (4)在不同的测验考察内容比例下, 3种新方法对被试能力估计的精度均较好; (5)与SHGT法相比, 新方法能够有效地控制项目曝光率过度控制的问题。     

Minimizing gender differences in children's interest assessment: Development of the Inventory of Children's Activities-3 (ICA-3)

The focus of this study was on revising the Inventory of Children's Activities–Revised (ICA-R; Tracey & Ward, 1998) to enhance its psychometric properties while minimizing gender differences in scale scores. The original 30 ICA-R items and an additional 30 items were administered to 70,280 fifth-eighth grades students. The original scoring was compared to a revised scoring method based solely on the empirically best items and a scoring method balancing empirical scoring with minimizing gender differences. All three item sets (original, empirical, and combined empirical/gender balancing) resulted in strong internal consistency estimates and adequate fit to the circular structure, yet the combined empirical/gender method had much lower gender differences especially for the scales measuring Investigative and Social interests. The implications of using the revised scale with children is discussed.     

A simplified version of the maximum information per time unit method in computerized adaptive testing

In this article, we propose a simplified version of the maximum information per time unit method (MIT; Fan, Wang, Chang, & Douglas, Journal of Educational and Behavioral Statistics 37: 655–670, 2012), or MIT-S, for computerized adaptive testing. Unlike the original MIT method, the proposed MIT-S method does not require fitting a response time model to the individual-level response time data. It is also computationally efficient. The performance of the MIT-S method was compared against that of the maximum information (MI) method in terms of measurement precision, testing time saving, and item pool usage under various item response theory (IRT) models. The results indicated that when the underlying IRT model is the two- or three-parameter logistic model, the MIT-S method maintains measurement precision and saves testing time. It performs similarly to the MI method in exposure control; both result in highly skewed item exposure distributions, due to heavy reliance on the highly discriminating items. If the underlying model is the one-parameter logistic (1PL) model, the MIT-S method maintains the measurement precision and saves a considerable amount of testing time. However, its heavy reliance on time-saving items leads to a highly skewed item exposure distribution. This weakness can be ameliorated by using randomesque exposure control, which successfully balances the item pool usage. Overall, the MIT-S method with randomesque exposure control is recommended for achieving better testing efficiency while maintaining measurement precision and balanced item pool usage when the underlying IRT model is 1PL.