Checking the Assumptions of Rasch's Model for Speed Tests

Two new tests for a model for the response times on pure speed tests by Rasch (1960) are proposed. The model is based on the assumption that the test response times are approximately gamma distributed, with known index parameters and unknown rate parameters. The rate parameters are decomposed in a subject ability parameter and a test difficulty parameter. By treating the ability as a gamma distributed random variable, maximum marginal likelihood (MML) estimators for the test difficulty parameters and the parameters of the ability distribution are easily derived. Also the model tests proposed here pertain to the framework of MML. Two tests or modification indices are proposed. The first one is focused on the assumption of local stochastic independence, the second one on the assumption of the test characteristic functions. The tests are based on Lagrange multiplier statistics, and can therefore be computed using the parameter estimates under the null model. Therefore, model violations for all items and pairs of items can be assessed as a by-product of one single estimation run. Power studies and applications to real data are included as numerical examples.     

Selective influence through conditional independence

Let each of several (generally interdependent) random vectors, taken separately, be influenced by a particular set of external factors. Under what kind of the joint dependence of these vectors on the union of these factor sets can one say that each vector is selectively influenced by “its own” factor set? The answer proposed and elaborated in this paper is: One can say this if and only if one can find a factor-independent random vector given whose value the vectors in question are conditionally independent, with their conditional distributions selectively influenced by the corresponding factor sets. Equivalently, the random vectors should be representable as deterministic functions of “their” factor sets and of some mutually independent and factor-independent random variables, some of which may be shared by several of the functions.     

Nonparametric IRT: Testing the bi-isotonicity of isotonic probabilistic models (ISOP)

Nonparametric tests for testing the validity of polytomous ISOP-models (unidimensional ordinal probabilistic polytomous IRT-models) are presented. Since the ISOP-model is a very general nonparametric unidimensional rating scale model the test statistics apply to a great multitude of latent trait models. A test for the comonotonicity of item sets of two or more items is suggested. Procedures for testing the comonotonicity of two item sets and for item selection are developed. The tests are based on Goodman-Kruskal's gamma index of ordinal association and are generalizations thereof. It is an essential advantage of polytomous ISOP-models within probabilistic IRT-models that the tests of validity of the model can be performed before and without the model being fitted to the data. The new test statistics have the further advantage that no prior order of items or subjects needs to be known.     

Field Independence and Change Agent Correlation in Emerging Communities of Irian Jaya,Indonesia

Communities that are limited by oral traditions find theological truths communicated by missions a challenge to understand. Currently, linguists work in many of these minority language groups in order to create vital written languages and produce various literature titles that include the Scriptures. Development of a writing system requires indigenous language assistants who are adept in drawing meaning from unfamiliar cultural paradigms and accurately articulating them. Empirical studies in cognitive style conducted among the minority language groups of Irian Jaya, Indonesia show a correlation between field independence (a dimension of cognitive style) and the ability to grasp abstract linguistic concepts. The Brantley/Larsen Test was developed to identify language assistants, also known as change agents, in a culturally appropriate manner for Irian Jaya. Furthermore, this study suggests that the church would benefit from community lay counselors who manifest field independence, which indicates comprehension of abstract and complex linguistic notions found in Scriptures.Indonesia as Organizational Consultant;     

FOK判断等级及其准确性的实验研究

通过实验集中探讨了FOK判断等级及其准确性的影响因素。实验以中文字串为学习材料,使用组内设计的实验方法研究了被激活信息的量和强度对FOK等级及准确性的影响。实验结果表明：FOK判断的等级是由被激活信息的总量决定的,和被激活信息的正确与否无关;FOK判断的准确性是由被激活信息的强度决定的;且二者之间是有内在联系的。     

认知方式与幼儿部分遮挡绘画关系的研究

本研究考察了５—６岁儿童不同认知方式对部分遮挡绘画任务的影响。实验设定不同形式的误导情境,共有两部分组成。研究结果表明：１．儿童绘画表征水平的发展存在个别差异。２．在误导情境下,场独立儿童比场依存儿童能保持较稳定的策略选择倾向。３．画两个相同物体的遮挡要难于画两个不同物体的遮挡。４．在符号概念编码和空间编码中间存在着一些过渡形态。     

The emergence of untrained mands and tacts in children with autism

Despite Skinner's (1957) assertion that verbal operants are initially functionally independent, recent studies have suggested that in some cases the acquisition of one verbal operant (e.g., mand) gives rise to the other (e.g., tact) without explicit training. The present study aimed to evaluate the functional independence of mands and tacts during instruction with children with autism. Four boys with autism (3 to 6 years old) were taught to construct two 4‐piece structures. Two participants were taught directly to mand, whereas the other 2 were taught to tact the names of the pieces. The effects of training were evaluated in a multiple probe design across verbal operants and tasks. Three of the 4 participants demonstrated an immediate transfer of control from 1 verbal operant to the other. These results were consistent with previous research with typically developing young children.     

Differential developmental trajectories for egocentric, environmental and intrinsic frames of reference in spatial memory

We studied the development of spatial frames of reference in children aged 3-6 years, who retrieved hidden toys from an array of identical containers bordered by landmarks under four conditions. By moving the child and/or the array between presentation and test, we varied the consistency of the hidden toy with (i) the body, and (ii) the testing room. The toy's position always remained consistent with (iii) the array and bordering landmarks. We found separate, additive performance advantages for consistency with body and room. These effects were already present at 3 years. A striking finding was that the room effect, which implies allocentric representations of the room and/or egocentric representations updated by self-motion, was much stronger in the youngest children than the body effect, which implies purely egocentric representations. Children as young as 3 years therefore had, and greatly favoured, spatial representations that were not purely egocentric. Viewpoint-independent recall based only on the array and bordering landmarks emerged at 5 years. There was no evidence that this later-developing ability, which implies object-referenced (intrinsic) representations, depended on verbal encodings. These findings indicate that core components of adult spatial competence, including parallel egocentric and nonegocentric representations of space, are present as early as 3 years. These are supplemented by later-developing object-referenced representations.     

Investigating the mediating role of self-construal on the relationship between cultural group (Malay and Australian) and the characteristics and functional use of autobiographical memory

ABSTRACT

Cultural differences in autobiographical memory characteristics and function have often been presumed to be associated with different cultural beliefs related to the self. The current research aimed to investigate whether self-construal mediated the relationship between cultural group and the characteristics and functional use of autobiographical memory. Caucasian Australians (n?=?71) and Malay Malaysians (n?=?50) completed an online questionnaire that included the Self-Defining Memory task, the Thinking About Life Experiences Revised Questionnaire and the Self Construal Scale. As expected, the Australian group provided longer, more autonomously oriented, specific memories than the Malay group. However, contrary to our predictions, self-construal did not mediate the relationships between cultural group and memory characteristics. The Malay group reported more frequently using autobiographical memories for self-continuity than the Australian group. Finally, there was support for an indirect pathway between cultural group and use of autobiographical memories for self-continuity and social-bonding through self-construal (i.e. independent self relative to interdependent self). The findings highlight the importance of explicitly examining values assumed to be associated with autobiographical remembering, and relating these values to memory characteristics and function.     

A Review of: “Greenwald,R. (2009). Treating Problem Behaviors: A Trauma-Informed Approach.”

This single-case-design experiment examined an intervention to decrease bed-sharing in children, ages 2 through 6. Three sessions were conducted with each parent. At the first session, parents described bed-sharing history and began collecting baseline data. At the second session, parents were instructed to employ the intervention. At the third session, parents were interviewed and offered continued support, if needed. Participants included three children who slept with their parents 4 or more nights per week. The intervention resulted in a substantial decrease in bed-sharing behavior for all participants, and parents reported being satisfied with the intervention.