Incorporating Uncertainty Into Parallel Analysis for Choosing the Number of Factors via Bayesian Methods

A number of psychometricians have suggested that parallel analysis (PA) tends to yield more accurate results in determining the number of factors in comparison with other statistical methods. Nevertheless, all too often PA can suggest an incorrect number of factors, particularly in statistically unfavorable conditions (e.g., small sample sizes and low factor loadings). Because of this, researchers have recommended using multiple methods to make judgments about the number of factors to extract. Implicit in this recommendation is that, when the number of factors is chosen based on PA, uncertainty nevertheless exists. We propose a Bayesian parallel analysis (B-PA) method to incorporate the uncertainty with decisions about the number of factors. B-PA yields a probability distribution for the various possible numbers of factors. We implement and compare B-PA with a frequentist approach, revised parallel analysis (R-PA), in the contexts of real and simulated data. Results show that B-PA provides relevant information regarding the uncertainty in determining the number of factors, particularly under conditions with small sample sizes, low factor loadings, and less distinguishable factors. Even if the indicated number of factors with the highest probability is incorrect, B-PA can show a sizable probability of retaining the correct number of factors. Interestingly, when the mode of the distribution of the probabilities associated with different numbers of factors was treated as the number of factors to retain, B-PA was somewhat more accurate than R-PA in a majority of the conditions.     

App-Based Manipulatives and Explicit Instruction to Support Division with Remainders

ABSTRACT

In theory, both virtual manipulatives and explicit instruction are viable options to support students with disabilities as they learn mathematics. This study explored the effect of a treatment package—an app-based virtual manipulative (Cuisenaire® Rods) in conjunction with explicit instruction—on students’ acquisition and generalization of solving problems involving division of whole numbers with remainders. Three middle school students with disabilities participated in this multiple baseline, multiple probe across participants single case design study. Each of the students acquired the mathematical behavior of being able to solve division with remainders problems. In other words, a functional relation existed between the intervention package of explicit instruction and the Cuisenaire® Rods app-based manipulative and students’ accuracy in solving division with remainders problems. Yet, two students failed to generalize the skill without the explicit instruction and use of the app-based manipulative.     

Object-naming deficits in developmental dyslexia

This paper reports two experiments which focus on the object naming deficits of dyslexic readers. In Experiment 1, dyslexic and normal readers were asked to name objects depicted by pictures or following their spoken definition. Ten-year-old dyslexics named fewer objects correctly than other children of a similar age, performing only as well as a younger group of 8-year-old normal readers. This was true irrespective of the modality through which they were tested. In terms of naming latency, however, they were similar to comparison groups. In Experiment 2, nine-year-old dyslexic and normal readers performed as well as each other in a receptive vocabulary test in which pictures had to be matched to spoken words. However, once again, on a picture naming test, the dyslexics did less well than controls. We argue that dyslexic children are subject to verbal naming difficulties which cannot be accounted for by generally low levels of vocabulary knowledge. Their problems are attributable not to difficulties in semantic representation but to difficulties with the lexical-phonological representation of spoken words they know. We propose that, in turn, these difficulties are related to their memory and reading problems.     

Teaching in 3D: Pedagogical Affordances and Constraints of 3D Virtual Worlds for Synchronous Distance Learning

Three-dimensional (3D) virtual worlds are a new technology that holds some promise as constructivist learning environments for distance education. This investigation presents an evaluative case study of the pedagogical implications of using one 3D virtual world, Active Worlds, for synchronous distance education. The research design for this qualitative study focuses on the pedagogical affordances and constraints. Methods employed in the data collection include participatory observations, class logs, and formal and informal interviews with the instructor of a synchronous distance learning course offered through Active Worlds University. Findings reveal that although Active Worlds provides tools that support constructivist learning environments, the affordances and constraints of the tools (discourse, experiential, and resource) may, to varying degrees, impact the pragmatic use of this medium. While this initial investigation reveals that this technology supports constructivist learning environments, more research needs to be conducted to fully explore the potential of 3D virtual worlds as both distance and traditional classroom learning environments.     

Learning,using and exchanging global competence in the context of international postgraduate mobility

The paper offers a theoretically grounded analysis of international postgraduate students’ perspectives on the importance and development of global citizenship knowledge and competences while they are studying, and how these are valued and enacted afterwards. It draws on a series of interviews with non-Western international postgraduates during their studies in the UK and upon return to their home countries. It uses the concepts of social and cultural cosmopolitan competences as a framework to discuss the perceived benefits of educational mobility, and the possibilities and limits of social connectedness and openness in the internationalised university environment.     

A Case Study Exploring the Identity of an In-Service Elementary Science Teacher: a Language Teacher First

Teachers are central to providing high-quality science learning experiences called for in recent reform efforts, as their understanding of science impacts both what they teach and how they teach it. Yet, most elementary teachers do not enter the profession with a particular interest in science or expertise in science teaching. Research also indicates elementary schools present unique barriers that may inhibit science teaching. This case study utilizes the framework of identity to explore how one elementary classroom teacher’s understandings of herself as a science specialist were shaped by the bilingual elementary school context as she planned for and provided reform-based science instruction. Utilizing Gee’s (2000) sociocultural framework, identity was defined as consisting of four interrelated dimensions that served as analytic frames for examining how this teacher understood her new role through social positioning within her school. Findings describe the ways in which this teacher’s identity as a science teacher was influenced by the school context. The case study reveals two important implications for teacher identity. First, collaboration for science teaching is essential for elementary teachers to change their practice. It can be challenging for teachers to form an identity as a science teacher in isolation. In addition, elementary teachers new to science teaching negotiate their emerging science practice with their prior experiences and the school context. For example, in the context of a bilingual school, this teacher adapted the reform-based science curriculum to better meet the unique linguistic needs of her students.

     

Children with reported histories of sexual abuse: utilizing multiple perspectives to understand clinical and psychosocial profiles

OBJECTIVE: The current study examines multiple empirically based perspectives (i.e., child, caregiver, and clinician) of behavior and functioning as they contribute to the clinical and psychosocial profile of children (aged 5 to 17.5 years) with reported histories of sexual abuse.METHOD: A large, multi-site data set of children referred into Comprehensive Community Mental Health Services both with and without reported histories of sexual abuse, was examined. Seven hundred and fifty-nine children with a reported history of sexual abuse were compared to 2722 without such a history on caregiver and child reported behavior, clinician rated functioning, diagnosis, demographic variables, and life challenges.RESULTS: The multiple perspectives contributed unique and specific information to regression models: caregiver-reported behavior contributed information about externalizing behavior while child-reported behavior added information about internalizing behavior and clinician ratings about self-harmful behavior. Children with reported histories of sexual abuse were also more likely to be female, Caucasian, and have reported histories of life challenges (e.g., physical abuse, substance use, running away). Child sexual abuse was associated with higher rates of depression and anxiety diagnoses, and lower rates of substance abuse, conduct, and attention deficit disorder diagnoses.CONCLUSIONS: The findings indicate that the profile of children entering into Comprehensive Community Mental Health Services with reported histories of sexual abuse, as compared to those without such histories, is complex and best understood via multiple perspectives. Caregiver, child and clinician rated information, when taken together, provide a comprehensive clinical and psychosocial profile around which to plan and implement individualized service plans.     

Visual and auditory memory: Relationships to reading achievement

In two experiments, visual and auditory memory was tested for good and for poor readers from the upper elementary grades. Under experimenter-blind conditions, no reading group differences existed for single mode presentation in recognition frequency or recognition latency. With a multimodal presentation, latencies for poor readers were similar to those for the single mode presentation. Good readers, however, had significantly faster latencies with multiple input. Generally, results supported dual coding and self-terminating memory search hypotheses for previously encoded stimuli. Implications of the latency differences between reader groups were discussed with respect to the reading process and reading theory.