Israel Moiseevich Gelfand (1913–2009)

In this homage to the late I M Gelfand, we try to give an overview of some of his contributions to the theories of Banach algebras in general and C*-algebras in particular, and briefly elaborate on the celebrated Gelfand-Naimark-Segal construction which gives a way of passing from positivity-preserving linear functionals to representations on Hilbert space.     

Young children's learning and transfer of biological information from picture books to real animals

Preschool children (N = 104) read a book that described and illustrated color camouflage in animals (frogs and lizards). Children were then asked to indicate and explain which of 2 novel animals would be more likely to fall prey to a predatory bird. In Experiment 1, 3- and 4-year-olds were tested with pictures depicting animals in camouflage and noncamouflage settings; in Experiment 2, 4-year-olds were tested with real animals. The results show that by 4 years of age, children can learn new biological facts from a picture book. Of particular importance, transfer from books to real animals was found. These findings point to the importance that early book exposure can play in framing and increasing children's knowledge about the world.     

Impaired acuity of the approximate number system underlies mathematical learning disability (dyscalculia)

Many children have significant mathematical learning disabilities (MLD, or dyscalculia) despite adequate schooling. The current study hypothesizes that MLD partly results from a deficiency in the Approximate Number System (ANS) that supports nonverbal numerical representations across species and throughout development. In this study of 71 ninth graders, it is shown that students with MLD have significantly poorer ANS precision than students in all other mathematics achievement groups (low, typically, and high achieving), as measured by psychophysical assessments of ANS acuity (w) and of the mappings between ANS representations and number words (cv). This relation persists even when controlling for domain-general abilities. Furthermore, this ANS precision does not differentiate low-achieving from typically achieving students, suggesting an ANS deficit that is specific to MLD.     

Predicting First Grade Reading Performance from Kindergarten Response to Tier 1 Instruction

Many schools are beginning to implement multi-tier response to intervention (RTI) models for the prevention of reading difficulties and to assist in the identification of students with learning disabilities (LD). The present study was part of our larger ongoing longitudinal RTI investigation within the Florida Learning Disabilities Center grant. This study used a longitudinal correlational design, conducted in 7 ethnically and socio-economically diverse schools. We observed reading instruction in 20 classrooms, examined response rates to kindergarten Tier 1 instruction, and predicted students' first grade reading performance based upon kindergarten growth and end of year reading performance (n = 203). Teachers followed an explicit core reading program and overall, classroom instruction was rated as effective. Results indicate that controlling for students' end of kindergarten reading, their growth across kindergarten on a variety of language and literacy measures suppressed predictions of first grade performance. Specifically, the steeper the students' trajectory to a satisfactory outcome, the less likely they were to demonstrate good performance in first grade. Implications for future research and RTI implementation are discussed.     

Two-stage screening for math problem-solving difficulty using dynamic assessment of algebraic learning

The purpose of this study was to explore the utility of a dynamic assessment (DA) of algebraic learning in predicting third graders' development of mathematics word-problem difficulty. In the fall, 122 third-grade students were assessed on a test of math word-problem skill and DA of algebraic learning. In the spring, they were assessed on word-problem performance. Logistic regression was conducted to contrast two models. One relied exclusively on the fall test of math word-problem skill to predict word-problem difficulty on the spring outcome (less than the 25th percentile). The second model relied on a combination of the fall test of math word-problem skill and the fall DA to predict the same outcome. Holding sensitivity at 87.5%, the universal screener alone resulted in a high proportion of false positives, which was practically reduced when DA was included in the prediction model. Findings are discussed in terms of a two-stage process for screening students within a responsiveness-to-intervention prevention model.     

Examining the accuracy of teachers' judgments of DIBELS performance

The purpose of this investigation was to examine the accuracy of teachers' judgments of students' early literacy skills and to determine if students' achievement levels influenced teachers' judgments. Typical and lower‐achieving kindergarten and first‐grade students' scores on the Nonsense Word Fluency and Phoneme Segmentation Fluency measures of the Dynamic Indicators of Basic Early Literacy Skills (DIBELS) were compared to the predicted performance by their teachers. Results showed a moderately strong correlation between teachers' judgments and students' performance across all of the students, which is consistent with past research. Teachers' judgments, however, consistently and significantly overestimated the actual performance of students, particularly those who were typically performing students. The findings of the investigation suggest that relying on teachers' judgments of students' early literacy skills alone may be insufficient to accurately identify students at risk for reading difficulties. © 2011 Wiley Periodicals, Inc.     

Between the local and the global: organized research units and international collaborations in the health sciences

Organized research units—also known as centers, institutes, and laboratories—are increasingly prominent in the university. This paper examines how ORUs emerge to promote global agendas and international collaborations in an academic health center in North America. The roles these units play in helping researchers work across institutional and national boundaries are identified and analyzed. The concept of boundary organizations is employed to explain the features of ORUs and the challenges they face. Findings provide insight into how such units operate between local and global mandates, interest groups, and sources of influence, helping to extend university research into the global space.     

Spurious Latent Classes in the Mixture Rasch Model

Mixture Rasch models have been used to study a number of psychometric issues such as goodness of fit, response strategy differences, strategy shifts, and multidimensionality. Although these models offer the potential for improving understanding of the latent variables being measured, under some conditions overextraction of latent classes may occur, potentially leading to misinterpretation of results. In this study, a mixture Rasch model was applied to data from a statewide test that was initially calibrated to conform to a 3‐parameter logistic (3PL) model. Results suggested how latent classes could be explained and also suggested that these latent classes might be due to applying a mixture Rasch model to 3PL data. To support this latter conjecture, a simulation study was presented to demonstrate how data generated to fit a one‐class 2‐parameter logistic (2PL) model required more than one class when fit with a mixture Rasch model.     

Problem analysis: Examining the selection and evaluation of data during problem‐solving consultation

The purpose of this study was to analyze how school psychologists engaged in problem analysis during problem‐solving consultation. Five aspects of the problem analysis process were examined: 1) the types of questions participants asked during problem identification, 2) the types of data participants requested, 3) the frequency of requests for each type of data, 4) the use of multiple methods and sources of data across multiple domains, and 5) the criteria used to interpret the data. Four school psychologists were recruited to each complete three fictional consultation cases within a computer‐simulated environment. A qualitative case study method was used. The results of this study revealed how school psychologists used theory, a multidimensional assessment framework, and self‐referent data to analyze a problem. Implications for future research are discussed. © 2011 Wiley Periodicals, Inc.