Some comments on selecting the best of several binomial populations or the bivariate normal population having the largest correlation coefficient

Using variance stabilizing transformations, this note describes approximate solutions to the ranking and selection problem of selecting the best binomial population or the bivariate normal population with the largest correlation coefficient.     

Linking online self-presentation to identity coherence,identity confusion,and social anxiety in emerging adulthood

The present study examined the role of social media in psychosocial development and adjustment in emerging adulthood. Survey data from a diverse college sample of 220 emerging adults (M age ≈ 23, 175 women) were collected and analysed using a series of multiple regressions. Results revealed that emerging adults high in general identity coherence (indicative of high self-concept clarity) reported presenting the real self and the ideal self on Facebook, suggesting that they were more truthful and positively realistic in their online self-presentation. Emerging adults high in general identity confusion (indicative of less self-concept clarity) reported presenting the ideal self and the false self on Facebook, suggesting that they were less truthful, less realistic, and more socially desirable in their online self-presentation. Moreover, emerging adults who experienced both identity coherence and identity confusion reported presenting the false self on Facebook motivated by self-exploration. Emerging adults experiencing high social anxiety reported presenting the false self on Facebook; they engaged in an extensive self-exploratory and socially desirable online self-presentation. Further, emerging adults experiencing both high identity confusion and high social anxiety reported presenting themselves on Facebook in a less truthful manner. Findings have important implications for identity integration during the emerging adulthood transition in the digital age.     

A diagnostic tree model for polytomous responses with multiple strategies

Constructed-response items have been shown to be appropriate for cognitively diagnostic assessments because students’ problem-solving procedures can be observed, providing direct evidence for making inferences about their proficiency. However, multiple strategies used by students make item scoring and psychometric analyses challenging. This study introduces the so-called two-digit scoring scheme into diagnostic assessments to record both students’ partial credits and their strategies. This study also proposes a diagnostic tree model (DTM) by integrating the cognitive diagnosis models with the tree model to analyse the items scored using the two-digit rubrics. Both convergent and divergent tree structures are considered to accommodate various scoring rules. The MMLE/EM algorithm is used for item parameter estimation of the DTM, and has been shown to provide good parameter recovery under varied conditions in a simulation study. A set of data from TIMSS 2007 mathematics assessment is analysed to illustrate the use of the two-digit scoring scheme and the DTM.     

Reverse correlation in neurophysiology

This article presents a review of reverse correlation in neurophysiology. We discuss the basis of reverse correlation in linear transducers and in spiking neurons. The application of reverse correlation to measure the receptive fields of visual neurons using white noise and m-sequences, and classical findings about spatial and color processing in the cortex resulting from such measurements, are emphasized. Finally, we describe new developments in reverse correlation, including “sub-space” and categorical reverse-correlation. Recent results obtained by applying such methods in the orientation, spatial-frequency and Fourier domains have revealed the importance of cortical inhibition in the establishment of sharp tuning selectivity in single neurons.