Internet use, abuse, and dependence among students at a southeastern regional university

OBJECTIVE: To assess Internet use, abuse, and dependence. PARTICIPANTS: 411 undergraduate students. RESULTS: Ninety percent of participants reported daily Internet use. Approximately half of the sample met criteria for Internet abuse, and one-quarter met criteria for Internet dependence. Men and women did not differ on the mean amount of time accessing the Internet each day; however, the reasons for accessing the Internet differed between the 2 groups. Depression was correlated with more frequent use of the Internet to meet people, socially experiment, and participate in chat rooms, and with less frequent face-to-face socialization. In addition, individuals meeting criteria for Internet abuse and dependence endorsed more depressive symptoms, more time online, and less face-to-face socialization than did those not meeting the criteria. CONCLUSIONS: Mental health and student affairs professionals should be alert to the problems associated with Internet overuse, especially as computers become an integral part of college life.     

Weighted nonparametric regression

In the fixed design regression model, additional weights are considered for the Nad a ray a-Watson and Gasser-Miiller kernel estimators. We study their asymptotic behavior and the relationships between new and classical estimators. For a simple family of weights, and considering the AIMSEAS global loss criterion, we show some possible theoretical advantages. An empirical study illustrates the performance of the weighted kernel estimators in theoretical ideal situations and in simulated data sets. Also some results concerning the use of weights for local polynomial estimators are given.     

Pivotal Quantities Based on Sequential Data: A Bootstrap Approach

A bootstrap algorithm is provided for obtaining a confidence interval for the mean of a probability distribution when sequential data are considered. For this kind of data the empirical distribution can be biased but its bias is bounded by the coefficient of variation of the stopping rule associated with the sequential procedure. When using this distribution for resampling the validity of the bootstrap approach is established by means of a series expansion of the corresponding pivotal quantity. A simulation study is carried out using Wang and Tsiatis type tests and considering the normal and exponential distributions to generate the data. This study confirms that for moderate coefficients of variation of the stopping rule, the bootstrap method allows adequate confidence intervals for the parameters to be obtained, whichever is the distribution of data.     

The Developmental Origins of Gaze‐Following in Human Infants

During the first year of life, infants develop the capacity to follow the gaze of others. This behavior allows sharing attention and facilitates language acquisition and cognitive development. This article reviews studies that investigated gaze‐following before 12 months of age in typically developing infants and discusses current theoretical perspectives on early GF. Recent research has revealed that early GF is highly dependent on situational constraints and individual characteristics, but theories that describe the underlying mechanisms have partly failed to consider this complexity. We propose a novel framework termed the perceptual narrowing account of GF that may have the potential to integrate existing theoretical accounts.     

A Bayesian Approach for Multiple Response Surface Optimization in the Presence of Noise Variables

An approach for the multiple response robust parameter design problem based on a methodology by Peterson (2000) is presented. The approach is Bayesian, and consists of maximizing the posterior predictive probability that the process satisfies a set of constraints on the responses. In order to find a solution robust to variation in the noise variables, the predictive density is integrated not only with respect to the response variables but also with respect to the assumed distribution of the noise variables. The maximization problem involves repeated Monte Carlo integrations, and two different methods to solve it are evaluated. A Matlab code was written that rapidly finds an optimal (robust) solution in case it exists. Two examples taken from the literature are used to illustrate the proposed method.     

New critical region tables for Fisher's exact test

The best-known non-asymptotic method for comparing two independent proportions is Fisher's exact text. The usual critical region (CR) tables for this test contain one or more of the following defects:they distinguish between rows and columns; they distinguish between the alternatives H = p1 < p2 and H = p1 > p2; they assume that the error for the two-tailed test is twice that of the one-tailed test; they do not use the optimal version of the test; they do not give both CRs for one and two tails at the same time. All this results in the unnecessary duplication of the space required for the tables, the construction of tables of low-powered methods, or the need to manipulate two different tables (one for the one-tailed test, the other for the two-tailed test). This paper presents CR tables which have been obtained from the most powerful version of Fisher's exact test and which occupy the minimum space possible. The tables, which are valid for one- or two-tailed tests, have levels of significance of 10%, 5% and 1% and values for N (the total size of both samples) of less than or equal to 40. This article shows how to calculate the P value in a specific problem, using the tables as a means of partial checking and as a preliminary step to determining the exact P value.     

Collinearity diagnostic applied in ridge estimation through the variance inflation factor

The variance inflation factor (VIF) is used to detect the presence of linear relationships between two or more independent variables (i.e. collinearity) in the multiple linear regression model. However, the traditionally used VIF definitions encounter some problems when extended to the case of the ridge estimation (RE). This paper presents an extension of the VIF in RE by providing two alternative VIF expressions that overcome these problems in the general case. Some characteristics of these expressions are also presented and compared with the traditional expression. The results are illustrated with an economic example in the case of three independent variables and with a Monte Carlo simulation for the general case.     

Modelling university image: The teaching staff viewpoint

This study proposes a methodology for identification of the main dimensions determining university image and understanding the relative weight of each of these dimensions. This is important for university governance in order to improve the service provided and to develop and maintain a distinctive position giving a competitive advantage. The conclusions and implications deriving from these results suggest actions designed to improve the image of the university.     

Patterns of Attachment and Emotional Competence in Middle Childhood

The study investigated the relationship between patterns of attachment and emotional competence at the beginning of middle childhood in a sample of 122 seven‐year‐olds. A new battery of tasks was developed in order to assess two facets of emotional competence (emotion recognition and knowledge of regulation strategies). Attachment was related to the choice of emotion regulation strategies in hypothetical situations; secure children produced the highest frequency of cognitive engagement strategies (e.g., reappraisal), and disorganized children the lowest. Insecure children produced more behavioral engagement strategies and fewer behavioral diversion ones. There was a minor effect of attachment on emotion recognition, with disorganized children scoring lower in the discrimination of facial expression. Consistent sex differences were also apparent in the direction of a female advantage in emotional competence: Girls scored higher in emotion recognition than boys, and in the regulation knowledge task, they produced fewer helpless answers and more cognitive engagement strategies.