This study investigates the relationships between predictors (i.e., personal traits and mobile activities) of smartphone dependency and its impacts on improper phone use, academic performance and perceived sociability. Using a stratified sampling method, a web survey obtained data from 438 undergraduate smartphone users in Singapore. PLS results show that improper phone use is a critical factor...

Stratified medicine requires identifying predictive markers to determine differential treatment effects for subgroups. Ideally, these markers are then validated in prospective randomised trials. However, many of the methods for the analysis and validation of markers are based on there being a single marker. For example, a biomarker stratified trial design typically stratifies on a single binary...

Much attention has been given to sampling design, and the sampling method chosen directly affects the sampling accuracy. The development of spatial sampling theory has lead to the recognition of the importance of taking spatial dependency into account when sampling. This text uses the new Sandwich Spatial Sampling and Inference (SSSI) software as a tool to compare the relative error, coefficien...

A national web-based survey was administered to 700 undergraduate computer science programs in the United States as part of a stratified random sample of 797 undergraduate computer science programs. The 251 program responses (36% response rate) regarding social and professional issues are presented. This article describes the demographics of the respondents, presents results concerning whether ...

These notes are part of the first chapter of a series of lectures given by the author in the spring of 1970. The ultimate aim of these notes will be to prove the theorem that the set of topologically stable mappings form a dense subset of C∞(N,P ) for any finite dimensional manifolds N and P where N is compact. The first chapter is a study of Thom–Whitney theory of stratified sets and stratifie...

This work explores the use of statistical techniques, namely stratified sampling and cluster analysis, as powerful tools for deriving traffic properties at the flow level. Our results show that the adequate selection of samples leads to significant improvements allowing further important statistical analysis. Although stratified sampling is a well-known technique, the way we classify the data p...

Business performance is affected by the quality management practices of the organization. Holistic programs, including the national quality award programs, six-sigma initiatives, and enterprise resource planning (ERP) applications may characterize the highest level of quality initiatives. Arguably, the most popular quality initiative is the ISO 9000 program. The effect of different levels of qu...

Approximately every 10 years the fixed market basket of commodities and services supporting the Consumer Price Index is updated in a process referred to as a revision of the index. Samples of specific items in the fixed market basket are selected within a newly designed, stratified sample of geographic areas on a continuing rotation basis. The prices of the specific items are quoted every month...

The present longitudinal study described developmental patterns of perceived psychological need satisfaction (PNS) from the end of elementary school to the end of high school and their contribution to school adjustment at the end of high school. The first goal thus consisted in estimating whether developmental trajectories of perceived PNS were homogeneous (i.e., all students reported similar d...

Prior user studies in the music information retrieval field have identified different personas representing the needs, goals, and characteristics of specific user groups for a usercentered design of music services. However, these personas were derived from a qualitative study involving a small number of participants and their generalizability has not been tested. The objectives of this study ar...