Media Synchronicity, Communication Style and Task: A Dyadic Analysis of Text-based Online Live Chat Customer Services

The Internet has created an environment where many technologies are used to provide net-based customer services. Recently, Online Live Chat Customer Service (OLCCS) has been adopted widely and rapidly on many websites. OLCCS extends traditional customer service channels by using live chats to deliver real-time help and on-demand assistance to online customers’ inquiries. The purpose of this dissertation is to investigate the moderating effects of dyadic communication style and task on the relationship of media synchronicity and performance. Based on Media Synchronicity Theory, lower media synchronicity (text only) will be more appropriate for response tasks; while higher media synchronicity (text and co-browsing) is more likely to improve the performance of procedural tasks. The nature of the dyadic communication style, either implicit or explicit, will also affect the connection between media synchronicity and performance. In addition, the analysis of this dissertation focuses on the level of dyad (representative and customer) that uses text and co-browsing in live chats. The research site selected for this dissertation is a large university library located in the northeastern United States. Excerpts of transcripts were collected from 362 chat sessions in 2004. Content analysis will be used to code these excerpts. Values for the constructs will be assigned based on the coding. ANOVA and multiple regressions will be performed to test the proposed hypotheses

On Finite Time Singularity and Global Regularity of an Axisymmetric Model for the 3D Euler Equations

We investigate the large time behavior of an axisymmetric model for the 3D Euler equations. In \cite{HL09}, Hou and Lei proposed a 3D model for the axisymmetric incompressible Euler and Navier-Stokes equations with swirl. This model shares many properties of the 3D incompressible Euler and Navier-Stokes equations. The main difference between the 3D model of Hou and Lei and the reformulated 3D Euler and Navier-Stokes equations is that the convection term is neglected in the 3D model. In \cite{HSW09}, the authors proved that the 3D inviscid model can develop a finite time singularity starting from smooth initial data on a rectangular domain. A global well-posedness result was also proved for a class of smooth initial data under some smallness condition. The analysis in \cite{HSW09} does not apply to the case when the domain is axisymmetric and unbounded in the radial direction. In this paper, we prove that the 3D inviscid model with an appropriate Neumann-Robin boundary condition will develop a finite time singularity starting from smooth initial data in an axisymmetric domain. Moreover, we prove that the 3D inviscid model has globally smooth solutions for a class of large smooth initial data with some appropriate boundary condition.Comment: Please read the published versio

Two Sides of the Story: Media Choice and Media Use of Web Based eMail and Live Chat Customer Services

Chat services that provide real-time help for customers have been adopted widely and rapidly on many websites in the past few years. Our paper investigates online live chat customer services from two perspectives: media choice between chat service and web e-mail, and media use of chat service analyzed from the perspectives of characteristics, interactivity and socioemotional content. We collected four types of data including system log files, surveys, excerpts of chat transcripts, and unstructured interviews with service representatives. In addition to quantitative data analysis, ATLAS.ti was used to analyze qualitative data in our study. We found that for the purpose of seeking help with questions, more users chose to use web email than chat service. When using the chat service, representatives and users interact with each other through text exchange, page pushing, and co-browsing. They also perform activities such as clarification and attracting attention, and use socioemotional content such as greetings and expressing feelings

Revisiting sample size planning for receiver operating characteristic studies: a confidence interval approach with precision and assurance

Objectives: Estimation of areas under receiver operating characteristic curves (AUCs) and their differences is a key task in diagnostic studies. We aimed to derive, evaluate, and implement simple sample size formulas for such studies with a focus on estimation rather than hypothesis testing. Materials and Methods: Sample size formulas were developed by explicitly incorporating pre-specified precision and assurance, with precision denoted by the lower limit of confidence interval and assurance denoted by the probability of achieving that lower limit. A new variance function was proposed for valid estimation allowing for unequal variances of observations in the disease and non-disease groups. Performance of the proposed formulas was evaluated through simulation. Results: Closed-form sample size formulas were obtained. Simulation results demonstrated that the proposed formulas produced empirical assurance probability close to the pre-specified assurance probability and empirical coverage probability close to the nominal 95%. Real-world worked examples were presented for illustration. Conclusions: Sample size formulas based on estimation of AUCs and their differences were developed. Simulation results suggested good performance in terms of achieving pre-specified precision and assurance probability. An online calculator for implementing the proposed formulas is openly available at https://dishu.page/calculator/.Comment: 28 pages, 3 table