The ability to detect and accurately estimate the strength of interaction effects are critical issues that are fundamental to social science research in general and IS research in particular. Within the IS discipline, a significant percentage of research has been devoted to examining the conditions and contexts under which relationships may vary, often under the general umbrella of contingency theory (cf. McKeen et al. 1994, Weill and Olson 1989). In our survey of such studies, the majority failed to either detect or provide an estimate of the effect size. In cases where effect sizes are estimated, the numbers are generally small. These results have led some researchers to question both the usefulness of contingency theory and the need to detect interaction effects (e.g., Weill and Olson 1989). This paper addresses this issue by providing a new latent variable modeling approach that can give more accurate estimates of interaction effects by accounting for the measurement error that attenuates the estimated relationships. The capacity of this approach at recovering true effects in comparison to summated regression is demonstrated in a Monte Carlo study that creates a simulated data set in which the underlying true effects are known. Analysis of a second, empirical data set is included to demonstrate the technique's use within IS theory. In this second analysis, substantial direct and interaction effects of enjoyment on electronic-mail adoption are shown to exist.

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A Partial Least Squares Latent Variable Modeling Approach for Measuring Interaction Effects: Results from a Monte Carlo Simulation Study and an Electronic-Mail Emotion/Adoption Study

物件導向軟體之架構(Object-Oriented Software Construction)探討

A federated database system (FDBS) is a collection of cooperating database systems that are autonomous and possibly heterogeneous. In this paper, we define a reference architecture for distributed database management systems from system and schema viewpoints and show how various FDBS architectures can be developed. We then define a methodology for developing one of the popular architectures of an FDBS. Finally, we discuss critical issues related to developing and operating an FDBS.

Federated database systems for managing distributed, heterogeneous, and autonomous databases

Graph database models can be defined as those in which data structures for the schema and instances are modeled as graphs or generalizations of them, and data manipulation is expressed by graph-oriented operations and type constructors. These models took off in the eighties and early nineties alongside object-oriented models. Their influence gradually died out with the emergence of other database models, in particular geographical, spatial, semistructured, and XML. Recently, the need to manage information with graph-like nature has reestablished the relevance of this area. The main objective of this survey is to present the work that has been conducted in the area of graph database modeling, concentrating on data structures, query languages, and integrity constraints.

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Survey of graph database models

One of the fundamental principles of the database approach is that a database allows a nonredundant, unified representation of all data managed in an organization. This is achieved only when methodologies are available to support integration across organizational and application boundaries.Methodologies for database design usually perform the design activity by separately producing several schemas, representing parts of the application, which are subsequently merged. Database schema integration is the activity of integrating the schemas of existing or proposed databases into a global, unified schema.The aim of the paper is to provide first a unifying framework for the problem of schema integration, then a comparative review of the work done thus far in this area. Such a framework, with the associated analysis of the existing approaches, provides a basis for identifying strengths and weaknesses of individual methodologies, as well as general guidelines for future improvements and extensions.

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A comparative analysis of methodologies for database schema integration

While knowledge discovery often refers to the process of discovering useful knowledge from data, data mining focuses on the application of algorithms for extracting patterns from data. Knowledge discovery seeks to find patterns in data and to infer rules (that is, to discover new information) that queries and reports do not reveal effectively. Thus, knowledge discovery has a R&D flavor and data mining an operational process one. Data mining is a basis of knowledge discovery.

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Introduction to Data Mining and Knowledge Discovery

A statistical profile summarizes the instances of a database. It describes aspects such as the number of tuples, the number of values, the distribution of values, the correlation between value sets, and the distribution of tuples among secondary storage units. Estimation of database profiles is critical in the problems of query optimization, physical database design, and database performance prediction. This paper describes a model of a database of profile, relates this model to estimating the cost of database operations, and surveys methods of estimating profiles. The operators and objects in the model include build profile, estimate profile, and update profile. The estimate operator is classified by the relational algebra operator (select, project, join), the property to be estimated (cardinality, distribution of values, and other parameters), and the underlying method (parametric, nonparametric, and ad-hoc). The accuracy, overhead, and assumptions of methods are discussed in detail. Relevant research in both the database and the statistics disciplines is incorporated in the detailed discussion.

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Statistical profile estimation in database systems

Information technology acceptance in the internal audit profession: Impact of technology features and complexity

A form model and an expert database system that analyzes instances of the form model to derive a conceptual schema are proposed. The form model describes the properties of form fields such as their origin, hierarchical structure, and cardinality. The expert database design system creates a conceptual schema by incrementally integrating related collections of forms. The rules of the expert systems are divided into six phases form selection; entity identification; attribute attachment; relationship identification; cardinality identification; and integrity constraints. The rules of the first phase use knowledge about the form flow to determine the order in which forms are analyzed. The rules in other phases are used in conjunction with a designer dialog to identify the entities, relationships, and attributes of a schema that represents the collection of forms. >

An expert database design system based on analysis of forms

The concept of an integrated Dictionary/Directory (D/D) System is discussed in detail, and the state of current systems in both the centralized and distributed database environments is surveyed For the centrahzed database environment, three aspects are emphasized: (1) the software tnterfaces between the D / D System and other software packages, (2) the convert functmns of the D / D System, and (3) the environmental dependency between the D / D System and a Database Management System (DBMS). For the distributed database environment, the artmle elucidates the necessary extensions to the centrahzed D/D, the additional software interfaces required, and the use of the D / D as a distributed database. An example of a commercial D / D System that is integrated with a distributed DBMS is presented.

Michael V. Mannino

Papers

Introduction to Data Mining and Knowledge Discovery

Statistical profile estimation in database systems

Information technology acceptance in the internal audit profession: Impact of technology features and complexity

An expert database design system based on analysis of forms

The Integrated Dictionary/Directory System