Discussion of user queries in information retrieval highlights the experimental evaluation of an adaptive linear model that constructs improved query vectors from user preference judgments on a sample set of documents. The performance of this method is compared with that of standard relevance feedback techniques. (28 references) (LRW)

Reviews the development and the principal elements of total quality management (TQM) and demonstrates methods for introducing some of the key elements into a strategy-oriented business simulation game that can be used to teach future managers. Topics discussed include increased focus on the customer; continuous improvement; and competitive…

A solution of the convection-dispersion equation is used to describe the solute breakthrough curves generated in the demonstrations in the companion paper. Estimation of the best fit model parameters (solute velocity, dispersion, and retardation) is illustrated using the method of moments for an example data set. (Author/MDH)

Describes an evaluation model for expansion systems in information retrieval, i.e., systems expanding a user selection of documents to provide the user with a larger set of documents sharing the same or related characteristics. Highlights include a test protocol and evaluation measures for the efficiency of expansion systems. (Contains 29…

Discusses precision and recall in information science and proposes a new model based on fractal geometry for clusters of relevant documents. Search strategies for retrieving a group of relevant documents are reviewed; fractal sets and chaotic processes are described; and the new model is explained. (Contains 43 references.) (LRW)

Provides an introduction to structural equation modelling (SEM) for language research, including: general objectives of SEM applications relevant to language assessment; methodology and statistical assumptions about data that must be met; commonly-used SEM steps and concepts; application matters, with sample models; and recent critical discussions…

Presented are forms of harmonic oscillator attraction and Coulomb wave functions which can be explicitly constructed and which lead to numerical results for the energy eigenvalues and eigenfunctions of the atomic system. The Schrodinger equation and its solution and specific cases of muonic atoms illustrating numerical calculations are included.…

Investigates the related characteristics of asynchronous learning material used for distance education and Web-based instruction and proposes a material characteristics model. Discusses the relationship among the degree of difficulty of the material, student characteristics, and student abilities; social factors; suitability of teaching materials…

Discusses the use of mathematical modeling. Describes types, examples, and importance of mathematical models. (YP)

Describes the use of step-functions in modelling instruction. Classifies modelling into three categories: direct, analogical, and creative application. Provides and discusses modelling postal rates and other problems as examples. (YP)

Proposes a new learning algorithm to improve the retrieval effectiveness of the search system used in the hypertext environment using an extended Boolean model with links to improve the ranking of retrieved items. Highlights include the basic retrieval scheme, the learning scheme, and a review of basic probabilistic retrieval models. (Contains 32…

Proposes a model for technical journal deselection based on the Bradford law of distribution. The model's operational prescriptives, characteristics of the Bradford distribution in the field of pediatrics, and relevance to collection management are discussed. (42 references) (KRN)

Discusses a misconception about the cycloid that asserts the final point on the path of shortest time in the "Brachistochrone" problem is at the lowest point on the cycloid. Uses a BASIC program for Newton's method to determine the correct least-time cycloid. (MDH)

Discussion of the use of Latent Semantic Indexing to determine relevancy in information retrieval focuses on statistical regression and Bayesian methods. Topics include keyword searching; a multiple regression model; how the regression model can aid search methods; and limitations of this approach, including complexity, linearity, and…

This paper focuses on model interpretation issues and employs a geometric approach to compare the potential value of using the Grade of Membership (GoM) model in representing population heterogeneity. We consider population heterogeneity manifolds generated by letting subject specific parameters vary over their natural range, while keeping other…