Describes a model for a front end query processor to deal with incomplete information in a database. The effectiveness of the processor in restricting the number of objects to be processed in a query and in aiding the interpretation of a query is discussed. (26 references) (Author/CLB)

Numerical tables of mathematical functions are in continual demand by scientists and engineers for preliminary surveys of problems before programming for computing machines. This handbook was designed to provide scientific investigators with a comprehensive and self-contained summary of the mathematical functions that arise in physical and…

A statistical method is described and illustrated which provides confidence envelopes around item response functions. Examples of 95 percent confidence envelopes for the one-, two-, and three-parameter logistic response models are given. In addition, the authors describe N-line plots, which show the genesis of the envelope as well as the density…

Meehl's taxometric method was developed to distinguish categorical and continuous constructs. However, taxometric output can be difficult to interpret because expected results for realistic data conditions and differing procedural implementations have not been derived analytically or studied through rigorous simulations. By applying bootstrap…

Presents a mathematical theory that can be used to define concentration places of objects within unordered classes. The application to research on the evolution of journals and subject areas is illustrated, and an online method of calculating concentration evolution is described. (1 references) (CLB)

Describes how operations on local inverted files are to be modified in order to use them in distributed information retrieval systems based on thesauri. The presented rules may be viewed as the logical approach in implementing a distributed retrieval system consisting of n local retrieval systems. (Author/MBR)

Discusses application of the "Lorenz Curve" (a graphical representation of the concentration of wealth) with the "Gini Coefficient" (an index of inequality) to measure social inequality in school finance studies. Examines the basic assumptions of these measures and suggests a minor reconception. (MCG)

Experimenters sometimes wish to estimate for a particular dependent variable the proportion of total group variance that is associated with mean differences among fixed treatments or subject classifications. Hays (1981) represents this proportion by the parameter omega squared. A point estimate may be easily computed as a function of the number of…

Formulas for estimating cross-validated hit-rates, the number of correct classifications into an a priori grouping structure, were examined. The following mathematical formulas were compared: McLachlan's formula estimator, two Snappin and Knoke smoothed formula estimators, and the analytic leave-one-out estimator. The R method was included as a…

Proposes a new definition of the nuclear zone of a Bradford or Leimkuhler curve. The mathematical rationale is outlined, and examples of the application of this technique to citation analysis are given. (15 references) (CLB)

Investigates the properties of a global model consisting of "n" local information retrieval systems based on thesaurus. Definitions of a distributed information retrieval system (thesaurus, documents set, set of queries) and proofs of theorems denoting further properties of the systems are highlighted. Five references are included. (EJS)

Describes Fermat's last theorem and shows the proof for the case when the exponent is four. Outlines other works for the proof of the theorem, including Kummer's. Twelve references are listed. (YP)

A Bayesian argument is used to suggest modifications to the Robertson and Jones relevance weighting formula to accommodate the addition to the query of terms taken from the relevant documents identified during the search. (Author)

Describes a method for advance estimation of user charges for queries in relational data model-based numeric databases when charges are based on data retrieved. Use of this approach is demonstrated by sample queries to an imaginary marketing database. The principles and methods of this approach and its relevance are discussed. (MBR)

Correlation structure of the Burrell and Cane mixed Poisson model for library loans with aging is presented and illustrated by data from University of Sussex. The approach is compared and contrasted with that originally formulated by Morse and recently reevaluated by Beheshti and Tague. Directions for future investigations are suggested. (Author)