In this paper a reliable method is found for approximating the value of the Bivariate Normal Correlation Coefficient, rho, given values of the joint probability and the normal deviates, h and k, or the related areas. This technique finds useful application in the computation of the tetrachoric correlation coefficient, r, when the underlying…

A test for divisibility by any prime number is discussed and its proof is given. (MP)

A current method of teaching long division using repeated subtraction is analyzed as being an example of a sound mathematical method that falls into disrepute when it results in unnecessary, length calculations. (MP)

Comparisons are made between the errors obtained when approximating the integral with the midpoint rule, the trapezoidal rule, and Simpson's rule. (MP)

This study examined the effectiveness using an automatic algorithm to rank the results of Boolean searches of an inverted file design document retrieval system. Relevant documents were ranked significantly higher than nonrelevant documents on output lists. (Author/KP)

Two difficulties that students have in computing with fractions are idenfitied. Then a procedure is described, stressing the identity element, that resolves these difficulties and increases students' understanding and retention. (MNS)

Presents a model and experimental results of a new one-phase technique for compression text files that is a modification of the Ziv and Lempel compression scheme. The description includes the use of a subword dictionary that is periodically reorganized based on information theory and structural linguistics principles. (29 references) (Author/CLB)

An algorithm or decision chart is presented which provides basic decision steps to help management decide what data should be collected to derive valid and correct objectives, and to determine what levels of objectives will be selected relative to products, outputs, or outcomes of an organization. (MBR)

A description of a Mokken test program to test the robustness of nonparametric Stochastic scales is presented. For each sample and the whole population, different scale statistics (both on scale and on item level) are computed recursively. A statistic T is presented for testing the robustness of the scales in the samples. (Author)

Describes a computerized information retrieval system that uses three agglomerative hierarchic clustering algorithms--single link, complete link, and group average link--and explains their implementations. It is noted that these implementations have been used to cluster a collection of 12,000 documents. (LRW)

Provides an algorithm for determining the median and quartiles of discrete data sets. Describes the graphical equivalent of the numerical method. (JM)

Studies of stereo vision guide research on how animals see and how computers might accomplish this human activity. Discusses a sequence of algorithms to first extract information from visual images and then to calculate the depths of objects in the three-dimensional world, concentrating on stereopsis (stereo vision). (JN)

Views information as residual or catalytic form of energy which regulates other forms of energy in natural and artificial systems. Parallel human information processing (production systems, algorithms, heuristics) and information measurement are discussed. Suggestions for future research in area of parallel information processing include a matrix…

Considers three powerful techniques--heuristics, context trees, and search via backward chaining--that a knowledge engineer might employ to develop an expert system to automate performance engineering, i.e., the branch of instructional technology that focuses on the problems of business and industry. (MBR)

Discusses the functions of using visuals in communicating and comprehending information. (AEA)