The interest in developmental sequences and learning hierarchies is growing. One approach to the study of such sequences is to gather data on several variables, each of which corresponds to a stage, step, or phase in the sequence and to examine the associations between the variables as displayed in a contingency table. If the variables are…

Examines the main mathematical approaches to information retrieval, including both algebraic and probabilistic models, and describes difficulties which impede formalization of information retrieval processes. A number of developments are covered where new theoretical understandings have directly led to improved retrieval techniques and operations.…

One approach to the problem of analyzing classroom interaction by use of a Markoff chain is presented. The two sections of the paper present (1) a discusion of Hoel's test of order of a Markoff chain, and a Likelihood Ratio Criterion (LRC) for a two-dependent Markoff chain is given, and (2) a discussion of possible adjustments of Darwin's LRC with…

An Edgeworth approximation for accurate significance probabilities for the Wilcoxon two-sample test is substantially simplified. A method is developed that allows quick calculations of very accurate probabilities. Exact formulas are given for most of the remaining cases, and tables are presented comparing the new simplification to likely…

Retrieval experiments with the Cranfield collection of 1,400 documents used strategies based on a probabilistic model for an initial search and intermediate search when no relevant documents were known. Results show initial strategy is better than conventional strategies in retrieval effectiveness and number of queries needed to retrieve…

Develops mathematical models to characterize the probability of continued use of an integrated office automation system and tests these models on longitudinal data collected from 210 individuals using the IBM Professional Office System (PROFS) at the University of California at Berkeley. Analyses using survival functions and proportional hazard…

Investigates the relationships between the parameters of the Simon-Yule model and the shapes of three bibliometric distributions: Lotka's Law of Scientific Productivity; Bradford's Law of Bibliometric Scattering; and Zipf's Law of Word Frequency. The results indicate that the probability of a new entry determines the characteristics of all three…

Decisions to terminate training for subjects involved with discrete trial experiments in discrimination learning should utilize a probability criterion rather than a deterministic criterion. Furthermore, these decisions should be based upon the number of correct and error responses made by the subject, with the decision made to terminate training…

A method for estimating power scores is described. By way of illustration, it is applied to 21 students who were improperly timed on a standard test. Some empirical results are given in support of the estimation procedure. (Author)

Five models which perform search tasks of the Data Base Access and Search Environment (DBASE) are presented and used for comparison with subject search performance--unconstrained (rule-based, decision theoretic) and constrained (optimal rule-based, rule-based, probabilistic rule-based). Previous experiments and the modeling approach are briefly…

Proposes approach to integrating Boolean and statistical systems where Boolean queries are interpreted as a means of specifying term dependencies in relevant set of documents. Highlights include series of retrieval experiments designed to test retrieval strategy based on term dependence model and relation of results to other work. (18 references)…

Discusses methods of weighting of descriptors in document search patterns together with the concept of relative indexing and conditions which should be satisfied by descriptor weight. A procedure for modifiying document search patterns based on users' informational needs and opinions is outlined, and examples are given. Sixteen references are…

The psychometric research done by G. Rasch between 1951 and 1959, which is explained and illustrated in this book, takes psychometrics from being purely descriptive to being a science of objective measurement. Individual centered statistics require models in which each individual is characterized separately and from which, given adequate data,…

Analyzes a sample of over 4,700 orders for library materials at the University of California, Berkeley, in terms of the probability that the material will arrive and the factors that determine arrival. Models to evaluate the book ordering process are presented, and variables that may affect arrival time are discussed. (six references) (Author/LRW)

This book shows the advantages of Rasch measurement (G. Rasch) for school district testing programs. The results of Rasch methods are contrasted with conventional statistics for assessing student responses to basic skills testing. Chapter 1 shows how the Rasch probability-based method produces measures that are more useful for students, parents,…