Zipfian laws for frequency distributions of word pairs and longer phrases are derived from text sample analysis. From crossing of Zipfian curves, it is deduced that number of multi-word phrases that occur frequently in text is surprisingly small, of same order of magnitude as number of individual word-types. (8 references) (EJS)

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)…

A newly introduced approach, rule space, can represent large numbers of erroneous rules of arithmetic operations quantitatively and can predict the likelihood of each erroneous rule. The new model challenges the credibility of the traditional right-or-wrong scoring procedure. (Author/PN)

Describes preliminary investigation of the use of International Computers Limited's Distributed Array Processor (DAP) for parallel searching of large serial files of documents. DAP hardware and software, test collections, measurement of DAP performance, search algorithms, experimental results, and DAP suitability for interactive searching are…

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…

Common mathematical errors of pupils as identified by the Concepts in Secondary Mathematics and Science Project are identified and traced to the use of methods invented by students rather than formally taught methods. (MP)

A computer program named BUGGY is described. The program is designed to duplicate "traditional" student mathematical mistakes; pupils are to identify the nature of the errors the computer makes. (MP)

Activities are described in which number patterns in two-digit multiplication exercises are investigated. (DT)

Presents the text of a message sent to Susan Gerofsky by Robert Thomas after reading her article on a linguistic and narrative view of word problems in mathematics education. Gerofsky's response is also included. (DDR)

Presents a World Wide Web page model that reacts to pre-defined events and performs actions like "prefetching" automatically. Discusses the active index, conceptual page model; design of the client system, status of the current implementation, prefetching algorithm, an experiment of the algorithm, experimental results of the active index…

Describes the development of an English-as-a-Second-Language computer-adaptive test of reading comprehension. The article discusses the constraints that apply to Computer Adaptive Testing (CAT) and the advantages of CAT over conventional testing modalities. (29 references) (Author/CK)

With over 260 schools and 200,000 students, Houston has one of the nation's largest school systems. Population growth, geographic population shifts, and historic policies have all contributed to an undesirable distribution of students within the district. This paper describes an algorithm's use in evaluating competing school capacity plans and…

Three different applications of the testlet concept are presented, and the psychometric models most suitable for each application are described. Difficulties that testlets can help overcome include (1) context effects; (2) item ordering; and (3) content balancing. Implications for test construction are discussed. (SLD)

A probabilistic item response theory (IRT) model is developed for pair-comparison design in which the unfolding principle governing the choice process uses a discriminant process analogous to Thurstone's Law of Comparative Judgment. A simulation study demonstrates the feasibility of estimation, and two examples illustrate the implications for…