This paper identifies typical sampling problems, including improper application of the Central Limit Theorem, that are associated with the probability-based sampling procedures currently used in clinical psychology research. It then presents two alternative research designs, the theory validation model and the extended case study model, which…

Features and tools to outline and shape the long-term learning process for ratio are presented, with examples. Ratio-anticipating activity and creating visual models and schemes are stressed, with the basis for a theory of teaching and learning ratio presented. (MNS)

This report documents the results of a survey of 1,137 active-duty military families, including activated Reservists, regarding child care use. These survey data were analyzed to estimate the relationship between individual family characteristics and installation characteristics and the probability that the family uses any nonparental child care,…

This study with 45 institutionalized individuals with mental retardation and self injurious behavior (SIB) calculated conditional probability using sequential analysis techniques. It found that successive episodes of self-injury were sequentially dependent and this association was not related to frequency or rate of occurrence. The best predictor…

This volume contains the full text of 2 plenary papers and 26 research reports. In addition, brief, usually one-page, reports are provided for 6 discussion groups, 10 technology focus groups, 7 symposiums, 7 oral presentations, and 17 position sessions. The two full plenary reports are: (1) "Problems of Reification: Representations and…

Presents a coordination level matching algorithm to be used in document retrieval systems that incorporate relevance feedback strategies. It is argued that this algorithm may eliminate the need for the frequent reevaluation of documents that is currently found in such systems, and conditions under which reranking is unnecessary are given.…

Examines library availability studies for the past 50 years as a measure of library effectiveness and looks at their differing sources of study samples, methods for gathering data, categories of nonavailability, and data analysis. The Kantor branching technique developed in 1976 is described as the standard analysis method. (Author/EM)

Investigated are three misconceptions of probability and the differential effect of two activity-based instructional units. Response categories (law of averages, law of small numbers, and availability) are identified. Treatment differences (evaluation or no evaluation) appear to influence subjects' interpretations of the information. (YP)

The goal of books in this series is to present work that is on the growing tip of research in cognitive development. The theme of this volume is children's logical and mathematical cognition, a field in which Piaget's influence has been extensive. In the first of the six chapters, Acredolo presents a new theory of the cognitive bases for…

Examines a statistical model in which the users of an online system continually update their estimated probability of success, and quit or continue the search according to the expected utility of each action. The implications for search strategies are discussed. (Author/EM)

Describes probabilistic document retrieval systems as a sequential learning process, in which the system learns the parameters of probability distributions describing the frequencies of feature occurrences in relevant and nonrelevant documents. Several techniques for estimating the parameters of distributions are described and the results of tests…

Describes a study to determine middle school children's representational strategies to form part-whole or part-part relationships for relational numbers such as proportions, ratios, or fractions. Quantitative and qualitative analysis revealed that children prefer a part-part representation to solve relational quantity problems. (15 references)…

Results of the most recent administration of the National Assessment of Educational Progress (NAEP) suggest that the majority of secondary students believe in the independence of random events. In the study reported here, a high percentage of high school and college students answered similar problems correctly. However, about half of the students…

Forty-eight students with no previous exposure to probability or statistics read one of three textbooks that varied in emphasis placed on rote and conceptual learning of basic elementary probability concepts. Findings, among others, show students who read textbooks emphasizing conceptual learning tended to be less sensitive to surface features.…

Examines hypotheses and strategies used by children at the kindergarten, second-, fourth- and sixth-grade levels in making proportional judgements. The task involved 36 trials in which the child had to choose between two groups to obtain a target-color "chip." Results generally conformed to the developmental sequence proposed by Piaget…