The mathematical derivation of the statistics used for inference in some linear models assumes that values of the independent variables are pre-selected such that these variables can be treated as fixed rather than random variables. This assumption is often disregarded when these models are utilized in research. This study is an investigation of…

A novel solution to the statistical problems in an evaluation of rare events is described. The significance of variations in the number of child homicides is analyzed in a binary time series of "active" months for monitoring future incidence and related systemic events. (Author/CM)

Discusses the importance of a knowledge of basic statistical concepts for a librarian's education, and the problem of implementing such an introductory course. Two class exercises dealing with sampling and probability and the Central Limit Theorem are described, and 11 references are included. (BK)

Two techniques for interpretation of fitted log-linear models in contingency table analysis are discussed. The use of odds ratios as opposed to direct interpretation of the fitted model is argued for. (Author/JKS)

Discusses a reliability theoretic construct focusing on information produced to satisfy specified purposes or achieve preconceived objectives. When measures of system reliability and sensitivity analyses are performed, the result is a closer congruence between the objectives of the data producer and user requirements. (Author/MBR)

Argues that Gottlieb rejects population sampling and statistical analyses of distributions as he proposes that his experimental brand of mechanistic science is the only legitimate approach to developmental research. Maintains that Gottlieb exaggerates developmental uncertainty, based on his own research with extreme environmental manipulations.…

Describes a procedure for information retrieval testing that is based on the comparison of statistically independent methods of retrieval applied to the same database. The probability ranking principle is discussed, the statistical meaning of relevance is examined, and the methodology is illustrated on a large database of MEDLINE records. (19…

This paper provides a longitudinal perspective on changes in Italian men's earnings inequality since the late 1970s by decomposing the earnings autocovariance structure into its long-term and transitory parts. Cross-sectional earnings differentials grew over the period and the longitudinal analysis shows that such growth was determined by the…

Causal inference is an important, controversial topic in the social sciences, where it is difficult to conduct experiments or measure and control for all confounding variables. To address this concern, the present study presents a probability index to assess the robustness of a causal inference to the impact of a confounding variable. The…

This activity introduces students to the need for and rationale of hypothesis testing, using a basketball scenario familiar to even the most casual of fans.

We present a model allowing the measurement of the returns to plurilingual competences in a small open economy, considered as a reduced model of an open European labour market where different nationalities work together and therefore need to communicate either in one or in multiple languages. Our results suggest that high plurilingual competences…

New capabilities in "TinkerPlots 2.0" supported the conceptual development of fifth- and sixth-grade students as they pursued several weeks of instruction that emphasized data modeling. The instruction highlighted links between data analysis, chance, and modeling in the context of describing and explaining the distributions of measures that result…

For much of the twentieth century, Markov theory and Markov processes have been widely accepted as valid ways to view statistical variables and parameters. In the complex realm of online searching, where researchers are always seeking the route to the best search strategies and the most powerful query terms and sequences, Markov process analysis…

The Pearson and likelihood ratio statistics are frequently used for assessing the absolute fit of probability models. Researchers are often interested in comparing fits provided by different models which may have a subsuming or non-subsuming relation. A subsuming relation exists when the parameters of the reduced model form a subset of those…

A mathematical setting based on a statistical sampling probability mechanism is described. In this setting, a mathematical meaning is given for the information function; and it becomes possible to study the relative merits of various ability-estimating procedures. The maximum likelihood estimation procedure under the one-, two-, three-parameter…