Post-instrument covariates are often included as controls in instrumental variable (IV) analyses to address a violation of the exclusion restriction. However, we show that such analyses are subject to biases unless strong assumptions hold. Using linear constant-effects models, we present asymptotic bias formulas for three estimators (with and…

Reviews the literature on Bradford's law (i.e., an empirical relationship describing the distribution of scholarly articles in relevant journals). A model for the distribution of articles, based on random partitioning, is presented; and a mathematical formulation for a law of scattering is derived. The relationship of the model to Bradford's law…

Discusses distributed information retrieval systems that take into account the weights of descriptors from thesauri. Topics addressed include a mathematical model for information retrieval subsystems; organization of inverted files; models for the distributed homogeneous information systems; a distributed information retrieval system based on…

Discusses the generalized inverse Gaussian-Poisson (GIGP) process for informetric modeling. Negative binomial distribution is discussed, construction of the GIGP process is explained, zero-truncated GIGP is considered, and applications of the process with journals, library circulation statistics, and database index terms are described. (50…

Identifies a set of objects that is genuinely indigenous to management information systems and constructs a simple model based on them. The model's four basic entities, which define the scope of information theory, are data, information, knowledge, and wisdom. (Contains 46 references.) (KRN)