In order to investigate the influence of separation of grade distributions and ratio of common items on the precision of vertical scaling, this simulation study chooses common item design and first grade as base grade. There are four grades with 1,000 students each to take part in a test which has 100 items. Monte Carlo simulation method is used…

Social media is the platforms where users communicate, interact, share ideas, career interest, pictures, video, etc. Social media gives an opportunity to analyze the human behavior. Crime analysis using data from social media such as Newsfeeds, Facebook, Twitter, etc., is becoming one of the emerging areas of research for law enforcement…

Publication of research, innovation, challenges and successes is of critical importance to the evolution of more effective distance education programming. Publication in peer reviewed journal format is the most prestigious and the most widespread form of dissemination in education and most other disciplines, thus the importance of understanding…

This study explores a labelling feature that allows students to tag parts of their online messages. Data comes from four sequentially offered sessions of a graduate education course. Students engaged in two to three online activities in groups of three or four. Students (n = 53) contributed from 0 to 56 labels (M = 12.42, SD = 13.50) and 18 to 114…

Proposes a mathematical model to explain the observed concentration or diversity of nominal classes in information retrieval systems. The Lorenz Curve is discussed, Information Production Process (IPP) is explained, and a heuristic explanation of circumstances in which the model might be used is offered. (30 references) (LRW)

Reviews literature relating to Bradford's Law of Scatter, which groups journals and articles to identify number of periodicals relevant to particular subject, and notes the gap between theoretical and empirical studies, i.e., no relationship has been found between variables which characterize empirical situations and theoretical models. Thirteen…

Explores inter-record linkage relationships of a bibliographic hypertext system through the use of descriptor term co-occurrences. Using term distribution and term exhaustivity data for an existing system, three models of term co-occurrence are developed and tested against the observed data. (Author/LRW)

Examines various kinds of uncertainty in information science. The notion of ambiguity is defined and contrasted with the more familiar notions of randomness and vagueness. Functional forms resistant to ambiguity are defined, and it is shown how to incorporate a random component, that is itself also resistant to ambiguity, into a resilient, but…

Proposes split model for index term distribution in document set that uses rank function for high frequency terms and size function for low frequency terms; the point of transition is determined either empirically or by rule. Distributions to describe index term exhaustivity and term co-occurrence are considered briefly. (36 references) (EJS)

Applies a prefix trie index, or trie hashing, to the problem of providing fast search times, fast load times, and fast update properties in a bibliographic or full-text retrieval system with inverted files. Statistics are given for a test database consisting of an online catalog at the University of Western Ontario. (Author/LRW)

Discusses the problem of determining an adequate sample size for an information retrieval experiment comparing two systems on separate samples of requests. The application of statistical methods to information retrieval experiments is discussed, the Mann-Whitney U Test is used for determining minimum sample sizes, and variables and distributions…

Describes a study that was conducted to model the navigation patterns followed by users when retrieving information in hypertext systems. The development of two frequency distribution models is explained, the influence of search tasks on path patterns is discussed, and further research is described. (Contains 17 references.) (LRW)

Comparing variability of test scores across alternate forms, test conditions, or subpopulations is a fundamental problem in psychometrics. A confidence interval for a ratio of standard deviations is proposed that performs as well as the classic method with normal distributions and performs dramatically better with nonnormal distributions. A simple…

Describes the Archive Retrieval and Analysis System (ARRAS), which provides rapid access to textual data and fast, flexible, open-ended analysis of individual texts; explains why the system should be viewed as a new kind of working environment; and suggests that such systems may influence users' intellectual point of view. (MBR)

Presents a single framework for conducting topic analysis that performs both topic identification and text segmentation. Key characteristics of the framework are: representing a topic by means of a cluster of words closely related to the topic; and employing a stochastic model, called a finite mixture model, to represent a word distribution within…