Results 1 - 10 of 12,093

Estimating the number of clusters in a dataset via the Gap statistic

by Robert Tibshirani, Guenther Walther, Trevor Hastie , 2000
"... We propose a method (the \Gap statistic") for estimating the number of clusters (groups) in a set of data. The technique uses the output of any clustering algorithm (e.g. k-means or hierarchical), comparing the change in within cluster dispersion to that expected under an appropriate reference ..."
Abstract - Cited by 502 (1 self) - Add to MetaCart
We propose a method (the \Gap statistic") for estimating the number of clusters (groups) in a set of data. The technique uses the output of any clustering algorithm (e.g. k-means or hierarchical), comparing the change in within cluster dispersion to that expected under an appropriate reference

Estimating Wealth Effects without Expenditure Data— or Tears

by Deon Filmer, Lant Pritchett - Policy Research Working Paper 1980, The World , 1998
"... Abstract: We use the National Family Health Survey (NFHS) data collected in Indian states in 1992 and 1993 to estimate the relationship between household wealth and the probability a child (aged 6 to 14) is enrolled in school. A methodological difficulty to overcome is that the NFHS, modeled closely ..."
Abstract - Cited by 871 (16 self) - Add to MetaCart
reasonable coherence with current consumption expenditures and most importantly, works as well, or better, than traditional expenditure based measures in predicting enrollment status. When the asset index is applied to the Indian data the results show large, and variable, wealth gaps in the enrollment

Has the U.S. Economy Become More Stable? A Bayesian Approach Based on a Markov-Switching Model of Business Cycle

by Chang-Jin Kim, Charles R. Nelson , 1999
"... We hope to be able to provide answers to the following questions: 1) Has there been a structural break in postwar U.S. real GDP growth toward more stabilization? 2) If so, when would it have been? 3) What's the nature of the structural break? For this purpose, we employ a Bayesian approach to d ..."
Abstract - Cited by 426 (15 self) - Add to MetaCart
narrowing gap between growth rates during recessions and booms is at least as important as a decline in the volatility of shocks.

Idea gaps and object gaps in economic development.

by Paul Romer - Journal of Monetary Economics , 1993
"... A nation that lacks physical objects like factories and roads suffers from an object gap. A nation that lacks the knowledge used to create value in a modern economy suffers from an idea gap. Object gaps are emphasized by mainstream economists who make use of formal models and statistical hypothesis ..."
Abstract - Cited by 212 (0 self) - Add to MetaCart
hypothesis tests. Idea gaps are emphasized by dissident economists who make use of a diverse body of evidence and avoid formal models. Economists need to use the formal models from the first approach and the diverse evidence from the second to fully appreciate the importance of idea gaps in economic

The Intellectual Challenge of CSCW: The Gap Between Social Requirements and Technical Feasibility

by Mark S. Ackerman - Human-Computer Interaction , 2000
"... Over the last 10 years, Computer-Supported Cooperative Work (CSCW) has identified a base set of findings. These findings are taken almost as assumptions within the field. In summary, they argue that human activity is highly flexible, nuanced, and contextualized and that computational entities such a ..."
Abstract - Cited by 225 (12 self) - Add to MetaCart
attesting the continued centrality of this gap could be one of the important intellectual contributions of CSCW. This paper also argues that the challenge of the social-technical gap creates an opportunity to refocus CSCW as a Simonian science of the artificial. To be published in Human-Computer Interaction

Bridging the Gap: A Genre Analysis of Weblogs

by Susan C. Herring, et al.
"... Weblogs (blogs)—frequently modified web pages in which dated entries are listed in reverse chronological sequence—are the latest genre of Internet communication to attain widespread popularity, yet their characteristics have not been systematically described. This paper presents the results of a con ..."
Abstract - Cited by 204 (11 self) - Add to MetaCart
are interlinked, interactive, and oriented towards external events, and underestimate the importance of blogs as individualistic, intimate forms of self-expression. Based on the profile generated by the empirical analysis, we consider the likely antecedents of the blog genre, situate it with respect

Use of receiver operating characteristic (ROC) analysis to evaluate sequence matching

by Michael Gribskov, Nina L. Robinson - Computers and Chemistry , 1996
"... In this paper, we borrow the idea of the Receiver Operating Characteristic (ROC) from clinical medicine and demonstrate its application to sequence comparison. The ROC includes elements of both sensitivity and specificity, and is a quantitative measure of the usefulness of a diagnostic. The ROC is u ..."
Abstract - Cited by 265 (5 self) - Add to MetaCart
idiosyncratic, but the best PAM distance for database searches using the Smith-Waterman method is somewhat larger than predicted by theoretical methods, about 200 PAM. The length independent gap penalty (gap initiation penalty) is quite important, but shows a broad peak at values of about 20- 24. The length

UNIX Disk Access Patterns

by Chris Ruemmler, John Wilkes , 1993
"... Disk access patterns are becoming ever more important to understand as the gap between processor and disk performance increases. The study presented here is a detailed characterization of every lowlevel disk access generated by three quite different systems over a two month period. The contributions ..."
Abstract - Cited by 277 (20 self) - Add to MetaCart
Disk access patterns are becoming ever more important to understand as the gap between processor and disk performance increases. The study presented here is a detailed characterization of every lowlevel disk access generated by three quite different systems over a two month period

A Taxonomy of Software Visualization

by Blaine A. Price, Ian S. Small, Ronald M. Baecker - Journal of Visual Languages and Computing , 1992
"... Software visualization is the use of interactive computer graphics, typography, graphic design, animation, and cinematography to enhance the interface between the software engineer or the computer science student and their programs. Although several taxonomies of software visualization have been pro ..."
Abstract - Cited by 263 (6 self) - Add to MetaCart
proposed, they use few dimensions and do not span the space of important distinctions between systems. We attempt to fill this gap in the literature by proposing a novel and systematic taxonomy of six areas making up thirty characteristic features of software visualization technology. The taxonomy

Understanding the Black-White Test Score Gap

by G. Fryer, Steven D. Levitt - in the First Two Years of School.” Review of Economics and Statistics 86 , 2004
"... Abstract—In previous research, a substantial gap in test scores between white and black students persists, even after controlling for a wide range of observable characteristics. Using a newly available data set (the Early Childhood Longitudinal Study), we demonstrate that in stark contrast to earlie ..."
Abstract - Cited by 184 (9 self) - Add to MetaCart
to earlier studies, the black-white test score gap among incoming kindergartners disappears when we control for a small number of covariates. Real gains by black children in recent cohorts appear to play an important role in explaining the differences between our � ndings and earlier research
Results 1 - 10 of 12,093