Listing 1 - 10 of 34 | << page >> |
Sort by
|
Choose an application
"How large a sample size do I need for my study"? Although one of the most commonly-asked questions in statistics, the importance of proper sample size estimation seems to be overlooked by many preclinical researchers. Over the past two decades, numerous reviews of the published literature indicate many studies are too small to answer the research question and results are too unreliable to be trusted. Few published studies present adequate justification of their chosen sample sizes, or even report the total number of animals used. On the other hand, it is not unusual for protocols (usually those involving mouse models) to request preposterous numbers of animals, sometimes in the tens or even hundreds of thousands, "because this is an exploratory study, so it is unknown how many animals we will require"--
Animal Experimentation. --- Sample Size. --- Expérimentation animale. --- Échantillonnage.
Choose an application
Cross-Over Studies --- Data Interpretation, Statistical --- Sample Size --- Statistical Distributions --- Models, statistical --- Clinical Trials as Topic
Choose an application
Clinical medicine --- Drug development --- Sampling (Statistics) --- Sample Size. --- Biometry --- Research --- Statistical methods. --- Statistical methods. --- methods.
Choose an application
Focusing on an integral part of pharmaceutical development, Sample Size Calculations in Clinical Research, Second Edition presents statistical procedures for performing sample size calculations during various phases of clinical research and development. It provides sample size formulas and procedures for testing equality, noninferiority/superiority, and equivalence. A comprehensive and unified presentation of statistical concepts and practical applications, this book highlights the interactions between clinicians and biostatisticians, includes a well-balanced summary of current and emerging clinical issues, and explores recently developed statistical methodologies for sample size calculation. Whenever possible, each chapter provides a brief history or background, regulatory requirements, statistical designs and methods for data analysis, real-world examples, future research developments, and related references. One of the few books to systematically summarize clinical research procedures, this edition contains new chapters that focus on three key areas of this field. Incorporating the material of this book in your work will help ensure the validity and, ultimately, the success of your clinical studies.
Mathematical statistics --- Clinical medicine --- Drug development --- Sampling (Statistics) --- Sample Size --- Biometry --- Research --- Statistical methods --- methods --- Sample Size. --- Statistical methods. --- methods. --- Sampling (Statistics). --- Clinical medicine - Research - Statistical methods --- Drug development - Statistical methods --- Biometry - methods
Choose an application
Quantitative methods in social research --- Sample Size --- Clinical Trials as Topic --- Mathematical Computing --- Regression Analysis --- Sampling Studies --- Sample Size. --- Clinical Trials as Topic. --- Mathematical Computing. --- Regression Analysis. --- Sampling Studies.
Choose an application
Clinical Trials as Topic --- Sample Size --- Clinical trials --- Sampling (Statistics) --- Etudes cliniques --- Echantillonnage (Statistique) --- methods --- Statistical methods --- Méthodes statistiques --- Méthodes statistiques --- Sample Size. --- methods. --- Clinical trials - Statistical methods --- Clinical Trials as Topic - methods
Choose an application
Randomized Controlled Trials as Topic --- Randomized Controlled Trials as Topic --- Sample Size --- Placebos --- methods --- statistics & numerical data
Choose an application
Research Design --- Clinical Trials as Topic --- Sample Size --- Statistics as Topic --- Clinical trials --- Etudes cliniques --- Tables. --- Tables. --- Tables. --- Tables. --- Statistical methods --- Tables. --- Méthodes statistiques --- Tables
Choose an application
The Knowledge Assessment Methodology (KAM) database measures variables that may be used to assess the readiness of countries for the knowledge economy and has many policy uses. Formal analysis using KAM data is faced with the problem of which variables to choose and why. Rather than make these decisions in an ad hoc manner, the authors recommend factor-analytic methods to distill the information contained in the many KAM variables into a smaller set of "factors." Their main objective is to quantify the factors for each country, and to do so in a way that allows comparisons of the factor scores over time. The authors investigate both principal components as well as true factor analytic methods, and emphasize simple structures that help provide a clear political-economic meaning of the factors, but also allow comparisons over time.
Correlation --- Correlations --- Covariance --- Data --- E-Business --- Errors --- Factor Analysis --- Information Security and Privacy --- Matrices --- Matrix --- Measurement --- Missing Data --- Orthogonality --- Population Parameters --- Principal Components Analysis --- Private Sector Development --- Regression Analysis --- Sample Size --- Samples --- Science and Technology Development --- Scientists --- Standard Errors --- Stata --- Statistical and Mathematical Sciences --- Variables
Choose an application
Many highly-disaggregated cross-country indicators of institutional quality and the business environment have been developed in recent years. The promise of these indicators is that they can be used to identify specific reform priorities that policymakers and aid donors can target in their efforts to improve institutional and regulatory quality outcomes. Doing so however requires evidence on the partial effects of these many very detailed variables on outcomes of interest, for example, investor perceptions of corruption or the quality of the regulatory environment. In this paper we use Bayesian Model Averaging (BMA) to systematically document the partial correlations between disaggregated indicators and several closely-related outcome variables of interest using two leading datasets: the Global Integrity Index and the Doing Business indicators. We find major instability across outcomes and across levels of disaggregation in the set of indicators identified by BMA as important determinants of outcomes. Disaggregated indicators that are important determinants of one outcome are on average not important determinants of other very similar outcomes. And for a given outcome variable, indicators that are important at one level of disaggregation are on average not important at other levels of disaggregation. These findings illustrate the difficulties in using highly-disaggregated indicators to identify reform priorities.
Access to information --- Algorithms --- Causation --- Correlations --- Econometrics --- Economic activity --- Economic development --- Economic growth --- Economic Theory & Research --- Economists --- Empirical analysis --- Empirical evidence --- Environment --- Environmental Economics & Policies --- Governance --- Governance Indicators --- Instrumental variables --- Linear regression --- Macroeconomics and Economic Growth --- Matrix --- Probabilities --- Probability --- Sample size --- Science and Technology Development --- Standard deviation --- Standard deviations --- Statistical & Mathematical Sciences --- Statistical significance
Listing 1 - 10 of 34 | << page >> |
Sort by
|