A researcher's decision about the sample to draw in a study may have an enormous impact on the results, and it rests on numerous statistical and practical considerations that can be difficult to juggle. Computer programs help, but no single software package exists that allows researchers to determine sample size across all statistical procedures. This pocket guide shows social work students, educators, and researchers how to prevent some of the mistakes that would result from a wrong sample size decision by describing and critiquing four main approaches to determining sample size. In concise, example-rich chapters, Dattalo covers sample-size determination using power analysis, confidence intervals, computer-intensive strategies, and ethical or cost considerations, as well as techniques for advanced and emerging statistical strategies such as structural equation modeling, multilevel analysis, repeated measures MANOVA and repeated measures ANOVA. He also offers strategies for mitigating pressures to increase sample size when doing so may not be feasible. Whether as an introduction to the process for students or as a refresher for experienced researchers, this practical guide is a perfect overview of a crucial but often overlooked step in empirical social work research.

This book addresses sample size and power in the context of research, offering valuable insights for graduate and doctoral students as well as researchers in any discipline where data is generated to investigate research questions. It explains how to enhance the authenticity of research by estimating the sample size and reporting the power of the tests used. Further, it discusses the issue of sample size determination in survey studies as well as in hypothesis testing experiments so that readers can grasp the concept of statistical errors, minimum detectable difference, effect size, one-tail and two-tail tests and the power of the test. The book also highlights the importance of fixing these boundary conditions in enhancing the authenticity of research findings and improving the chances of research papers being accepted by respected journals. Further, it explores the significance of sample size by showing the power achieved in selected doctoral studies. Procedure has been discussed to fix power in the hypothesis testing experiment. One should usually have power at least 0.8 in the study because having power less than this will have the issue of practical significance of findings. If the power in any study is less than 0.5 then it would be better to test the hypothesis by tossing a coin instead of organizing the experiment. It also discusses determining sample size and power using the freeware G*Power software, based on twenty-one examples using different analyses, like t-test, parametric and non-parametric correlations, multivariate regression, logistic regression, independent and repeated measures ANOVA, mixed design, MANOVA and chi-square.

A comprehensive approach to sample size determination and power with applications for a variety of fields Sample Size Determination and Power features a modern introduction to the applicability of sample size determination and provides a variety of discussions on broad topics including epidemiology, microarrays, survival analysis and reliability, design of experiments, regression, and confidence intervals. The book distinctively merges applications from numerous fields such as statistics, biostatistics, the health sciences, and engineering in order to provide a complete introduction to the general statistical use of sample size determination. Advanced topics including multivariate analysis, clinical trials, and quality improvement are addressed, and in addition, the book provides considerable guidance on available software for sample size determination. Written by a well-known author who has extensively class-tested the material, Sample Size Determination and Power: Highlights the applicability of sample size determination and provides extensive literature coverage Presents a modern, general approach to relevant software to guide sample size determination including CATD (computer-aided trial design) Addresses the use of sample size determination in grant proposals and provides up-to-date references for grant investigators An appealing reference book for scientific researchers in a variety of fields, such as statistics, biostatistics, the health sciences, mathematics, ecology, and geology, who use sampling and estimation methods in their work, Sample Size Determination and Power is also an ideal supplementary text for upper-level undergraduate and graduate-level courses in statistical sampling.

The Third Edition of this popular reference work describes the methods and rationale for sampling mosquitoes. Originally written by Professor M. W. Service, the book has been updated by John B Silver. More than 1,000 new references have been added and out-of-date material has been removed. The book emphasizes the ecology and behavior of those species that play a role as vectors of human and animal diseases and infections. Designed to serve as a practical reference for field entomologists and mosquito control specialists, it describes sampling methods and trapping technologies and tools for the collection of mosquitoes from egg to adult.

One of the most important problems in designing an experiment or a survey is sample size determination and this book presents the currently available methodology. It includes both random sampling from standard probability distributions and from finite populations. Also discussed is sample size determination for estimating parameters in a Bayesian setting by considering the posterior distribution of the parameter and specifying the necessary requirements. The determination of the sample size is considered for ranking and selection problems as well as for the design of clinical trials. Appropriate techniques for attacking the general question of sample size determination in problems of estimation, tests of hypotheses, selection, and clinical trial design are all presented, and will help the reader in formulating an appropriate problem of sample size and in obtaining the solution. The book can be used as a text in a senior-level or a graduate course on sample size methodology.Annotated list of tables in appendixSupplemental problems at the end of book

Understand a foundational area of experimental design with this innovative reference Animal-based research is an essential part of basic and preclinical research, but poses a unique set of experimental design challenges. The most important of these are the 3Rs Replacement, Reduction and Refinement the principles comprising the ethical framework for humane animal-based studies. However, many researchers have difficulty navigating the design trade-offs necessary to simultaneously minimize animal use, and produce scientific information that is both rigorous and reliable. A Guide to Sample Size for Animal-Based Studies meets this need with a thorough, accessible reference work to the subject. This book provides a straightforward systematic approach to "right-sizing" animal-based experiments, with sample size estimates based on the fundamentals of statistical thinking: structured research questions, variation control and appropriate design of experiments. The result is a much-needed guide to planning animal-based experiments to ensure scientifically valid and reliable results. This book offers: Step-by-step guidance in diverse methods for approximating and refining sample size Detailed treatment of research topics specific to animal-based research, including pilot, feasibility and proof-of-concept studies Sample size approximation methods for different types of data binary, continuous, ordinal, time to event and different study types description, comparison, nested designs, reference interval construction and dose-response studies Numerous worked examples, using real data from published papers, together with SAS and R code A Guide to Sample Size for Animal-Based Studies is a must-have reference for preclinical and veterinary researchers, as well as ethical oversight committees and policymakers.

Teach your students the most effective research strategies—including Internet surveys! Over the last few years changes in the marketing research process have been dramatic and far-reaching with the emergence of the Internet and other technologies. Marketing Research: Text and Cases, Second Edition, the completely updated edition of the classic Haworth textbook not only takes students step-by-step through cutting-edge design, conducting, and interpreting of market research, but is now updated to include Internet surveying. The topic of marketing research is comprehensively examined, including strategic and tactical decisions, choosing the proper research design, and successfully presenting results. The book provides clear explanations of complex issues and includes helpful charts, graphs, figures, sample questionnaires, and case studies which make important points easier to grasp. The practice cases (including an SPSS 11.0 data disk) offer engaging real-world problems that test the student’s research and analysis skills. Marketing Research: Text and Cases, Second Edition includes the updated and improved instructor’s manual, test bank, and PowerPoint slides. A brand-new section details procedures on how to successfully perform and effectively use Internet surveys, and includes a list of online survey providers, bulk email providers, and sample emails to use with online surveys. Stressing a practical, “hands on” project approach to learning, this guide not only prepares students for real-world experiences, but allows practitioners who are preparing market analysis reports needing background material to guide them through the process. Marketing Research: Text and Cases, Second Edition offers all the course-planning extras you need, including: thorough instructor’s manual sample syllabus research project tips, assignments, and forms test bank with true-false and multiple choice questions also available: 20-30 PowerPoint slides per chapter Marketing Research: Text and Cases, Second Edition gives instructors the tools they need for thorough course planning and is an ideal textbook for introductory marketing research courses and for practitioners looking for a guidebook.

This is a general and integrated introduction to qualitative and quantitative research design, data collection and analysis in the social sciences field and includes comprehensive and practical instruction (including screenshots) on the use of analysis software.

A researcher's decision about the sample to draw in a study may have an enormous impact on the results, and it rests on numerous statistical and practical considerations that can be difficult to juggle. Computer programs help, but no single software package exists that allows researchers to determine sample size across all statistical procedures. This pocket guide shows social work students, educators, and researchers how to prevent some of the mistakes that would result from a wrong sample size decision by describing and critiquing four main approaches to determining sample size. In concise, example-rich chapters, Dattalo covers sample-size determination using power analysis, confidence intervals, computer-intensive strategies, and ethical or cost considerations, as well as techniques for advanced and emerging statistical strategies such as structural equation modeling, multilevel analysis, repeated measures MANOVA and repeated measures ANOVA. He also offers strategies for mitigating pressures to increase sample size when doing so may not be feasible. Whether as an introduction to the process for students or as a refresher for experienced researchers, this practical guide is a perfect overview of a crucial but often overlooked step in empirical social work research.