Internal and External Validity of Research Designs
Internal and External Validity of Research Designs
1. (300 words) Compare and contrast internal and external validity of research designs.
2. (300 words) What is the pros and cons to internal and external validity of research designs.
3. (300 words) How can internal and external validity of research designs benefit evidence base practice and the healthcare industry?
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4. (500 words) Find a study evidence base practice study related to the PICOT question below, and examine it to see which of the threats to internal and external validity is present in that study and why?
Use APA 7th edition and at least four reference including the text book.
For immobile post-surgical client who are at an increased risk for deep venous thrombosis (P) how effective is the application of sequential compression devices (SCDs) (I) in comparison to leg exercises (C) in reducing the prevalence of deep vein thrombosis (O) within one month time (T)?
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Library of Congress Cataloging-in-Publication Data
Names: Polit, Denise F., author. | Beck, Cheryl Tatano, author. Title: Essentials of nursing research : appraising evidence for nursing practice / Denise
F. Polit, Cheryl Tatano Beck. Description: Ninth edition. | Philadelphia : Wolters Kluwer Health,  | Includes
bibliographical references and index. Identifiers: LCCN 2016043994 | ISBN 9781496351296 Subjects: | MESH: Nursing Research | Evidence-Based Nursing Classification: LCC RT81.5 | NLM WY 20.5 | DDC 610.73072—dc23 LC record available at https://lccn.loc.gov/2016043994
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ABOUT THE AUTHORS
Denise F. Polit, PhD, FAAN, is an American health care researcher who is recognized internationally as an authority on research methods, statistics, and measurement. She received her Bachelor’s degree from Wellesley College and her Ph.D. from Boston College. She is the president of a research consulting company, Humanalysis, Inc., in Saratoga Springs, New York, and professor at Griffith University, Brisbane, Australia. She has published in numerous journals and has written several award-winning textbooks. She has recently written a ground-breaking book on measurement in health, Measurement and the Measurement of Change: A Primer for the Health Professions. Her research methods books with Dr. Cheryl Beck have been translated into French, Spanish, Portuguese, German, Chinese, and Japanese. She has been invited to give lectures and presentations in many countries, including Australia, India, Ireland, Denmark, Norway, South Africa, Turkey, Sweden, and the Philippines. Denise has lived in Saratoga Springs for 29 years and is active in the community. She has assisted numerous nonprofit organizations in designing surveys and analyzing survey data. Currently, she serves on the board of directors of the YMCA, Opera Saratoga, and the Saratoga Foundation. Internal and External Validity of Research Designs
Cheryl Tatano Beck, DNSc, CNM, FAAN, is a distinguished professor at the University of Connecticut, School of Nursing, with a joint appointment in the Department of Obstetrics and Gynecology at the School of Medicine. She received her master’s degree in maternal–newborn nursing from Yale University and her doctor of nursing science degree from Boston University. She has received numerous awards such as the Association of Women’s Health, Obstetric and Neonatal Nursing’s Distinguished Professional Service Award, Eastern Nursing Research Society’s Distinguished Researcher Award, the Distinguished Alumna Award from Yale University School of Nursing, and the Connecticut Nurses’ Association’s Diamond Jubilee Award for her contribution to nursing research. Over the past 30 years, Cheryl has focused her research efforts on developing a research program on postpartum mood and anxiety disorders. Based on the findings from her series of qualitative studies, Cheryl developed the Postpartum Depression Screening Scale (PDSS), which is published by Western Psychological Services. She is a prolific writer who has published over 150 journal articles. In addition to co-authoring award-winning research methods books with Denise Polit, Cheryl coauthored with Dr. Jeanne Driscoll Postpartum Mood and Anxiety Disorders: A Clinician’s Guide, which received the 2006 American Journal of Nursing Book of the Year Award. In addition, Cheryl has published two other books: Traumatic Childbirth and Routledge International Handbook of Qualitative Nursing Research. Her most recent book is Developing a Program of Research in Nursing.
Essentials of Nursing Research, ninth edition, helps students learn how to read and critique research reports and to develop an appreciation of research as a path to enhancing nursing practice.
We continue to enjoy updating this book with important innovations in research methods and with nurse researchers’ use of emerging methods. Feedback from our loyal adopters has inspired several important changes to the content and organization. We are convinced that these revisions introduce important improvements—while retaining many features that have made this book a classic best-selling textbook throughout the world. The ninth edition of this book, its study guide, and its online resources will make it easier and more satisfying for nurses to pursue a professional pathway that incorporates thoughtful appraisals of evidence.
LEGACY OF ESSENTIALS OF NURSING RESEARCH This edition, like its predecessors, is focused on the art—and science—of research critique. The textbook offers guidance to students who are learning to appraise research reports and use research findings in practice.
Among the basic principles that helped to shape this and earlier editions of this book are as follows:
1. An assumption that competence in doing and appraising research is critical to the nursing profession
2. A conviction that research inquiry is intellectually and professionally rewarding to nurses
3. An unswerving belief that learning about research methods need be neither intimidating nor dull
Consistent with these principles, we have tried to present research fundamentals in a way that both facilitates understanding and arouses curiosity and interest.
NEW TO THIS EDITION
In the previous edition, we separated chapters on quantitative and qualitative designs and methods into two separate parts. In this edition, we organized the parts by methodologic content. So, for example, Part 3 in this edition covers designs and methods for quantitative, qualitative, and mixed methods research, and Part 4 is devoted to analysis and interpretation in quantitative and qualitative studies. (Please see “The Text” later in this preface for more information.) We think this new organization offers greater continuity of methodologic concepts and will facilitate better understanding of key methodologic differences between quantitative and qualitative research. We are confident that this new organization will better meet the needs of students and faculty.
Manageable Text for One-Semester Course We have streamlined the text to make it more manageable for use in a one-semester course. We reduced the length by organizing content differently and by keeping essential information in the text while moving background/advanced content online, making this an 18-chapter book rather than the previous 19 chapters in the eighth edition.
Enhanced Accessibility To make this edition even more user-friendly than in the past, we have made a concerted effort to simplify the presentation of complex topics. Most importantly, we have reduced and simplified the coverage of statistical information. We eliminated the chapter on measurement, opting to present a shorter, more digestible section on this topic in our chapter on quantitative data collection, which is supplemented by information in the chapter on statistical analysis. In addition, throughout the book we have used more straightforward, concise language. Internal and External Validity of Research Designs
New Content In addition to updating the book with new information on conventional research methods, we have added content on the following topics:
Quality improvement projects, describing how they are distinct from research studies and evidence-based practice (EBP) projects. This new content is found in Chapter 13.
Clinical significance, a seldom-mentioned but important topic that has gained prominence among researchers in other health care fields but has only recently gained traction among nurse researchers. This new content is found in Chapter 15.
THE TEXT The content of this edition is as follows:
Part 1, Overview of Nursing Research and Its Role in Evidence-Based Practice,
introduces fundamental concepts in nursing research. Chapter 1 summarizes the background of nursing research, discusses the philosophical underpinnings of qualitative research versus quantitative research, and describes major purposes of nursing research. Chapter 2 offers guidance on using research to build an evidence- based practice. Chapter 3 introduces readers to key research terms and presents an overview of steps in the research process for both quantitative and qualitative studies. Chapter 4 focuses on research journal articles, explaining what they are and how to read them. Chapter 5 discusses ethics in nursing studies.
Part 2, Preliminary Steps in Quantitative and Qualitative Research, further sets the stage for learning about the research process by considering aspects of a study’s conceptualization. Chapter 6 focuses on the development of research questions and the formulation of research hypotheses. Chapter 7 discusses how to retrieve research evidence (especially in electronic bibliographic databases) and the role of research literature reviews. Chapter 8 presents information about theoretical and conceptual frameworks.
Part 3, Designs and Methods for Quantitative and Qualitative Nursing Research, presents material on the design and conduct of all types of nursing studies. Chapter 9 describes fundamental design principles and discusses many specific aspects of quantitative research design, including efforts to enhance rigor. Chapter 10 introduces the topics of sampling and data collection in quantitative studies. Concepts relating to quality in measurements—reliability and validity—are introduced in this chapter. Chapter 11 describes the various qualitative research traditions that have contributed to the growth of constructivist inquiry and presents the basics of qualitative design. Chapter 12 covers sampling and data collection methods used in qualitative research, describing how these differ from approaches used in quantitative studies. Chapter 13 emphasizes mixed methods research, but the chapter also discusses other special types of research such as surveys, outcomes research, and quality improvement projects.
Part 4, Analysis and Interpretation in Quantitative and Qualitative Research, presents tools for making sense of research data. Chapter 14 reviews methods of statistical analysis. The chapter assumes no prior instruction in statistics and focuses primarily on helping readers to understand why statistics are useful, what test might be appropriate in a given situation, and what statistical information in a research article means. Chapter 15 discusses approaches to interpreting statistical results, including interpretations linked to assessments of clinical significance. Chapter 16 discusses qualitative analysis, with an emphasis on ethnographic, phenomenologic, and grounded theory studies. Chapter 17 elaborates on criteria for appraising trustworthiness and integrity in qualitative studies. Finally, Chapter 18 describes systematic reviews, including how to understand and appraise both meta-analyses and metasyntheses. Internal and External Validity of Research Designs
At the end of the book, we offer students additional critiquing support. In the appendices, we offer full-length research articles —two quantitative, one qualitative, and one mixed methods—that students can read, analyze, and critique. Students can model their critiques on the full critiques of two of those studies provided or compare their work to the ones provided. A glossary at the end of the book provides additional support for those needing to look up the meaning of a methodologic term.
FEATURES OF THE TEXT We have retained many of the classic features that were successfully used in previous editions to assist those learning to read and apply evidence from nursing research:
Clear, User-Friendly Style. Our writing style is easily digestible and nonintimidating —and we have worked even harder in this edition to write clearly and simply. Concepts are introduced carefully, difficult ideas are presented thoughtfully, and readers are assumed to have no prior knowledge of technical terms.
Critiquing Guidelines. Each chapter includes guidelines for conducting a critique of various aspects of a research report. The guidelines sections provide a list of questions that walk students through a study, drawing attention to aspects of the study that are amenable to appraisal by research consumers. Internal and External Validity of Research Designs
Research Examples and Critical Thinking Exercises. Each chapter concludes with one or two actual research examples designed to highlight critical points made in the chapter and to sharpen the reader’s critical thinking skills. In addition, many research examples are used to illustrate key points in the text and to stimulate students’ thinking about areas of research inquiry. We have chosen many international examples to communicate to students that nursing research is growing in importance worldwide. Some of the Critical Thinking Exercises focus on the full-length articles in Appendix A (a quantitative study) and Appendix B (a qualitative study).
Tips for Students. The textbook is filled with practical guidance and tips on how to translate the abstract notions of research methods into more concrete applications. In these tips, we have paid special attention to helping students read research reports, which are often daunting to those without specialized research training.
Graphics. Colorful graphics—in the form of supportive tables, figures, and examples —reinforce the text and offer visual stimulation.
Chapter Objectives. Learning objectives are identified in the chapter opener to focus students’ attention on critical content.
Key Terms. Each chapter opener includes a list of new terms, and we have made the list more focused and less daunting by including only key new terms. In the text, new terms are defined in context (and bolded) when used for the first time; terms of lesser
importance are italicized. Key terms are also defined in our glossary.
Bulleted Summary Points. A succinct list of summary points that focus on salient chapter content is provided at the end of each chapter.
Essentials of Nursing Research: Appraising Evidence for Nursing Practice, ninth edition, has ancillary resources designed with both students and instructors in mind, available on website.
Student Resources Available on Supplements for Each Chapter further students’ exploration of specific topics. A full
list of the Supplements appears on page xxii. These supplements can be assigned to provide additional background or to offer advanced material to meet students’ specific needs.
Interactive Critical Thinking Activity brings the Critical Thinking Exercises from the textbook (except those focused on studies in the appendices) to an easy-to-use interactive tool that enables students to apply new skills that they learn in each chapter. Students are guided through appraisals of real research examples and then ushered through a series of questions that challenge them to think about the quality of evidence from the study. Responses can be printed or e-mailed directly to instructors for homework or testing.
Hundreds of Student Review Questions help students to identify areas of strength and areas needing further study.
Answers to Critical Thinking Exercises are provided for questions related to the studies in Appendices A and B of the textbook.
Journal Articles—18 full articles from Wolters Kluwer journals (one corresponding to each chapter)—are provided for additional critiquing opportunities. Many of these are the full journal articles for studies used as the end-of-chapter Research Examples. All journal articles that appear on are identified in the text with and are called out in the References lists for appropriate chapters with a double asterisk (**).
Internet Resources with relevant and useful websites related to chapter content can be clicked on directly without having to retype the URL and risk a typographical error. This edition also includes links to all open-access articles cited in the textbook; these articles are called out in the References lists for appropriate chapters with a single asterisk (*).
Critiquing Guidelines and Learning Objectives from the textbook are available in Microsoft Word for your convenience.
Nursing Professionals Roles and Responsibilities.
Instructor’s Resources Available on NEW! Test Generator Questions are completely new and written by the book’s
authors for the ninth edition. Hundreds of multiple-choice questions aid instructors in assessing their students’ understanding of the chapter content.
An Instructor’s Manual includes a preface that offers guidance to improve the teaching experience. We have recognized the need for strong support for instructors in teaching a course that can be quite challenging. Part of the difficulty stems from students’ anxiety about the course content and their concern that research methods might not be relevant to their nursing practice. We offer numerous suggestions on how to make learning about—and teaching—research methods more rewarding. The contents of the Instructor’s Manual include the following for each chapter:
Statement of Intent. Discover the authors’ goals for each chapter. Special Class Projects. Find numerous ideas for interesting and meaningful class
projects. Check out the icebreakers and activities relating to the Great Cookie Experiment with accompanying SPSS files.
Test Questions and Answers. True/false questions, plus important application questions, test students’ comprehension and their ability to put their new critiquing skills to use. The application questions focus on a brief summary of a study and include several short-answer questions (with our answers), plus essay questions. These application questions are intended to assess students’ knowledge
about methodologic concepts and their critiquing skills.
Answers to the Interactive Critical Thinking Activity. Suggested answers to the questions in the Interactive Critical Thinking Activity are available to instructors. Students can either print or e-mail their responses directly to the instructor for testing or as a homework assignment.
Two sets of PowerPoint Slides: “Test Yourself!” PowerPoint Slides. For each chapter, a slide set of five
multiple-choice “Test Yourself!” questions relating to key concepts in the chapter are followed by answers to the questions. The aim of these slides is not to evaluate student performance. We recommend these slides be given to students for self- testing, or they can be used in the classroom with i>clickers to assess students’ grasp of important concepts. To enhance the likelihood that students will see the relevance of the concepts to clinical practice, all the questions are application-type questions. We hope instructors will use the slides to clarify any misunderstandings and, just as importantly, to reward students with immediate positive feedback about newly acquired skills.
PowerPoint Presentations offer traditional summaries of key points in each chapter for use in class presentations. These slides are available in a format that permits easy adaptation and also include audience response questions that can be used on their own or are compatible with i>clicker and other audience response programs and devices.
An Image Bank includes figures from the text.
QSEN Map shows how the book content integrates QSEN competencies.
BSN Essentials Competencies Map shows how the book content integrates American Association of Colleges of Nursing (AACN) Essentials of Baccalaureate Education for Professional Nursing Practice competencies.
Strategies for Effective Teaching offer creative approaches for engaging students.
Learning Management System Course Cartridges.
Access to all student resources previously discussed.
STUDY GUIDE The accompanying Study Guide for Essentials of Nursing Research, ninth edition, is available for purchase and augments the text, providing students with opportunities to apply their learning.
Critiquing opportunities abound in the Study Guide, which includes eight research articles in their entirety. The studies represent a range of nursing topics and research approaches, including a randomized controlled trial, a correlational/mixed
methods study, an EBP project, three qualitative studies (ethnographic, phenomenologic, and grounded theory), a meta-analysis, and a metasynthesis. The Application Exercises in each chapter guide students in reading, understanding, and critiquing these eight studies. Internal and External Validity of Research Designs
Answers to the “Questions of Fact” section in the Application Exercises in each chapter are presented in Appendix I of the Study Guide so that students can get immediate feedback about their responses.
Although critiquing skills are emphasized in the Study Guide, other included activities support students’ learning of fundamental research terms and principles, such as fill- in-the-blank exercises, matching exercises, and focused Study Questions. Answers to those questions that have an objective answer are provided in Appendix I.