Research Methods And Statistics: A Critical Thinking Approach

THIRD EDITION Research Methods and Statistics A Critical Thinking Approach Sherri L. Jackson Jacksonville University Australia • Brazil • Japan • Korea • Mexico • Singapore • Spain • United Kingdom • United States Research Methods and Statistics: A Critical Thinking Approach, Third Edition Sherri L. Jackson Psychology Editor: Erik Evans Assistant Editor: Rebecca Rosenberg Editorial Assistant: Ryan Patrick Technology Project Manager: Lauren Keyes Marketing Manager: Michelle Williams © 2009, 2006 Wadsworth, Cengage Learning ALL RIGHTS RESERVED. No part of this work covered by the copyright herein may be reproduced, transmitted, stored, or used in any form or by any means graphic, electronic, or mechanical, including but not limited to photocopying, recording, scanning, digitizing, taping, Web distribution, information networks, or information storage and retrieval systems, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the publisher. Marketing Assistant: Melanie Creggar Marketing Communications Manager: Linda Yip Project Manager, Editorial Production: Tanya Nigh Creative Director: Rob Hugel For product information and technology assistance, contact us at Cengage Learning Customer & Sales Support, 1-800-354-9706 For permission to use material from this text or product, submit all requests online at cengage.com/permissions Further permissions questions can be e-mailed to [email protected] Art Director: Vernon Boes Print Buyer: Paula Vang Permissions Editor: Bob Kauser Production Service: Macmillan Publishing Solutions Text Designer: Anne Draus, Scratchgravel Publishing Services Copy Editor: Julie Macnamee Cover Designer: William Stanton Library of Congress Control Number: 2008920909 ISBN-13: 978-0-495-51001-7 ISBN-10: 0-495-51001-7 Wadsworth 10 Davis Drive Belmont, CA 94002-3098 USA Cover Image: David McGlynn/Getty Images Compositor: Macmillan Publishing Solutions Cengage Learning is a leading provider of customized learning solutions with office locations around the globe, including Singapore, the United Kingdom, Australia, Mexico, Brazil, and Japan. Locate your local office at international.cengage.com/region Cengage Learning products are represented in Canada by Nelson Education, Ltd. For your course and learning solutions, visit academic.cengage.com Purchase any of our products at your local college store or at our preferred online store www.ichapters.com Printed in the United States of America 1 2 3 4 5 6 7 12 11 10 09 08 To Rich About the Author Sherri L. Jackson is Professor of Psychology at Jacksonville University, where she has taught since 1988. At JU, she has won Excellence in Scholarship and University Service Awards, the university-wide Professor of the Year Award in 2004, the Woman of the Year Award in 2005, and the Institutional Excellence Award in 2007. She received her M.S. and Ph.D. in cognitive/experimental psycho