Trevor G. Bond - Applying the Rasch Model: Fundamental Measurement in the Human Sciences, Third Edition

Cited more than 1,900 times, this classic text facilitates a deep understanding of the Rasch model. The authors review the crucial properties of the model and demonstrate its use with a variety of examples from education, psychology, and health. A glossary and numerous illustrations aid the readers understanding. Readers learn how to apply Rasch analysis so they can perform their own analyses and interpret the results. The authors present an accessible overview that does not require a mathematical background.

Highlights of the new edition include:

• More learning tools to strengthen readers understanding, including chapter introductions, boldfaced key terms, chapter summaries, activities, and suggested readings.
• Divides chapters (4, 6, 7, and 8) into basic and extended understanding sections to allow readers to select the level most appropriate for their needs and to provide more in-depth investigations of key topics.
• A website at www.routledge.com/9780415833424 that features free Rasch software, data sets, an Invariance worksheet, detailed instructions for key analyses, and links to related sources.
• Greater emphasis on the role of Rasch measurement as a priori in the construction of scales and its use post hoc to reveal the extent to which interval scale measurement is instantiated in existing data sets.
• Emphasizes the importance of interval-level measurement data and demonstrates how Rasch measurement is used to examine measurement invariance.
• Insights from other Rasch scholars via innovative applications (Ch. 9).
• Extended discussion of invariance now reviews DIF, DPF, and anchoring (Ch. 5).
• Revised Rating Scale Model material now based on the analysis of the Childrens Empathic Attitudes Questionnaire (CEAQ; Ch. 6).
• Clarifies the relationships among Rasch measurement, True Score Theory, and Item Response Theory by reviewing their commonalities and differences (Ch. 13).
• Provides more detail on how to conduct a Rasch analysis so readers can use the techniques on their own (Appendix A).

This book is intended as a text for graduate courses in measurement, Item Response Theory, (advanced) research methods, or quantitative analysis taught in psychology, education, human development, business, and other social and health sciences. Professionals in these areas also appreciate the books accessible introduction.

Trevor G. Bond is Adjunct Professor at the College of Arts, Society and Education at James Cook University, Australia.

Christine M. Fox is Full Professor in Research and Measurement at the University of Toledo.

Third Edition

Third edition published 2015
by Routledge
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and by Routledge

27 Church Road, Hove, East Sussex BN3 2FA

Routledge is an imprint of the Taylor & Francis Group, an informa business

2015 Taylor & Francis

The right of Trevor G. Bond and Christine M. Fox to be identified as the authors of this work has been asserted by them in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988.

All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers.

Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe.

First edition published by Lawrence Erlbaum Associates, Inc. 2001

Second edition published by Routledge 2007

Library of Congress Cataloging-in-Publication Data

Bond, Trevor G.
Applying the Rasch model : fundamental measurement in the human sciences / authored by Trevor G. Bond and Christine M. Fox. Third edition.
pages cm
Includes bibliographical references and index.
1. PsychologyStatistical methods. 2. Social sciencesStatistical methods. 3. PsychologyResearchMethodology. 4. Social sciencesResearchMethodology. I. Fox, Christine M. II. Title.
BF39.B678 2015
150.72'7dc23 2014049808

ISBN: 978-0-415-83341-7 (hbk)

ISBN: 978-0-415-83342-4 (pbk)

ISBN: 978-1-315-81469-8 (ebk)

Typeset in Bembo

by Apex CoVantage, LLC

To Mike Linacre,
Cooperative, collegial, and collaborative.
TGB & CMF

It is not a mere coincidence that after my doctoral training in quantitative research methodology in Germany, I became more involved in Rasch measurement and that I met up with Trevor Bond while he was working in Hong Kong. Ironically, for me, the initial spark was the closing chapter A Synthetic Overview of the second edition of Bond & Fox, which contains a whole bunch of illustrative examples and explanations about the importance of measurement invariance. It was actually because of this chapter in particular that I decided to dig deeper into the subject of Rasch measurement. I do know that some of my colleagues turn up their noses at this less formalized introduction to Rasch measurement, and I do agree that, if one wants to gain an increasingly deeper understanding of the Rasch model, mathematical formalization is unavoidable. However, if Rasch experts cannot communicate even the most fundamental aspects of their best ideas to those who did not have the magical handshake of mathematics, their ideas are likely to be damned to remain as the secret knowledge of a kind of secret society. Fortunately, communicating the principles of Rasch measurement by revealing the underlying conceptual ideas and practical implications runs like a golden thread through this book.

So, back to the Hong Kong Institute of Education, November 2006: After assisting Trevor with the setup of a workshop on Rasch measurement, I sat down and listened to his introductory part. I already was quite versatile in Rasch measurement, its mathematical rationale, and the principle of specific objectivity of comparisons in particular, but the following line from Trevors talk was a flabbergasting eye-opener into the meaning of Rasch measurement: He asked, If all items of a test are supposed to measure the same thing, why should it then make a difference which items we use when comparing persons? In fact, I did know the mathematical principle of specific objectivity of comparisons between two arbitrarily chosen people, which can more formally expressed as follows:

Since, according to the equation of the Rasch model, the probability of solving an item depends only on the items difficulty and the persons ability, or the difference between the person parameter and item parameter, it is possible to calculate the difference in solving probability of a person j and j as the difference between the person abilities: ji (ji) = jj, (with i: item difficulty parameter of an item i, and j: person parameter of a person j). A comparison of persons is therefore equal to the difference between their positions on the latent dimension. This is independent of the item i that has been used for the comparison.