ADVISING ON RESEARCH METHODS
SELECTED TOPICS 2011

Advising on research methods

Selected topics 2011

Edited by

Herman J. Adèr and Gideon J. Mellenbergh

Johannes van Kessel Publishing
Huizen, The Netherlands

© Herman J. Adèr and Gideon J. Mellenbergh 2011

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, transmitted or utilized in any form or by any means, electoronic, mechanical, photocopying, recording or otherwise, without permission in writing from the Publisher.

Huizen, The Netherlands
E-mail: Publishing@jvank.nl

ISBN 978-90-79418-16-9

NUR: 840, General Education

Preface

This book results from the research master course Methodological Advice (Department of Psychology, University of Amsterdam) that was given in the fall of 2011. The objectives of this course are (1) to acquire methodological knowledge that is needed for advising researchers in the behavioral and social sciences, and (2) to get experience with methodological consultancy. The students get assignments, among others, to write a paper on a topic that occurs in methodological consultancy.

Each of the students selects a topic from a list of topics. The student who selected the topic is the first author of a paper on that topic, and he or she is assisted by a co-author (one of the other students of the course). The authors are instructed to write an article that will be published in a book. The intended audience of the book are fellow research master students who give methodological advice on research in the behavioral and social sciences, such as is done in methodology shops of Dutch psychology departments. The procedure to prepare the book is similar to the procedure that is used to prepare an edited book. The authors write a first draft of the article, the first draft is reviewed by the other students and the two course instructors, and the authors rewrite the first draft.

Six students participated in the course. They made the following contributions to the book:

Anja Sommavilla and Corinne Brenner

discuss the pathway of going from a substantive research question to a statistical model. They show how a substantive question is transformed into a graphical representation, and how this representation is transformed into a statistical model.

Corinne Brenner and Charlotte M. W. Gaasterland

discuss Internet
sampling methods. They describe advantages and disadvantages of Internet sampling, and they mention payoffs of this data collection method.

César-Reyer Vroom and Daniel A. Bannan

discuss Computerized Adaptive Testing (CAT). They give an introduction into Item Response Theory (IRT), and they describe how IRT models are applied in CAT.

Daniel A. Bannan and César-Reyer Vroom

discuss stepwise model selection methods in regression analysis. They identify pitfalls of stepwise model selection, and they mention methods to avoid them.

Charlotte M. W. Gaasterland and Mattis van den Bergh

give an introduction into survival analysis. They describe the situations where survival analysis can be applied, and they explain how it can be implemented in SPSS.

Mattis van den Bergh and Anja Sommavilla

discuss mixed
methods designs that combine quantitative and qualitative research methods. They give reasons for the use of mixed methods designs, and they describe different types of these designs.

The authors worked under great time pressure because the whole procedure of writing, reviewing, and rewriting had to be done within one month. Nevertheless, they managed to produce good and interesting contributions, and to meet the deadline.

We thank them for their enthusiasm, competence, and working speed. Moreover, we thank Johannes van Kessel Publishing for publishing this book, and for producing it within fourteen days. We think that this book is useful for methodological advisors, and we hope that it will be used in methodological consultancy.

Amsterdam, December 8, 2011

Gideon J. Mellenbergh
Herman J. Adèr
(course instructors)

About the authors

Herman Adèr

studied Mathematics and Psychological Methods at the University of Amsterdam. His PhD thesis was on the representation of Methodological Knowledge. He has been a statistical/methodological consultant for many years and has continued to be so after his retirement from VU University Amsterdam in 2005. With Gideon Mellenbergh, he has given courses ‘Advising on research methods’ since 2000.

Daniel Bannan

obtained a Bachelor’s degree in Forensic Psychology from Leeds Trinity University College. During this time Daniel also worked alongside West Yorkshire Police’s Offender Management and Homicide and Major Enquiry teams. Daniel currently works within the Methodological Department at the University of Amsterdam in an advisory capacity and is studying towards his Research Masters in Psychology.

Daniel’s interests lie within the study of Terrorism and he is currently researching inter-group Humiliation and Radicalisation.

Mattis van den Bergh

has a Bachelor’s degree in Psychological Methods. He is a first year student of the Research Master of Psychology. He has over four years of experience with research by working as a Research Assistent at the University of Utrecht and the University of Amsterdam. He has experience with Methodological Consulting by working in the Methodology shop of the University of Amsterdam which he currently chairs.

Corinne Brenner

is originally from the U.S. She received her Bachelor’s degree in Psychology from Cornell University in 2008. She is a second year student in the Research Master program, studying Social Psychology and Research Methods.

Charlotte Gaasterland

started with a Bachelor’s degree in Psychobiology, which she received in 2010. In her second year she decided to start the Bachelor of Psychology as well which she received in 2011. She is now a first year student in the Research Master program, with a major in Psychological Methods. Her main interests are in Methodology and Sexology which she plans to do as a minor in the Research Master.

Anja Sommavilla

grew up in Munich, Germany, but moved to Vienna after her High school graduation in 2008 for a Vordiplom in Psychology at the University of Vienna. Currently she is a Psychology Research Master student at the University of Amsterdam, majoring in Psychological Methods. Her interests are, among others, Structural Equation modelling (SEM), Measurement theory, Philosophy of mind and the theoretical foundations of Psychometric Models.

Gideon Mellenbergh

is emeritus professor of Psychological Methods at the Department of Psychology, University of Amsterdam. His research has been on different topics of Psychometrics: construction of educational and psychological tests, psychometric decision making, differential item functioning, and the conceptual analysis of psychometric models. He has a long-standing experience in methodological consultancy in different fields.

César-Reyer Vroom

is a Psychology Research Master student at the University of Amsterdam. After obtaining his bachelor’s degree in Psychonomics he started the Research Master. After the first year of his master’s he took a year off from the standard program and devoted himself to obtaining more knowledge of Psychological Methods and Statistics. After he has finalized his research master, he wants to do a PhD ideally combining Brain and Cognition and Psychological Methods and Statistics. His main topics of interest are in consciousness and decision making.