This book was developed to provide a “one-stop” resource for manycommon analyses that an applied researcher might complete when working with various instruments to measure educational and psychological traits. We have developed examples, collected our favorite examples and resources, and provided explanations of analyses in one easily digestible text. Many of the analyses presented assist in providing the recommended evidence to support the inferences drawn from scores from such instruments. That is, the results from applying these techniques assist providing score reliability and validity evidence.
Through our years as graduate students and the first segment of our academic lives, we have explored the use of various programs for scale development and the study of the psychometric properties of the scores to provide such evidence. We have had the experience, as I am sure many of you have had, of turning to multiple books for instructions and examples to complete analyses in the scale development and validation process. For those readers just beginning on the psychometric ride, you too will soon experience this. By no means will this book stop the need for multiple sources, in fact, that is always encouraged. However, this book should allow the reader to use this as a main guide and supplement to experience analyses described in major text books. Our examples are intended to be clear and concise with SPSS examples that can be easily adapted to fit many situations, as the reader learns and uses various techniques.
The anticipated audience for this book includes researchers, practitioners, and graduate students searching for a guide to perform common psychometric analyses on various types of assessment data. We assume a basic level of statistical knowledge but review concepts throughout. We envision that this text will (a) patiently wait on some office shelves begging to be handed to a student as a resource, (b) have a permanent home on desks where it continually rises to the top of the stacks for daily use of the applied researcher, (c) be happily carried in bags to and from work and class by the graduate student learning techniques, (d) be listed proudly as a reference text on syllabi, and finally (e) as an occasional drink coaster while deep thoughts are pondered about how to solve measurement problems. We hope that through such uses, particularly the latter, that we have provided some insight and assistance to the user in appropriately applying the techniques and concepts discussed.
We cover major topics such as item analysis, score reliability and validity, generalizability theory, differential item functioning, equating, and so on. Under each topic we present foundational ideas and give examples of how to apply these ideas immediately in ones work. Chapter 7, for instance, contains information on differential item functioning (DIF). We discuss DIF, its importance in the score validation process, and provide three techniques using SPSS to detect DIF, including how to handle clustered data in such analyses. The caveat is we do not provide a detailed discussion of each topic but rather the essence of each topic and several resources for additional reading. Again, we remind you that this is just one resource to promote your psychometric knowledge and practice.
We do assume the user has some basic knowledge and skill level in operating SPSS. At the same time, we do attempt to present material in a very understandable language avoiding or explaining jargon as we go. You may find the occasional joke thrown in from time to time to spice it up. But remember we are researchers, not comedians, even though students and family seem to laugh often at us for the things we think about! We do ask that if you have feedback, efficiency techniques, improvements, or just plain find mistakes to please notify us. We welcome user feedback and will incorporate this into a revision, if demanded by the reader!
So with that, let us get started on our SPSS adventure in applying psychometric techniques. In the words of Dr. Seuss, “Take it slowly. This book is dangerous.”
—W. Holmes Finch, Brian F. French,
and Jason C. Immekus,