The “New Psychometrics” – Item ResponseTheory

Classical test theory is concerned with the reliability of a test and assumes that the items

within the test are sampled at random from a domain of relevant items. Reliability is seen

as a characteristic of the test and of the variance of the trait it measures. Items are treated

as random replicates of each other and their characteristics, if examined at all, are expressed

as correlations with total test score or as factor loadings on the putative latent variable(s) of

interest. Characteristics of their properties are not analyzed in detail. This led Mellenbergh

(1996) to the distinction between theories of tests (Lord and Novick, 1968) and a theories

of items (Lord, 1952; Rasch, 1960). The so-called “New Psychometrics” (Embretson and

Hershberger, 1999; Embretson and Reise, 2000; Van der Linden and Hambleton, 1997) is a

theory of how people respond to items and is known as Item Response Theory or IRT. Over

the past twenty years there has been explosive growth in programs that can do IRT, and

within R there are at least four very powerful packages: eRm (Mair and Hatzinger, 2007),

ltm Rizopoulos(2006), lme4 (Doran et al., 2007) and MiscPsycho, (Doran, 2010). Additional

packages include mokken (van der Ark, 2010) to do non-metric IRT and plink (Weeks, 2010)

to link multiple groups together. More IRT packages are being added all of the time.

Topics covered:

Chapter 8 - The “New Psychometrics” – Item ResponseTheory

Chapter 9 - Validity

Chapter 10 - Reliability + Validity = Structural Equation Models

Source link - http://bit.ly/1hJT9FL

Use Wikipedia as your Review Material for Psychometrician Licensure Exam

(Image Source - http://us.123rf.com/450wm/radiantskies/radiantskies1301/radiantskies130101036/17197657-abstract-word-cloud-for-validity-with-related-tags-and-terms.jpg)

Wikipedia is definitely the most accessible source of information too many of us with internet connection. Who needs books and text book anyway? But of course the academe will frown on you if you would insist on using wikipedia alone and not the scientific canon! So for psychometrician licensure exam reviewers, to resolve such issue, it is always good to check and refer back to your text books.  Make sure though that you also get the latest  text book at least published 3-5 years back. Psychology is a dynamic field of study that continue to evolve with the latest discoveries and scientific researches.

This is where wikipedia comes handy, the content is updated instantaneously, unlike books that will take time to get revised, but now online versions of text books  (e-books) are also now available and you can get updated version from the sites of the publishers, well the disadvantage of course is the costs.

Just to cite an example, in college in the 1990s, 2-3 decades ago, validity has a different meaning with what has evolved in late 20th century (makes me feel so ancient like a dinosaur). So there is now a different reinterpretation of test validity: a traditional view/classical models and current view/modern models  for validity as it is used and understood in psychological testing.

So compare Test Validity on:

• wikipedia - http://en.wikipedia.org/wiki/Test_validity

• with what is on your textbook - (? year)

• and that of a later  version of textbook say by Miller, McIntire, Lovler (2011), citing  the studies of Brennan, Kane, Goodwin and Leech among others.

• or even a powerpoint presentation Psychometric Principles by Professor John Rust Powerpoint Presentation for the Summer School 2009, Professor John Rust, University of Cambridge  http://psychometricpinas.blogspot.com/2014/01/psychometric-principles-by-professor.html 

• well even the text book by Philippine authors Munarriz and Cervera (2013) still discussed the classical model on test validity.

But then again it is good to know both models, the old and the new and application-wise we would know better which should prevail and more appropriate as concept and in our practice.

So my advise, maximize your internet access and read/review using wikipedia, but double check and refer back to your text book and make sure you get to compare it with a later edition. Supplement your readings with what other materials you can find online from the website of psych organizations (PAP, APA, etc), free online journals, scientific articles, and of course this blog, and even facebook, etc.

And to have some focus on what to read and review refer to this older blog post -
http://psychometricpinas.blogspot.com/p/chedcourse-specification.html


Happy reviewing!

Share your review strategies and materials as well!