The international cognitive ability resource: Development and initial validation of a public-domain measure David M. Condon ⁎ ,1 , William Revelle Northwestern University, Evanston, IL, United States article info abstract Article history: Received 26 September 2013 Received in revised form 11 November 2013 Accepted 7 January 2014 Available online xxxx For all of its versatility and sophistication, the extant toolkit of cognitive ability measures lacks a public-domain method for large-scale, remote data collection. While the lack of copyright protection for such a measure poses a theoretical threat to test validity, the effective magnitude of this threat is unknown and can be offset by the use of modern test-development techniques. To the extent that validity can be maintained, the benefits of a public-domain resource are considerable for researchers, including: cost savings; greater control over test content; and the potential for more nuanced understanding of the correlational structure between constructs. The International Cognitive Ability Resource was developed to evaluate the prospects for such a public-domain measure and the psychometric properties of the first four item types were evaluated based on administrations to both an offline university sample and a large online sample. Concurrent and discriminative validity analyses suggest that the public-domain status of these item types did not compromise their validity despite administration to 97,000 participants. Further development and validation of extant and additional item types are recommended. © 2014 Elsevier Inc. All rights reserved. Keywords: Cognitive ability Intelligence Online assessment Psychometric validation Public-domain measures 1. Introduction The domain of cognitive ability assessment is now populated with dozens, possibly hundreds, of proprietary measures (Camara, Nathan, & Puente, 2000; Carroll, 1993; Cattell, 1943; Eliot & Smith, 1983; Goldstein & Beers, 2004; Murphy, Geisinger, Carlson, & Spies, 2011). While many of these are no longer maintained or administered, the variety of tests in active use remains quite broad, providing those who want to assess cognitive abilities with a large menu of options. In spite of this diversity, however, assessment challenges persist for researchers attempting to evaluate the structure and correlates of cognitive ability. We argue that it is possible to address these challenges through the use of well-established test development techniques and report on the development and validation of an item pool which demonstrates the utility of a public-domain measure of cognitive ability for basic intelligence research. We conclude by imploring other researchers to contribute to the on-going development, aggregation and maintenance of many more item types as part of a broader, public-domain tool — the International Cognitive Ability Resource (“ICAR”). 2. The case for a public domain measure To be clear, the science of intelligence has historically been well-served by commercial measures. Royalty income streams (or their prospect) have encouraged the develop- ment of testing “products” and have funded their ongoing production, distribution and maintenance for decades. These assessments are broadly marketed for use in educational, counseling and industrial contexts and their administration and interpretation are a core service for many applied psychologists. Their proprietary nature is fundamental to the perpetuation of these royalty streams and to the privileged status of trained psychologists. For industrial and Intelligence 43 (2014) 52–64 ⁎ Corresponding author at: Department of Psychology, Northwestern University, Evanston, IL 60208, United States. Tel.: +1 847 491 4515. E-mail address: davidcondon2009@u.northwestern.edu (D.M. Condon). 1 With thanks to Melissa Mitchell. 0160-2896/$ – see front matter © 2014 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.intell.2014.01.004 Contents lists available at ScienceDirect Intelligence journal homepage: