Cross-battery assessment is the process by which psychologists use information from multiple test batteries (i.e., various IQ tests) to help guide diagnostic decisions and to gain a fuller picture of an individual's cognitive abilities than can be ascertained through the use of single-battery assessments. The cross-battery approach (XBA) was first introduced in the late 1990s by Dawn Flanagan, Samuel Ortiz and Kevin McGrew. It offers practitioners the means to make systematic, valid and up-to-date interpretations of intelligence batteries and to augment them with other tests in a way that is consistent with the empirically supported Cattell–Horn–Carroll (CHC) theory of cognitive abilities.
Three Foundational Sources of Information
The XBA approach is a time efficient method to reliably measure a wider (or more in-depth but selective range) of cognitive abilities/processes than any single intelligence battery can measure. It is based on three foundational sources of information (i.e., practice, research and test development) that provide the knowledge necessary to organise theory-driven, comprehensive, reliable, and valid assessments of cognitive abilities.
Practice
R. W. Woodcock conducted a joint factor analysis suggesting the necessity of cross-battery assessments to measure a broad range of cognitive abilities rather than a single intellectual battery. For instance, he found that of the major intellectual batteries utilized prior to 2000, most failed to measure three or more broad CHC abilities that were considered essential in understanding and predicting school achievement. This provided the impetus for developing the XBA approach. The XBA approach also helps facilitate communication among professionals, which guards against misinterpretation. The XBA approach offers practitioners a psychometrically defensible way of identifying normative strengths and weaknesses in cognitive abilities.
Research
The XBA approach helped to promote a greater understanding between cognitive abilities and important outcome criteria. Furthermore, improving the validity of CHC ability measures will further elucidate the relations between CHC cognitive abilities and different outcomes, such as achievement and occupational outcomes.
Test Development
Test authors have utilized CHC theory and XBA CHC test classifications as a blueprint for test development (WJ III, SB5, KABC-II, and DAS-II etc.). Despite the fact that cognitive abilities tests demonstrate a greater coverage of CHC broad cognitive abilities now as compared to previous years; there is still a need to use XBA approach for assessment.
Application of the XBA Approach
It is recommended that practitioners adhere to several guiding principles in order to ensure that XBA procedures are psychometrically and theoretically sound. First, one should select an intelligence battery that best addresses referral concerns. Second, subtests and clusters or composites from a single battery should be utilized whenever possible in order to best represent the broad CHC abilities (i.e., use actual norms whenever possible). Third, it is important to construct CHC broad and narrow ability clusters through acceptable methods, such as CHC theory driven factor analyses or expert consensus content-validity studies. Fourth, when two or more qualitatively different indicators of a broad abilities of interest are not assessed or available on the core battery, then one may supplement it for broad ability indicators from another battery. Finally, when crossing batteries, select tests that were developed and normed within a few years of one another. Sixth, in order to minimize the effect of spurious differences between test scores, select tests from the smallest number of batteries. Evaluation requires professional judgement and should include direct observations, including interviews with those who know the test subject. Sound decisions require an explanatory framework that is logical and consistent, with an explanation for any conflicting data.
Implementation of the XBA Approach Step-by-Step
Select primary intelligence battery for assessment
Identify represented CHC abilities
Select tests to measure CHC abilities not measured by the primary battery
Administer the primary battery (and any other supplemental tests) Enter data into the XBA DMIA (provided in "Essentials of Cross Battery Assessment: Second Edition" Follow XBA guidelines