Assessment of verbal ability, as may be indicated by vocabulary acquisition, is an important and (arguably) necessary part of any psychological, academic, speech-language, or neuropsychological evaluation, especially when learning issues are being investigated. Although measurement of vocabulary acquisition is relatively straightforward for native English speakers, there are several significant problems that must be overcome when attempting to do the same with English learners. Contemporary frameworks for evaluating general language development and verbal ability in English learners have been stymied by procedures that lack validity (e.g., testing of the limits, use of an interpreter/translator), nonverbal tests that intentionally avoid measuring aspects of language, a lack of tests in a language other than Spanish, and a paucity of bilingual evaluators with the requisite competency to conduct such evaluations. Even when the evaluator has such competency and a test is available in the examinee’s native language, the lack of attention to differences between bilingual and monolingual individuals, as well as differential exposure to the native language and English, has kept nearly all tests from reaching even the minimum level necessary to establish validity, let alone fairness in evaluations conducted for diagnostic purposes. When issues related to evaluation of individuals that span the entire school-based age range as well as applicability to English learners are added to the equation, practitioners quickly find themselves at a loss regarding measurement of language and language-related abilities in individuals from a wide range of cultural and linguistic backgrounds.
The Ortiz PVAT was designed specifically to take these issues into consideration and create a valid test of vocabulary acquisition applicable to virtually any English speaker or learner. The goal of developing a test that is appropriate for both native English speakers and for English learners required several structural features in its design.
First, a decision to use English as a common basis for assessment eliminated the need to create separate language tests. Second, the decision to use English only permitted the creation of a normative sample that could comprise English learners from any language background. Third, the creation of two distinct normative samples, along with the critical inclusion of English exposure as a stratification variable for English learners, provided the necessary true peer comparison groups that permit valid diagnostic comparisons of performance for either group. Although other tests have attempted to employ one or more of these strategies, only the Ortiz PVAT provides both English Speaker and English Learner normative samples. Moreover, because age and grade milestones are inappropriate benchmarks for English learners, incorporating English exposure with age represents a substantial shift in terms of establishing the level of adequate representation necessary to ensure valid and fair assessment of non-native English speakers with respect to vocabulary acquisition.
Not only is the Ortiz PVAT an innovative test of vocabulary acquisition for English speakers, it is also the first test that addresses one of the central questions in evaluation of diverse individuals often referred to as “difference vs. disorder” (i.e., whether an English learner’s low performance on an English language test is due to an inherent language disorder or simply the normal process of learning another language).
Beyond the unique features related to evaluation of English learners, in many ways the Ortiz PVAT represents a carefully constructed, theoretically based test that distinguishes itself even if it were only applicable to native English speakers. As noted previously, vocabulary acquisition is frequency based (Milton, 2009) and the Ortiz PVAT is no different than any other test in this regard. In addition to frequency, however, the Ortiz PVAT relies on the concepts of BICS and CALP (Cummins, 1984), which apply significantly to learning for both native English speakers and English learners. By distinguishing these levels of language development, results from the Ortiz PVAT become capable of discerning various levels of general development and proficiency, growth along these lines, and logical avenues for intervention that would otherwise not be identifiable. By linking assessment results with intervention and accommodating the need for repeated testing within a progress monitoring framework that evaluates an individual’s growth in vocabulary acquisition, the Ortiz PVAT gains substantial applicability and utility across a wide range of assessment and evaluation endeavors.