Читать книгу Essentials of the California Verbal Learning Test - Thomas J. Farrer - Страница 10

The CVLT-II was the first major revision to the CVLT. The revision was guided by neuropsychological and cognitive research on memory, feedback from users and reviewers of the CVLT (both personal and published), and clinical experience by the authors. One of the major criticisms of the CVLT was the small, nonrepresentative sample used for the norms. Multiple studies demonstrated that the norms resulted in lower than expected scores in individuals with average to low educational attainment (Paolo, Troster, & Ryan, 1997; Wiens, Tindall, & Crossen, 1994). A large representative sample of the population aged 16–89 was collected to update the norms across seven age bands. In terms of content, the 16 items used in the word lists were modified to be easier to understand and were not presented as a shopping list. The word lists were derived using high-frequency words commonly spoken within the United States from four different semantic categories. The interference list also comprised 16 words from four categories, two of which overlapped with the original list. In addition, a forced-choice recognition trial was added to assess insufficient effort. Two new forms were also introduced with the CVLT-II: an Alternate Form and a Short Form. The Alternate Form is equated to the Standard Form, utilizes the same administration format, and provides the same scores as the Standard Form but uses alternate word lists from the Standard Form. The Short Form uses a nine-word list with a shortened format to accommodate use as a screener or with individuals that cannot tolerate lengthy testing. The Standard and Alternate Forms take 30 min to administer (in addition to the 20-min delay and an optional 10-min delay to administer the forced-choice recognition condition), whereas the Short Form takes around 20 min (in addition to the 10-min delay).

The development of the CVLT-II incorporated analysis of the performance of each score to evaluate the influence of demographic variables and general cognitive ability on performance, reliability and stability, score range and distribution for floor and ceiling problems, and clinical utility. Norms are corrected for age and sex because these demographic factors contributed more than 5% of the variance in primary scores. Detailed information on the psychometric properties and the clinical utility of the CVLT-II are described in the CVLT-II Manual (Delis, Kramer, Kaplan, & Ober, 2000).

Just as on the original CVLT, for the Standard and Alternate Forms, the examinee is read a list of 16 words across five learning trials, followed by an interference list trial. Following the interference trial, the examinee recalls the original list in both free-recall and cued-recall trials. The examiner then completes nonverbal testing for 20 min before administering delayed free-recall and cued-recall trials, as well as a delayed yes/no recognition trial. The examiner may then administer an optional forced-choice recognition trial following a 10-min delay (see Figure 1.2). All trials except the forced-choice recognition trial are required to derive the primary scores. It is highly recommended that examiners routinely administer the forced-choice recognition condition to assess performance validity.

For the Short Form, the examinee is read a list of nine words (from three semantic categories) across four learning trials, followed by a 30-s distractor task. Following the distraction task, the examinee is asked to recall the list in a short-delay free-recall trial. The examiner than completes nonverbal testing for 10 min before administering long-delay free- and cued-recall trials, as well as a delayed yes/no recognition trial. The examiner may then administer an optional forced-choice recognition trial following a 5-min delay (see Figure 1.3). All trials except the forced-choice recognition trial are required to derive the primary scores. See Rapid Reference 1.2 for an overview of differences between the Standard/Alternate Forms and the Short Form.

Learning trials	30-second distractor task	Short-delay	Long-delay (follows 10-min delay)	Yes/No recognition	Forced-choice recognition (follows a 5-min delay)
Trial 1 Free RecallTrial 2 Free RecallTrial 3 Free RecallTrial 4 Free Recall		Short-Delay Free Recall	Long-Delay Free RecallLong-Delay Cued Recall	Yes/No Recognition	Forced-Choice Recognition

Figure 1.2 CVLT-II and CVLT3 structure, brief form.