It measures episodic verbal learning and memory, and demonstrates sensitivity to a range of clinical conditions.
The CVLT indexes free and cued recall, serial position effects (including primacy and recency), semantic clustering, intrusions, interference and recognition.
The California Verbal Learning Test-II (CVLT-II) is an updated version of the original CVLT, which has been standardized and provides normative data.
Raw scores are used for all analyses, ultimately determining how many errors are made in each learning task.
[2] It is suggested that a general verbal learning component consistently accounts for about 35-40% of the total variance and consists of total free recall over the five trials of list A, semantic clustering free and cued recall (both short- and long-delays), and recognition hits.
Studies have demonstrated that inconsistent recall across trials characterises patients with amnesia caused by frontal lobe pathology.
[21] The construct validity makes it a measure of episodic verbal learning and memory supported by a considerable body of research.
[22] The retest reliability and practice effects are consisted with those for the original CVLT and other list-learning and memory tasks such as the Hopkins Verbal Learning Test-Revised (HVLT -R).
[25] Validity studies[26] show the test is moderately correlated (0.32-0.4) with the WISC-R vocabulary subtest[27] (Delis, Kramer et al. 2004).
The original test had often been criticised as being biased towards individuals of higher education and functioning, as well as reflecting a narrow range of memory performance.
The conclusion that was reached was that it provided valuable qualitative information, but it failed to provide normative data[29] It includes the addition of a forced choice trial to assess level of effort, the inclusion of recall discriminability indices, which takes into account the number of correct words recalled but also take into account words that were not on the original list.
A nine-word short form has also been introduced to improve the utility of the test in assessment of patients with severe cognitive dysfunction.
The great weakness of the CVLT-II is the lack of clinical data for many new indices, particularly the new forced choice discrimination task.