Critique of the Wechsler Memory Scale Third Edition WMS III

Wechsler Memory Scale-Third Edition (WMS-III)

This is a paper that reports and critiques the Wechsler Memory Scale-Third Edition (WMS-III). It has sources in APA format.

Standardized testing has become a norm for structuring studies on human behaviors. Studies on cognitive abilities, performance, behavior pattern as well as memory testing all have a great deal of dependence on the choice of the kind of tests adopted and the validity of the test is also dependent on the instruments used by the researcher. In the traditional model of assessment, psychologists and other professionals of similar fields depend on surveys and long duration of studies to be able to come to certain objective conclusions.

However, in the modern scientific environment, such assessments can be done through the use and support of instruments that are easily available as "kits" in the market. The basic aim of these instruments is to enable professionals to assess different objectives enabling them to learn more about their subjects whether they be children or adults. The problem with traditional instruments is that they proved to be tedious and takes a lot of time to diagnose the results whereas in the new kinds of instruments, the time frame for the diagnosis is becoming less and less. The administrator of the test therefore is assured of the degree of accuracy and at the same time the authenticity of the results. For this reason, in the recent year's organizations, institutions and professionals aim to devise instruments to meet the need for ready to assess instruments [Handbook of Psychological Assessment, 1990]. One such instrument is the Wechsler Memory Scale-Third Edition (WMS-III).

The WMS-III is a scale for assessing learning and memory functions in adults of age between 16 and 89 years old. The scale is divided into subtests which include testing of:

1)"verbal/auditory memory, 2) visual/nonverbal memory, and 3) attention/working memory" [Weiss, 2003].

The WMS-III's subtests as mentioned above have a combination of rapid and delayed result oriented components so that the factors that contribute to the assessments are structured according to a five-factor model. The factor model is the delayed factor. Larry Weiss in his analysis of WMS-III indicated that the results of the factor analytic work presented in the WMS-III model is still debatable as other researchers indicate the inability of the assessment to replicate the factor structure. Yet there is no doubt that this factor structure has to be further studied in order to come to conclusive results of the WMS-III's assessment criteria and validity.

In most assessment tools the tests rely on specific structured procedures and instructions so that the administrators can read the results in accordance to the problem as the criteria. Experience with the tests as well as understanding of the test procedure is important because as participants would want to ask test administrators of the role of the factors that are associated with the tests and also what is expected of the participants during the process. In psychological tests for example administrators must be motivated to identify the utility of the test exercise in order to help support the participants to pay more attention on the criteria set by the test. Furthermore, instruments are also responsible for the determination of the kind of environment in which the test participants are influenced by. The differential in the environment can influence the kind of decisions they make while taking the test thereby influencing the result of the assessments.

Given these environment for choosing an assessment tool, the WMS-III in this regard has proven to be one of the most powerful memory assessment tool available to professionals of neuropsychological. The instrument is used to assess the relationships between the participant's memory and intellectual functions. The score that result from the data norm is taken into account. The instrument has clinical utility as well as extended floors, redesigned material and scoring software [The Psychological Corporation, 2003]. The instrument uses factor scores and percentile scores for each age group as well as subtest scaled scores for primary or secondary subtests. The duration of the test takes around 30-35 minutes which makes it convenient for professionals who are always crammed for time and at the same time demand quality test results. The qualification of the WMS-III is set a C-Level product. The fact that the instrument does not operate alone but with assisting software as well as complementary norm like the Wechsler Adult Intelligence Scale - Third Edition or the WAIS-III.

According to the Psychological Corporation [2003] the "A primary purpose for developing WMS-III was to expand its clinical utility. To achieve this goal, additional measures of memory were included, and subtest content was revised to more accurately reflect domain-specific memory processes." The factors that are responsible for formulating the five subtests for the WMS is has been useful in creating further subtests known as Faces I and II and Family Pictures I and II that have allowed professionals to pair the subtests with the WMS-R Figural Memory and Visual-Paired Associates subtests. An example of the score can be viewed in the following table:

Table 1: Subtest Scores and Percentiles

Subtests

Abrv

Immediate

Raw

Expt

SS

RGSS

Logical Memory Recall

LM-I

Faces Recognition

Verbal Paired Associates Recall

VPA-I

Family Pictures Recall

FP-I

Immediate Average

AVG IM

Letter-Number Sequencing

L#S

Spatial Span

SSp

Working Memory Average

AVG WM

Delayed

Logical Memory Recall

LM-II

Faces Recognition

Verbal Paired Associates Recall

VPA-II

Family Pictures Recall

FP-II

Delayed Average

AVG DEL

Auditory Recognition

AR-D

Composits

Learning

Lrn

Single Trial

1st Trl

Source: Psychological Corporation

The WMS-III subtests use the summary index scores for organization of its scores. A limited number of scores are only considered for this primary index. The score given are used to determine the interpretative focus. The Primary Index include: "Auditory Immediate, Visual Immediate, Immediate Memory, Auditory Delayed, Visual Delayed, Auditory Recognition Delayed, General Memory, and Working Memory" [Psychological Corporation, 2003].

But this is not all. The Primary index is further evaluated based on the clinical meaning of the memory functions which include:

Single-Trial Learning: Evaluates immediate memory capacity

Learning Slope: Evaluates change over multiple learning trials

Retention: Evaluates percent retention of material from immediate to delayed

Retrieval: Evaluates discrepancy between recognition and recall" [Psychological Corporation, 2003].

Thus, the usefulness of the WMS-III as predicted by professionals is based on the fact that it is an instrument that can be used in complement with other memory assessment tools like the WAIS-III. This helps the professionals to determine and minimize discrepancy when they are dealing with IQ and memory tests thereby allowing them to achieve their focus objectives. This is especially useful in recovering focal memory impairment cases. The extended floor function for example allows for the assessment of participants with cognitive functioning problems and the subtests allows the WMS-III to recognize the formats required immediately for engagement.

One of the features that distinguish the WMS-III from the rest of the instruments is the fact that the focus of the instrument's creation had been an improvement on the older version. The redesigning of this popular scale has given professionals the power to transition from the WMS-R to the WMS-III assessment criteria without having to compromise their test designs. Clinical group studies for example who are currently using other instrument models like the Children's Memory Scale or the SMST and the WAIS-III and WMS-R can concurrently utilize these instruments while transitioning to the WMS-III. The validity of their studies are not compromised because the WMS-III can diagnose older adolescents along with adults; it can also give results pertaining to studies related to reading disabilities, math disabilities, attention deficit disorder, schizophrenia as well as closed head injury, chronic alcoholism, Alzheimer's disease, Parkinson's disease, Huntington's disease and Korsakoff's syndrome etc. These are but some of the neuropsychological aspects and cases that WMS-III can diagnose without compromising the utility of the previous assessment tools and their results.

But perhaps the most attractive feature of this instrument is the fact that the WMS-III allows for summarization of results and concise scoring reportage. This is critical especially when professionals are crammed for time and yet at the same time have to compile results of their extensive results. The kit comes with the video to allow for users to have an in depth knowledge and comprehensive training of the new edition based on the interactive sessions viewed with the country via satellite. The training material is an added feature to the scale because it demonstrates the utility and the effective usage of the instrument thereby allowing acceptance among clinicians.

To test WMS-III in accordance to the standardized tests requirements, researchers like Weiss et all [2001] adopted a sampling investigation. A sample of 1250 is taken with the original factor analyses. The result of the test of the sample is then calibered so that a second sample can be used as an independent observation using 858 sample for cross validation purposes. The result of the test indicate that there are age bands that conformed to the calibration and validation samples The age groups include 1) 16-89 years; 2) 16-29 years; 3) 30-64 years; and 4) 65-89 years. The subtests of the factors were also scored and the measurement is set against the subtests according to the categorization like "Letter-Number Sequencing, Spatial Span, Logical Memory Immediate, Logical Memory Delayed, Visual Paired Associates Immediate, Logical Memory Delayed, Family Pictures Immediate, Family Pictures Delayed, Faces Immediate, and Faces Delayed" [Weiss, 2002]. The resulting assessment can be used for coming to the conclusion that the currently published factor structure of the five factors in the model are constructed identically to the original factors as indicated in the WMS-III Technical Manual. The results of these factors include:

Model 1 a single-factor model

Model 2 a two-factor model -- working memory and auditory memory

Model 3 a three-factor model -- immediate memory, delayed memory, and working memory

Model 4 a three-factor model -- auditory memory, visual memory, and working memory

Model 5 a five-factor model -- auditory immediate memory, auditory delayed memory, visual immediate memory, visual delayed memory, and working memory" [Weiss, 2002].

To assess the nature of the result from the WMS-III sampling, the researcher has conducted a cross validation data analysis of the various factors so as to determine e whether the numerical estimation and output generated from other instruments and those of the WMS-III are the same or not. The other tests include the LISREL and the AMOS which confirmed similar results of the same procedure [Arbuckle & Wothke, 1999; SAS Institute, 1989]. The assessment thus confirm that the calibration of the sample used for testing WMS-III through cross validation of the five factors model do to some extent collaborate with other tests. However, the researchers have observed that the model 3 which is basically a delayed factor do not have a collaborative solution. Instead it is indicative of the fact that the two models that were not fitting to the data can result in wrong estimation between the delayed factors and the sensory modality [Weiss, 2002]. As a result of these findings it can be concluded that the interdependency of the tasks of the delayed memory are basically the same but may offer wrong interpretative results. There are some areas like the model 4 and the three factor model which includes visual memory, auditory memory and working memory can be best estimated with the help of the WMS-III structure.

The results implies that although there is a high level of correlations between the conditions of the delayed factors with the various other instruments but the extent of the measurement of the clinical knowledge through memory tests is still limited as delayed memory and other various memory types are difficult to evaluate. The evaluation requires the use of a combination of delayed memory and factors that contribute to the clinical settings. Other than that the authors recommend that the factor analysis inherent in the WMS-III must be first explored through the neuropsychological patients before they should be subjected to the delayed or immediate memory clinical assessment process. The above experiment for testing the instrument makes it clear that although there is a great deal of areas that the WMS-III can cover but the mixture of the memory profile of individuals are heterogeneity in nature and at times may become obscure to the delayed functions which is a criteria for testing in the WMS-III for specific disorders.

To test, another research is taken into account to compare the expanded WMS-III Standardization Protocol to the those of the WMS-III Among Temporal Lobectomy Patients. Robert C. Doss, Gordan J. Chelune and Richard Naugle [2000] in their study studied the differences between the expanded standardization protocols that is often used for deriving results from professional instruments, in this case the WMS-III. The researchers anticipate the results would offer some view on the Primary Indexes using a neurological sample. The comparability sample in this case has been taken of 63 patients with temporal lobotomy and were administered the standardization protocol while some were administered to the derive norms of the final published version. The comparability is based on age, sex, education, seizure duration, post surgical seizure status and the full scale IQ. The result of the research although do not offer any comprehensive understanding of the two versions of the WMS-III but nevertheless it does allow the researchers to understand the fact that there is hardly any difference between the group sample and that for temporal lobotomy patients the scores of the two versions of the WMS-III are the same.

In another test by D' Urso [2001] the researcher attempts to establish a relationship between the perceptual modality performances and the short-term memory developmental capacity of Math and English students using the WMS-III. The basic premise of the author had been to investigate the validity of WMS-III and another instrument called the Multi-Modal Paired Associates Learning Test III (MMPALT III). The aim had been to expand the knowledge base of the learning styles of the students and measure the perceptual modality that is usually found in performance-based testing processes. A sample of 48 English and 37 math students were taken from a local college and subjected to subtests. The results were evaluated whereby the Print, Aural, Interactive and Visual subtest scores were taken into account for the Multi-Modal Paired Associates Learning Test III and the Aural and Visual for the WMS-III scores.