The term formal applies to any completely objective method for making psychometric or logical interpretive decisions. These methods have the scientific characteristics of objectivity, repeatability, validity, and predictability. Formal methods provide information that is quantitative or logical. In neuropsychology, they provide an objective, quantitatively accurate description of a relationship between aspects of brain functioning. This chapter is devoted to a relatively brief examination of the formal methods used in neuropsychology. Formal methods are mathematical or logical. They are quantitative or taxonomic. They are derived directly from scientific, psychometric methods that do not require clinical judgment. These include computerized testing, which appears to be a major aspect of the next phase of neuropsychological assessment. Their essence is objective validation. The advantage of formal methods is that they can be validated and their accuracy determined (rate of error). Therefore, they are reliable for medical and forensic purposes. Their ultimate form is computerized assessment that combines administration, scoring, and interpretation. Ultimately, neuropsychology will develop in this direction.

This chapter provides an introductory, but brief, history of the development of scientific assessment batteries in neuropsychology. About 30 years ago, neuropsychology was on the edge of discovering a new formal assessment methodology. This was a computerized assessment scoring and basic interpretation program. This could have been integrated with computer technology. Since the 1980s, with the exception of some relatively unrecognized work by a few neuropsychologists, the field has been dominated by the clinical or flexible method that uses flexible batteries and clinical judgment as the basis for assessment. In the last few years, a new neuropsychological assessment method made its appearance. This is the computerized neuropsychological testing program. The program that appears to be the most challenging to traditional clinical neuropsychology assessment is the MindStreams program. This program is designed for medical practice and requires no neuropsychologist. The results of the program include measures of the amount of impairment for various major cognitive domains. These results are delivered to the physician in a printout “immediately” after the patient is tested. The printout is designed so that a doctor, such as a neurologist, can quickly issue a report on the cognitive status of the individual.

Formal neuropsychology is based on science and hence the chapter reviews the nature of science. The essence of science is to demonstrate the existence of knowledge by means of objective observation methods that are repeatable, testable, and verify predictions. There are two forms of science: discovery and justification. Discovery introduces constructs or theories and methods to science, which are often incorrect. Consequently, to be reliable, science must justify its procedures by a validation process that usually determines their accuracy. All discovered methods and information must be justified to be reliable. Thus, justification is the essence of science. To accomplish this process, science requires instrumentation. This chapter lays particular emphasis on instrumentation, because the basis of neuropsychology is its instrumentation. This instrumentation was derived from psychology, although the form of the instrumentation in neuropsychology pertains to testing procedures related to brain functioning. Instruments sample an area of nature, isolate it, transform it into a quantitative form, and record it as objective information. This entire process is not dependent on human judgment. Instrumentation is also the basis for validation procedures. They are objective testing processes that determine the accuracy and thus the reliability of the relevant knowledge.

The basis of all neuropsychological assessment procedures, including forensics, is justification. Justification is derived from general reliability. Neuropsychological assessment knowledge is reliable if, and only if, it is derived from methods that have been validated using psychometric procedures that are generally acceptable in science. This chapter elaborates the nature of justification. It emphasizes the distinction between research in basic theoretical neuropsychology and assessment research. It deals with the concepts used to justify unstandardized batteries, including the difference between medicine and neuropsychology. Further the chapter deals with the requirements for a standardized battery, including norming and validation. A battery may be validated by either clinical judgment or psychometric procedures. Because whole batteries are used for interpretations and provide information different from that derived from individual tests, psychometric procedures must be applied to batteries. Standardized battery norms represent a sample of the general population. Adequate representation depends on the size of the sample, the location of subjects, and whether they are neurologically normal.

This chapter is a critique of the newest criticisms of the Reitan method by Lezak and her associates (Lezak et al., 2004, pp. 670–677). In their critique, she and her associates confuse Reitan's scientific method, which is perhaps the most rigorous methodology that has been used in neuropsychology, with his method of assessment. Thus, these papers constitute a dialogue between these two approaches to neuropsychological assessment. This chapter demonstrates that the multitude of studies establishes the validity and rate of error of the Halstead–Reitan Battery (HRB) and Halstead–Russell Neuropsychological Evaluation System (HRNES–R). In contrast, there are no published studies examining the validity of Lezak's method, which uses a whole battery, and there is no information concerning experimental control procedures or rate of error for that methodology. As such, Lezak's method, as with all clinical judgments based on flexible methods, cannot be defended as forensically reliable. Consequently, the fallacy of nonrefutation applies to Lezak et al.'s review of the HRB and HRNES–R. In the same book in which Lezak et al. implied that the HRB and HRNES, which would include the HRNES–R, should not be used because they had so many problems, Lezak's method is presented as the ideal procedure. However, nowhere in this vast book are any studies cited that provide any indication of the validity or accuracy of the Lezak method. As such, the entire description of Lezak's methodology should be considered as an unvalidated position paper rather than as a validated methodology. By contrast, the HRB and HRNES–R are validated methodologies.

This chapter deals with the theoretical relationship between brain functioning and neuropsychological testing. This relationship has recently received a great augmentation by the introduction of scanning techniques in neurology. Until the development of scanning methods, the functioning of the brain was considered to exist in a black box so that it could not be perceived. Psychology developed tests unrelated to brain functioning, and neuroscience examined brain functioning with little emphasis on tests. However, although scanning determines the location of a function, it does not determine the nature of that function. This nature of a function is determined by the form of neuropsychological tests. The test is a task that the brain is required to perform and that demonstrates the function of a particular area of the brain. Thus, the relationship between neuropsychological tests and brain functioning can be determined with greater precision than previously.

This chapter deals with the methods used in neuropsychology to examine brain functioning. These methods are research and applied assessment procedures. Assessment procedures are based on double disassociation (Teuber and Reitan). Generally, they are combined into multiple disassociations. These compose a standardized integrated battery. Standardized batteries consist of either fixed raw scores or scale scores. Standardization requires a common metric, conorming, demographic adjustments, and comprehensive content. Scale scores may have universal coverage from about age five to an adult IQ of 140. Absolute scales are fixed and are not direct samples of a particular population. The content of tests requires comprehensiveness, balance, redundancy, and efficiency. This chapter emphasizes the use of test batteries, because psychometrics has examined individual tests to a far greater extent than this work can deal with. It will examine the way a neuropsychological assessment battery should be constructed in order to model the functioning of the brain. This presents the basic psychometric theory for constructing an assessment battery.

This chapter is a republication of the first paper defending the HRB against criticism by Lezak. This critique demonstrated that Lezak confused clinical judgment used with a fixed battery, the HRB, with clinical judgment utilized in her method. Lezak's book is excellent in discussing the hypothesis-testing method and reviewing the research on single tests from that perspective. However, Reitan's method is basically not a hypothesis-testing method but a pattern-analysis method. This pattern-analysis method is generally misunderstood by Lezak and many other neuropsychologists. Because many of Lezak's criticisms are derived from this misunderstanding, a discussion of her review must involve an explanation of the method used by Reitan. The chapter discusses issues that include types of batteries, legitimate review methods, and Reitan's method. It demonstrates that almost all of Lezak's criticisms of the HRB and the HRNES are incomplete, misleading, or erroneous. Her critique of the Reitan method involved a confusion of terms. In spite of attempts to discredit the HRB, not a single sound study questioning the validity of the HRB was presented, whereas many studies have demonstrated its validity. The fallacy of nonrefutation asserts that it is a fallacy to condemn methods that have been validated while recommending procedures that have not been validated. Lezak questions Reitan's method, the HRB, and the HRNES, which have been thoroughly validated, while presenting no validating studies of her own recommended methods.

This chapter examines the research on volunteer norms used for studies with the HRB and finds that they are all almost one standard deviation above normal. This means they are inappropriate as control groups for neuropsychology. The adequacy of neuropsychological norms depends on the characteristics of the subjects whose data are used. Volunteer participants and neurologically normal participants in major normative studies show markedly different patterns of test performance that reflect on the inadequacy of using volunteer participants to develop norms. In this study, when all of the Halstead–Reitan Battery norming studies with an N of 200 or more were examined, Wechsler FSIQ score differences of approximately one standard deviation above average for the volunteer normative participants was found. The norms from the norming study using neurologically normal patients were essentially average. The exclusion of neurologically suspect participants from volunteer normative studies lead to a bias reflected in artificially inflated levels of performance and a restricted range of variation. This sets inappropriately rigid assessment cutoffs for defective performance. Furthermore, data collection from neurologically normal subjects follows the same format as that used in the assessment of neurologically compromised subjects, whereas the more research-oriented protocol used to collect normative data from volunteer participants does not.

Accuracy is equivalent to the rate of error and is a primary component of predictive validation. The criteria for validity and accuracy have not been adequately examined in neuropsychology. The accuracy of a test procedure cannot be better than its criterion, which may not be above 80% in neurology. This chapter presents a a crucial discussion of the accuracy of various formal methods that have been used in neuropsychology. It attempts to be as thorough as possible in its selection of procedures to examine. Nevertheless, this examination is restricted to procedures that have developed from the Halstead–Reitan Battery (HRB). Various types of psychometric procedures that are used to determine the accuracy of brain-damage studies include the Halstead Index (HI), the average impairment rating (AIR), the Neuropsychological Deficit Scale (NDS), and the average impairment scale (AIS). Accuracy is another way of stating the rate of error for a procedure. The major examined procedures are indexes, decision-tree algorithms, discriminate analysis, and clinical judgment. The chapter also deals with the criticism that neuropsychologists have applied to these formal methods. Finally, it briefly discusses some of the newer methods of creating formal procedures