The impetus for this volume began with our research in the 1980's involving serial neuropsychological evaluation with various patient populations. At that time, reports on the practice effects associated with routinely utilized clinical neuropsychological instruments were sparse. While test-retest data were available for almost all assessment instruments, this was usually in the form of correlation coefficients and not changes in mean performance between or across assessment periods (see McCaffrey & Westervelt, 1995 for a detailed discussion of these and related issues). Clinical neuropsychological practitioners had few guidelines to assist them in determining if a change in a patient's performance across assessments was due to an intervention, maturation, practice effects, or a combination of factors. This volume represents our efforts at reviewing the literature between 1970 and 1998 and extracting the reported information on practice effects. The tables include the assessment instrument used, information on the subject/patient groups, the sample size (n}, gender, age, intervention, interval between the assessments, scores at both assessment points, and the citation. Those studies that reported data on more than two assessment points are indicated by a notation~ however, any data beyond the second assessment are not reported and the interested reader should refer to the original article. The tables are arranged alphabetically for the most widely used assessment instruments. Those instruments for which there was limited data on practice effects are grouped by "domain" (e. g.

SUMMARY Meehl and Rosen (1955) Wrst demonstrated the importance of base rates in psychologicalassessmentnearlyWvedecadesago. Theseauthorsstated, ''Thechief reasonforourignoranceofthebaseratesisnothingmoresubtlethanourfailureto computethem''(pg. 213). Researcherscontinuetoreportthatbaseratesarestill largelybeingignored(Duncan&Snow,1987;Gouvier, Hayes,&Smiroldo,1998). It isbecauseofthisgapintheliteraturethatthecurrentbookPractitioner'sGuideto SymptomBaseRatesintheGeneralPopulationandthepreviousbookPractitioner's GuidetoSymptomBaseRatesinClinicalNeuropsychology(McCaVreyetal. 2003) werecreated. Ifthediagnosticaccuracyofourclinicaldecision-makingprocessand ourtestinginstrumentsaretobeestimated, wemustcalculatethebaseratesofthe symptoms, disorders, anddiseasesweassessforonaregularbasis. Itishopedthatthepresentbookwillaidneuropsychologicalpractitionersand otherhealthcareprofessionalsintheevaluationofthepresentingcomplaintsoftheir patients. Baseratesareofutmostimportanceintheestimationofdiagnosticaccuracy ofneuropsychologicalandpsychologicalassessment, aswellasanyotherformof testing, aswellasintheinterviewanddiVerentialdiagnosticprocess. Itishopedthat thesetwovolumeswillencourageadditionalresearcherstoreportbaserateinfor- tion as well as detailed information regarding the population from which this informationwasobtained. Inordertoestimatetheaccuracyofourclinicaldi- noses/decisionsthataremadeonadailybasis, wemustunderstandtheimportanceof baserateinformationandmakeeveryattempttocollectandreportthisdata. Last, thecurrentintroductionismeanttoprovideabriefoverviewofbaseratesandtheir utilityinclinicalneuropsychology. Ifthereaderwishestogainmoredetailedund- standing regarding base rates s/he is referred to Practitioner's Guide to Symptom BaseRatesinClinical Neuropsychology(McCaVrey, Palav, O'Bryant,&Labarge, 2003)aswellasothersources(e. g., Gordon,1977;Gouvier1999,2001;Meehl& Rosen,1955). Key for Using Tables Gender: Males/Females Age: Mean (Standard Deviation); Range Race: Caucasian/African American/Hispanic/Asian Native American/Other Timeframe: timeframe of symptom report SAMPLE TABLE CHARACTERISTICS Schaughency, et al. (1994) n = 943 Diagnostic Criteria: Gender: 483/460 Age: 15 Race: Population Setting: community Nationality: New Zealand Other Sample Characteristics: Method of Reporting: self-report Timeframe: current 5 II / Control Groups: Adult COLLEGE STUDENTS Machulda, et al. (1998) Population Setting: college n = 141 undergraduates Diagnostic Criteria: Nationality: US Gender: 49/92 Other Sample Characteristics: Age: 20. 7 (18-22) Method of Reporting: self-report Race: 268/88/66/7/0/9 Timeframe: Symptom % Symptom % anxiety 87 headache 57 concentration difference 80 irritability 74 depression 71 sensitive to light 26 disordered sleep 41 sensitive to sound 16 dizziness 19 fatigue 83 Freeston, et al. (1996) Population Setting: university n = 583 undergraduates Diagnostic Criteria: Nationality: Canada Gender: 216/367 Other Sample Characteristics: Age: 22. 6 (4. 6) Method of Reporting: self-report Race: 268/88/66/7/0/9 Timeframe: Symptom % Symptom % difficulty concentrating or 16. 5 muscle tension, aches, or 17.

While conducting research on intellectual and neuropsychological perfonnance of various patient populations across time, we became aware of the lack of information concerning practice effects associated with many widely used assessment instruments. Although test-retest data were available for almost all of these instruments, it typically came in the form of correlation coefficients and mean changes in performance between assessments was often absent. In a 1995 article (McCaffrey & Westervelt, 1995), we discussed a number of issues relevant to serial neuropsychological and intellectual assessment and concluded that clinical neuropsychological practitioners had few guidelines to assist them in interpreting change in a patient's performance across assessments. This volume represents our efforts at reviewing the literature between 1970 and 1998 and extracting the reported information on practice effects. The tables include the assessment instrument used, information on the subject/patient groups, the sample size fu}, gender, age, intervention, interval between the assessments, scores at both assessment points, and the citation. The tables reflect the existing published literature within intellectual assessment and, therefore, some instruments (e.g., Wechsler tests) comprise a majority of the tables whereas others (e.g., Raven's Progressive Matrices, Stanford-Binet) do not. The test index is arranged by the name of the test as reported in the specific article. We caution readers to refer to the original articles if additional or more specific information is needed.

The impetus for this volume began with our research in the 1980's involving serial neuropsychological evaluation with various patient populations. At that time, reports on the practice effects associated with routinely utilized clinical neuropsychological instruments were sparse. While test-retest data were available for almost all assessment instruments, this was usually in the form of correlation coefficients and not changes in mean performance between or across assessment periods (see McCaffrey & Westervelt, 1995 for a detailed discussion of these and related issues). Clinical neuropsychological practitioners had few guidelines to assist them in determining if a change in a patient's performance across assessments was due to an intervention, maturation, practice effects, or a combination of factors. This volume represents our efforts at reviewing the literature between 1970 and 1998 and extracting the reported information on practice effects. The tables include the assessment instrument used, information on the subject/patient groups, the sample size (n}, gender, age, intervention, interval between the assessments, scores at both assessment points, and the citation. Those studies that reported data on more than two assessment points are indicated by a notation~ however, any data beyond the second assessment are not reported and the interested reader should refer to the original article. The tables are arranged alphabetically for the most widely used assessment instruments. Those instruments for which there was limited data on practice effects are grouped by "domain" (e. g.

The growth of clinical neuropsychology has been unprecedented. This growth has been oriented more toward the provision of than toward the foundation for services. Thus, while a greater number of psychologists are performing a greater number of neuropsychological procedures, there seems to us an uneven parallel growth between these services and the empirical foundations for them. It should come to no one's surprise that increasingly aggressive attacks on the field have been leveled. Despite these attacks, clinical neuropsychology con tinues to enjoy exceptional growth within psychology and acceptance by other health practitioners, insurance companies, legislators, judges, juries, and above all, consumers of our services. Growth without self-reflection is a dangerous enterprise, as is growth without directions. We find it disconcerting that existing and limited "self analysis" has assumed that neuropsychological dysfunction is immune to the same variables that affect psychological dysfunction. Some attention has been paid to the most obvious ones, such as age, but all others have been ignored and/ or misunderstood. This neglect has spawned a body of knowledge replete with questionable data and unfounded conclusions. Hence, it is surprising that clinical neuropsychologists consider themselves to be more scientifically sound than their regular clinical counterparts.

The Practice of Forensic Neuropsychology focuses the awareness of neuropsychologists on the critical areas of forensic practice that should be considered during each phase of a scientific neuropsychological examination/investigation. Written by three eminent neuropsychologists and a seasoned attorney, this important book contains practical information and guidelines for conducting valid and reliable forensic neuropsychological examinations that aid the 'trier-of-fact' in both civil and criminal settings. The authors also include vital information to help attorneys evaluate neuropsychological claims put forth by their own or opposing experts.

This volume serves as an aid in the process of differential diagnosis which frequently confronts neuropsychologists. The guide is a compendium of information of the base rates of symptoms across a variety of disorders which neuropsychologists encounter. In addition to serving as a convenient source of information on symptom base rates, this volume also contains detailed cross referencing of symptoms across disorders. It is intended for use by clinical neuropsychologists and psychologists.

The Practice of Forensic Neuropsychology focuses the awareness of neuropsychologists on the critical areas of forensic practice that should be considered during each phase of a scientific neuropsychological examination/investigation. Written by three eminent neuropsychologists and a seasoned attorney, this important book contains practical information and guidelines for conducting valid and reliable forensic neuropsychological examinations that aid the 'trier-of-fact' in both civil and criminal settings. The authors also include vital information to help attorneys evaluate neuropsychological claims put forth by their own or opposing experts.

The growth of clinical neuropsychology has been unprecedented. This growth has been oriented more toward the provision of than toward the foundation for services. Thus, while a greater number of psychologists are performing a greater number of neuropsychological procedures, there seems to us an uneven parallel growth between these services and the empirical foundations for them. It should come to no one's surprise that increasingly aggressive attacks on the field have been leveled. Despite these attacks, clinical neuropsychology con tinues to enjoy exceptional growth within psychology and acceptance by other health practitioners, insurance companies, legislators, judges, juries, and above all, consumers of our services. Growth without self-reflection is a dangerous enterprise, as is growth without directions. We find it disconcerting that existing and limited "self analysis" has assumed that neuropsychological dysfunction is immune to the same variables that affect psychological dysfunction. Some attention has been paid to the most obvious ones, such as age, but all others have been ignored and/ or misunderstood. This neglect has spawned a body of knowledge replete with questionable data and unfounded conclusions. Hence, it is surprising that clinical neuropsychologists consider themselves to be more scientifically sound than their regular clinical counterparts."