To understand misconceptions with rational numbers (i.e., fractions, decimals, and percentages), we administered an assessment of rational numbers to 331 undergraduate students from a 4-year university. The assessment included 41 items categorized as measuring foundational understanding, calculations, or word problems. We coded each student's…

The interpretation of cognitive test scores often leads to decisions concerning the diagnosis, educational placement, and types of interventions used for children. Therefore, it is important that practitioners administer and score cognitive tests without error. This study assesses the frequency and types of examiner errors that occur during the…

Although structural equation modeling (SEM) is one of the most comprehensive and flexible approaches to data analysis currently available, it is nonetheless prone to researcher misuse and misconceptions. This article offers a brief overview of the unique capabilities of SEM and discusses common sources of user error in drawing conclusions from…

Examined the extent of examiner error during administration of the Wechsler Adult Intelligence Scale (WAIS) by practicing school psychologists and school psychology students eligible for state certification as psychometrists. A number of examiner item scoring and administration errors were observed for numerous subtests. (RC)

Investigated specific problem caused by traditional method of teaching students to administer Wechsler Adult Intelligence Scale-Revised. Analysis of 180 protocols by 26 graduate students revealed average of 8.8 mistakes per protocol. When errors were corrected, 81 percent of Full Scale intelligence quotients were changed. Students' performance…

Analyzed for examiner errors 55 Wide Range Achievement Test-Revised (WRAT-R) protocols completed by 9 practitioners for metropolitan school district. All practitioners made errors, which occurred on 95 percent of protocols and averaged 3.0 errors per protocol. Most frequent errors included failures to obtain correct ceiling or basal, and failures…

This report is a review of reliability data on the PPVT obtained from 32 research studies published between 1965 and 1974. For average children in the elementary grades, and for retarded people of all ages, PPVT scores remained relatively stable over time and there was close equivalence between alternate forms. (Author)

Examined performance and error patterns of 50 bilingual Mexican-American third through fifth graders on the Expressive One-Word Picture Vocabulary Test (EOWPVT) and the Peabody Picture Vocabulary Test-Revised (PPVT-R). The EOWPVT had adequate concurrent validity with PPVT-R. On both tests, scores were almost two standard deviations below normative…

This study compared the WISC-R and PPVT scores for a group of 65 students classified as mentally retarded, ranging in age from 7.5 to 14.5. For this sample of mildly retarded children and youth, the PPVT IQ score is significantly higher than the Full Scale IQ from the WISC-R. (Author)

The type and frequency of a variety of clerical errors were investigated in protocols from the 1949 and 1974 editions of the WISC. Potential consequences of such errors and a discussion of ways to lower the rate are presented. (Author)

Examined computational errors made by educable mentally retarded students on the arithmetic subtest of the Wide Range Achievement Test. Retarded students had a lower percent of grouping and inappropriate inversion errors and a higher percent of incorrect operation errors than regular students had in Engelhardt's study. (Author)

Evaluated the technical aspects of three Wechsler Intelligence Scale for Children-Revised (WISC-R) administrations of five psychology graduate students using the WISC-R Administration Observational Checklist (WAOC) to evaluate interrater agreement. Students performed significantly better on the second than on the first observation, with…