Industrial Reading Test Technical Manual Copyright © 2006 NCS Pearson, Inc. All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. ii Introduction 1 Description of the Test Uses of the Test Development of the Test 1 1 1 Directions for Administration and Scoring Testing Conditions Preparing for the Administration Administering the Test Scoring and Reporting Test Security Accommodating Examinees with Disabilities 3 3 3 3 4 4 4 Norms 5 Evidence of Reliability 13 Evidence of Validity 14 Correlations with Other Tests 15 References 27 iii List of Tables IRT Scores and Corresponding Percentile Ranks 6 IRT Means and Standard Deviations for Vocational High School Students by Programs 9 IRT Means and Standard Deviations for Various Samples of Adults in Schools and Industry 12 IRT Alternate-Form Reliability Coefficients and Standard Errors of Measurement 13 IRT Split-Half Reliability Coefficients and Standard Errors of Measurement 14 Correlation Coefficients Between the IRT and Grades of High School Students in Vocational Training Programs 16 Correlation Coefficients Between the IRT and Final Grades of High School Students in Specific Vocational Training Programs 18 Correlation Coefficients Between the IRT and Criteria for Students in Special Remedial and Vocational Programs 22 Correlation Coefficients Between the IRT and Criteria for Industrial Groups 23 Correlation Coefficients Between the IRT and Other Tests 24 iv Introduction Description of the Test The Industrial Reading Test (IRT) is a measure of reading ability developed for the use in industry and vocational schools. The passages on the test deal with such topics as basic principles of first aid, kinds of clothing and protective devices used by technical workers, the importance of blueprints in manufacturing, the metric system, and the like. Two alternate forms of the test are available. The sale of Form A is restricted to business and industry while Form B is available in paper-and-pencil format and can be purchased by both schools and businesses. Each form has 9 passages and 38 items. Some of the passages and items on the IRT are relatively easy while others are more difficult. The test is designed to be within the reading ability of the typical high school vocational student or an older person with a high school education or its equivalent. The test is not recommended for use below the 9th grade. The IRT is intended to be a power test of reading comprehension rather than a measure of reading speed. Most examinees will find the time limit of 40 minutes adequate for completing the test. The IRT yields one score—the total number of items answered correctly. The paper-and-pencil version can be scored either by hand or by machine, and the online version of Form A is automatically scored. Uses of the Test The IRT measures an individual’s ability to comprehend written technical materials. The test can be used to determine the ability of applicants for jobs in industrial settings, or trainees in technical or vocational training programs, to read instructional and jobrelated materials. The IRT is designed so that applicants or trainees will find the material relevant and meaningful. Good performance on the test is not dependent upon previous knowledge of the subject matter. The test simply shows whether or not an individual has the necessary reading ability to perform adequately on the job or to make satisfactory progress in technical training. Companies that provide remedial reading instruction can use the IRT to identify employees or trainees who would benefit from such instruction. Development of the Test The idea of developing an Industrial Reading Test grew out of discussions between staff members of Pearson TalentLens and managerial personnel in various industries that train and employ people for skilled technical jobs. Many of the applicants selected by these organizations find the training programs difficult. The problem appears to be not so much one of poor mechanical skills or lack of Copyright © 2006 NCS Pearson, Inc. All rights reserved. 1 motor coordination, but rather one of inadequate reading ability. Some training programs are rigorous, particularly three- and four-year apprentice programs in construction, mechanical maintenance, electrical installation and repair, and the like. Individuals selected for these programs must be able to read and master difficult technical material in areas such as the design and interpretation of blueprints, basic and applied physics, and industrial electronics. The numerous rules and regulations set forth in company safety manuals must also be read and understood. A readability analysis of representative textbooks and training manuals used in these programs indicated that they were written at a 9th or 10th grade level. An appropriate, professionally developed reading test can provide useful information about the reading level of applicants for such programs. Development of the Industrial Reading Test began with careful consideration of the characteristics of a suitable instrument. First, it was decided that the IRT should be relatively short, and easy to administer and score. A second consideration related to the difficulty level of the passages and items; the reading level of the IRT should be consistent with that of written material the examinees will need to read and comprehend in the course of their training programs. A third consideration was that the content of the test should appear relevant and reasonable. The passages should look like, and read like, excerpts from a training manual or company memorandum. The Occupational Outlook Handbook (U.S. Dept. of Labor, 1978) and Dictionary of Occupational Titles (U.S. Dept. of Labor, 1977), job descriptions, education and training requirements, and other relevant materials were used to determine the content areas, specific subject matter, and the appropriate level of reading difficulty for each topic in the test. Textbooks and manuals used in training programs for technical jobs were also used in determining content and reading difficulty. Each passage written for the IRT, as well as a representative sample of the reference material on which it was based, was evaluated for reading difficulty. Readability estimates were obtained by means of the Dale-Chall formula for estimating readability (Dale & Chall, 1948; Powers, Sumner, & Kearl, 1958). The analyses indicated that all but one of the passages had Dale-Chall readability indexes at the 7th–8th grade level or the 9th–10th grade level. One passage (Form B, page 11) had a Dale-Chall readability index at the 11th–12th grade level. A pool of items was then written for each passage, and the passages and items were tried out on samples of employees and students. Although the IRT was originally designed for industrial use, the preliminary item statistics obtained from a sample of vocational high school students suggested that the test was also appropriate, in content and difficulty level, for vocational students. Consequently, normative and validity data were collected for vocational students as well as for employees in industry. Copyright © 2006 NCS Pearson, Inc. All rights reserved. 2 Directions for Administration and Scoring The computer-based Industrial Reading Test is administered through the TalentLens platform, an Internet-based testing system designed by Pearson TalentLens for the administration, scoring, and reporting of professional assessments. Instructions for administrators on how to order and access the test online are provided at TalentLens.com. Instructions for accessing the IRT interpretive reports are provided on the website. After a candidate has taken the IRT on the TalentLens platform, the test administrator can review the candidate’s results in an interpretive report. Testing Conditions It is important to ensure that the test is administered in a quiet, well-lit room. The following conditions are necessary for accurate scores and for maintaining the cooperation of the examinee: good lighting, comfortable seating, adequate desk or table space, comfortable positioning of the computer screen, keyboard, and mouse, and freedom from noise and other distractions. Preparing for Administration Being thoroughly prepared before the examinee’s arrival will result in a more efficient online administration session. It is recommended for test administrators to take the computer-based IRT prior to administering the test, being sure to comply with the directions and the time requirement. Examinees will not need pencils or scratch paper for this computer-based test. In addition, examinees should not have access to any reference materials (e.g., dictionaries or calculators). Administering the Test After the initial instruction screen for the IRT has been accessed and the examinee is seated at the computer, say, The on-screen directions will take you through the entire process that begins with some demographic questions. After you have completed these questions, the test will begin. You will have 40 minutes to work on this test. The test ends with a few additional demographic questions. Do you have any questions before starting the test? Answer any questions and say, Please begin the test. After the examinee clicks Start Your Test, the sample passage and sample items appear, followed by the actual test passages and items. During the test, examinees may skip items and return to them later. The examinee also may review test items at the end of the test. Examinees have 40 minutes to complete the test. Copyright © 2006 NCS Pearson, Inc. All rights reserved. 3 If an examinee’s computer develops technical problems during testing, the test administrator should move the examinee to another suitable computer location. If the technical problems cannot be solved by moving to another computer location, the administrator should contact Pearson TalentLens Technical Support for assistance. The contact information, including phone and fax numbers, can be found at the TalentLens.com website. Scoring and Reporting Scoring is automatic, and the report is available a few seconds after the test is completed. Adobe® Acrobat Reader® is necessary to open the report. The test administrator may view, print, or save his or her candidate’s report. Test Security Industrial Reading Test scores are confidential and should be stored in a secure location accessible only to authorized individuals. It is unethical and poor test practice to allow individuals, who do not have a legitimate need for the information, access to testscores. Storing test scores in a locked cabinet or password protected file that can only be accessed by designated test administrators will help ensure their security. The security of testing materials (e.g., access to online tests) and protection of copyright must also be maintained by authorized individuals. Avoid disclosure of test access information such as usernames or passwords and only administer the test in proctored environments. All the computer stations used in administering the IRT must be in locations that can be easily supervised with the same level of security as the paper-andpencil administration. Accommodating Examinees with Disability The test administrator should provide reasonable accommodations to enable candidates with special needs to take the test comfortably. Reasonable accommodations may include, but are not limited to, modifications to the test environment (e.g., desk height) and medium (e.g., having a reader read questions to the examinee, or increasing the font size of questions) (Society for Industrial and Organizational Psychology, 2003). In situations where an examinee’s disability is not likely to impair his or her job performance, but may hinder the examinee’s performance on the IRT, the organization may want to consider waiving the test or de-emphasizing the score in lieu of other application criteria. Interpretive data as to whether scores on the IRT are comparable for examinees who are provided reasonable accommodations are not available at this time due to the small number of examinees who have requested such accommodations. If, due to some particular impairment, a candidate cannot take the computeradministered test but can take the test on paper, the administrator could provide reasonable accommodation for the candidate to take the test on paper, and then have the candidate’s responses entered into the computer system. The Americans with Disabilities Act (ADA) of 1990 requires an employer to make reasonable Copyright © 2006 NCS Pearson, Inc. All rights reserved. 4 accommodations for a qualified applicant with a known disability, which would not cause an “undue hardship” to the operation of the employer’s business. Norms The value of a test is based on the extent to which the normative data it is based upon is accurate and relevant to the user’s own population. Locally developed norms are the most useful because they pertain specifically to the group that is of immediate concern. Where such information is not available, the user can be guided by the norms published in the test manual for similar groups. The norms tables are arranged according to the nature of the population tested: vocational high school students; adults in remedial, technical, or vocational training programs; and industrial applicants, apprentices, and employees. Data for the high school samples are grouped according to vocational programs. for students enrolled in comparable programs, average scores did not improve from grade 10 to grade 12. Similarly, the average scores of males and females enrolled in comparable programs or applying for similar kinds of work were not significantly different. Table 1 presents Industrial Reading Test percentile ranks for groups of at least 100 cases. The percentile norms have been devised to encourage realistic interpretation of test scores. The norms in Table 1 include three samples from vocational high schools grades 10– 12, three adult student samples, and four industrial samples. The high school students are enrolled in various programs within three broad occupation categories: service occupations, machine trades, and structural work. The samples within these three groups are quite diverse. Each percentile in the table represents a band or zone of ability for which the indicated percentile is approximately the midpoint. In most cases, each band is five percentile units; however, the zones differ somewhat at the extremes. Thus, a percentile of 5 includes 4 through 7; 3 includes 2 and 3; 1 stands for the first percentile only. Similarly, the 95th percentile includes 93 through 96; 97 includes 97 and 98; 99 stands for only the 99th percentile. Copyright © 2006 NCS Pearson, Inc. All rights reserved. 5 Table 1 IRT Raw Scores and Corresponding Percentile Ranks Vocational High School Students In Programs for Service a a In Programs for Machine Trades b Adult Students In Programs for Structural Work Percentile Occupations Occupations Occupations 99 36–38 37–38 97 95 34–35 33 90 85 80 c In Remedial Mathematics at a Vocational Institute in New d At a Skills Center e At a Vocational Institute in f Mexico in Tennessee Florida Percentile 37–38 37–38 36–38 37–38 99 35–36 34 35–36 34 35–36 33–34 34–35 32–33 36 35 97 95 32 31 30 33 32 31 32–33 31 — 32 31 30 31 29–30 28 — 34 — 90 85 80 75 70 65 60 29 28 27 26 — 30 29 — 30 29 28 27 29 28 27 26 27 26 25 — 33 32 — 31 75 70 65 60 55 25 28 26 25 24 30 55 50 24 27 25 24 23 29 50 45 23 26 24 23 22 — 45 40 35 30 22 21 20 25 24 23 23 22 21 22 21 20 21 20 19 28 — 27 40 35 30 25 19 22 19–20 19 17–18 25–26 25 20 15 18 16–17 21 19–20 17–18 15–16 17–18 15–16 15–16 13–14 22–24 20–21 20 15 10 5 3 13–15 11–12 9–10 15–18 13–14 11–12 13–14 11–12 9–10 13–14 10–12 6–9 12 10–11 8–9 18–19 14–17 12–13 10 5 3 1 0–8 0–10 0–8 0–5 0–7 0–11 N Mean SD 362 23.9 6.9 437 26.2 6.2 467 24.5 7.0 193 24.1 7.2 188 22.4 7.0 140 28.4 6.3 1 N Mean SD Includes students in grades 10–12 in food service and cosmetology programs at 4 schools (3 in PA, 1 in NY). b Includes students in grades 10–12 in machine shop; auto mechanics; diesel mechanics; engine rebuilding; and heating, ventilation, and air conditioning programs at 12 schools (7 in PA, 2 in NY, 1 in MA, 1 in TN, 1 in W VA). c Includes students in grades 10–12 in auto body, welding, electricity or electronics, and carpentry programs at 12 schools (4 in NY, 4 in PA, 1 in FL, 1 in MA, 1 in TN, 1 in W VA). d e f Includes 114 males and 79 females; 60% from minority (Black/African-American and Hispanic/Latino[a]) groups. Includes 99 males and 89 females; 100% from minority (Black/African-American and Hispanic/Latino[a]) groups. Mostly male; mostly White (non-Hispanic). Copyright © 2006 by NCS Pearson, Inc. All rights reserved. 6 Table 1 IRT Raw Scores and Corresponding Percentile Ranks (continued) Applicants for Apprentice Training at a Steel Plant in g h I j Percentile Illinois 99 97 95 90 85 80 g Millwright and Motor Inspector Apprentices at a Steel h Utility Operator and Technician Trainees i Service Technician Trainees at a Technical Training j Plant in Illinois at a Southern Utility Center in Virginia 38 37 36 35 34 — 37–38 — 36 — — 35 37–38 — — 36 — — 38 — 37 — — 36 99 97 95 90 85 80 75 70 65 60 55 33 32 31 30 29 34 — 33 — — — 35 — — — — — 35 — — 75 70 65 60 55 50 28 32 34 34 50 45 40 35 30 25 — 27 26 24–25 22–23 — — 31 30 29 — 33 — — 32 — 33 — — 32 45 40 35 30 25 20 15 10 5 3 1 N Mean SD 20–21 17–19 14–16 12–13 10–11 0–9 145 27.3 7.4 28 26–27 24–25 21–23 14–20 0–13 115 31.3 5.1 — 31 30 28–29 27 0–26 100 33.9 2.5 — 31 29–30 25–28 20–24 0–19 380 33.6 3.9 20 15 10 5 3 1 N Mean SD Mostly male; mostly minority. Mostly male; includes 66 White (non-Hispanic) and 49 minority (Black/African-American and Hispanic/Latino[a]). Mostly male; includes 85 White (non-Hispanic) and 15 minority (Black/African-American and Hispanic/Latino[a]). Mostly male; mostly White (non-Hispanic). Copyright © 2006 NCS Pearson, Inc. All rights reserved. 7 Percentile Table 2 presents means and standard deviations for additional groups of varying size. Some of the student groups are subgroups of the large samples that were the basis for the percentile norms in Table 1. In Table 2, the data are reorganized to show comparative performance on the IRT by specific vocational program rather than by the broad occupational categories used in Table 1. The means and standard deviations in Table 2 are shown, when appropriate, for combined groups of students in similar programs at different schools. In order for these subsamples to be combined, the groups had to be closely comparable in terms of program, grade level(s), IRT scores (mean scores no more than 3 points apart), and sex and racial composition. Table 3 presents means and standard deviations for various adult student and industrial samples of less than 100 cases. The data for adult students and trainees are organized according to type of program. The data for industrial groups are listed separately for each organization and job category. Copyright © 2006 NCS Pearson, Inc. All rights reserved. 8 Table 2 IRT Means and Standard Deviations for Vocational High School Students by Programs Grade Level Sex Race/Ethnicitya N Mean SD 10–12 Mostly Male Mostly white 40 31.8 4.6 Civil construction and drafting programs in Pennsylvania 11–12 Mostly male Mostly white 66 30.1 4.5 Medicine and health programs in New York and Pennsylvania 11–12 Mostly female Mostly white 59 30.7 3.8 Medical lab program in Pennsylvania 10–12 Mostly female Not reported 27 30.5 3.8 Medical and dental programs in Pennsylvania 10–11 Female Not reported 31 21.0 6.0 Graphic arts program in Pennsylvania 11–12 Male White 24 25.2 6.1 Commercial art program in New York 10–12 8 male, 25 female Not reported 33 24.4 7.2 Commercial art program in Pennsylvania 11–12 15 male, 10 female Not reported 25 22.0 8.5 10–12 15 male, 16 female Not reported 31 30.3 4.7 10 Mostly female 13 white, 64 minority 77 17.7 6.0 Data processing program in Pennsylvania 11–12 21 male, 50 female Mostly white 71 28.8 4.9 Data processing program in Pennsylvania 10–12 21 male, 51 female Not reported 72 25.3 5.5 Accounting and data processing programs in Pennsylvania 11–12 Mostly female Mostly minority 30 20.7 6.9 Marketing programs in Pennsylvania 11–12 10 male, 65 female Mostly white 75 25.2 5.5 Programs for Service Occupations Food service programs in Pennsylvania and West Virginia 10–12 7 male, 18 female 14 white 11 minority 25 22.1 7.7 10–12 64 male, 60 female Not reported 124 20.8 7.1 Cosmetology program in Pennsylvania 12 Female White 32 30.4 3.0 Cosmetology programs in Pennsylvania 11 Female Mostly white 111 28.1 4.9 Program Programs in Professional, Technical, and Managerial Work Electronic technology programs in New York and West Virginia Clerical and Sales Programs Typing and shorthand classes in Florida Business education program in Pennsylvania Food preparation and service programs in New York and Pennsylvania Copyright © 2006 NCS Pearson, Inc. All rights reserved. 9 Table 2 IRT Means and Standard Deviations for Vocational High School Students by Programs (continued) Grade Program Sex Race/Ethnicitya Mean N SD Level Programs for Service Occupations (continued) Cosmetology programs in New York and Pennsylvania 10–12 Female Not reported 127 23.3 6.6 10–11 Female Mostly minority 25 16.3 5.8 10–12 32 male, 6 female Not reported 38 23.8 7.5 10–11 Male Not reported 54 22.7 5.5 Machine shop and mill and cabinet programs in West Virginia 11–12 Male White 34 22.3 6.9 Machine shop and metal fabrication programs in Massachusetts 10 Male Not reported 40 25.2 5.9 10–12 Male Mostly white 24 25.0 7.4 Aircraft mechanics program in Pennsylvania 12 Mostly male Mostly white 40 30.7 4.4 Diesel and engine repair programs in Pennsylvania and Tennessee 12 Male Mostly white 27 27.3 5.4 Auto mechanics programs in New York, Pennsylvania, Tennessee, and West Virginia 10–12 Male Mostly white 205 26.6 6.1 Heating and ventilation programs in Pennsylvania 10–12 Male Mostly white 35 25.6 5.4 Air conditioning and auto mechanics programs in New York 11–12 Male Not reported 121 25.3 7.1 Agricultural mechanics programs in New York 11–12 Male White 31 24.5 7.4 Auto mechanics programs in Massachusetts 10–12 Male Not reported 46 24.1 6.5 10 Male Not reported 119 23.6 6.7 10–12 Male Not reported 29 28.1 4.6 Cosmetology program in Pennsylvania Agricultural, Fishing, and Forestry Programs Conservation program in New York Machine Trades Programs Machine shop programs in Pennsylvania General metals trades program in Tennessee Various mechanical repairing programs in Massachusetts and Pennsylvania Bench Work Programs Electrical shop program in Massachusetts Copyright © 2006 NCS Pearson, Inc. All rights reserved. 10 Table 2 IRT Means and Standard Deviations for Vocational High School Students by Programs (continued) Race/Ethnicitya N Mean SD 10–12 Mostly male 39 white, 11 minority 50 22.5 7.0 10 Male Not reported 28 26.1 4.2 Auto body programs in New York, Pennsylvania, and West Virginia 10–12 Male Mostly white 107 21.4 7.1 Welding programs in New York, Pennsylvania, and West Virginia 10–12 Male Mostly white 121 24.1 7.4 Electromechanics and electronics programs in Massachusetts and Pennsylvania 10–12 Male Mostly white 89 29.6 5.2 Electricity and electronics classes in New York, Pennsylvania, Tennessee, and West Virginia 10–12 Male Mostly white 114 28.1 5.9 Basic electricity and electronics courses in New York and Pennsylvania 10–11 Male Not reported 91 27.9 5.6 11 Male Mostly white 29 27.3 5.1 Trade electricity program in New York 10–12 Male Not reported 25 25.9 6.1 Carpentry programs in New York and Pennsylvania 10–12 Male White 70 27.7 5.7 Masonry programs in Florida, Massachusetts, Pennsylvania, and West Virginia 11–12 Male Not reported 74 25.1 6.3 Carpentry programs in Florida, Massachusetts, New York, and Pennsylvania 11–12 Male Mostly white 125 24.0 6.0 Carpentry and masonry programs in New York and Pennsylvania 10 Male Not reported 69 21.8 7.4 Plumbing programs in Massachusetts and Pennsylvania 10–11 Male Not reported 55 21.2 6.8 Carpentry and building maintenance programs in Pennsylvania and West Virginia 10–11 Male 17 white, 9 minority 26 17.7 8.0 Bench Work Programs (continued) Radio/TV and small appliance repair programs in Pennsylvania, Tennessee, and West Virginia Programs in Structural Work Auto body programs in Massachusetts and Pennsylvania Industrial electricity programs in Pennsylvania and West Virginia a Grade Level Sex Program Minority includes Black/African-American and Hispanic/Latino(a) Copyright © 2006 NCS Pearson, Inc. All rights reserved. 11 Table 3 IRT Means and Standard Deviations for Various Samples of Adults in Schools and Industry Sex Race/Ethnicitya N Mean SD 7 male 30 female 30 white, 7 minority 37 27.2 5.8 Adults in clerical programs at a skills center in Tennessee Mostly female Minority 35 23.8 5.7 Adults in mechanical repairing programs at skills centers in New York and Tennessee Mostly male 13 white 24 24.3 6.9 Adults in an auto shop program at a vocational center in California Mostly male White 23 21.1 8.6 Male Minority 29 17.8 8.3 Adults in audio, video, and small appliance repair programs at a skills center in Tennessee Mostly Male Minority 29 24.1 6.6 Adults in auto body and welding programs at a skills center in Tennessee Mostly male Minority 25 22.9 6.6 Adults in electricity and electronics programs at skills centers in Florida and New York Mostly male Mostly white 36 32.6 3.5 29 male Mostly white 64 26.4 7.0 70 male 70 white, 83 29.5 5.4 27 28.7 7.6 Sample Adults in a clerical program at a vocational institute in Florida Adults in CETA (Comprehensive Employment Training Act) programs at a skills center in New York Technical workers at an oil refinery in the South 11 minority 35 female 13 female 13 minority Mill repairmen and motor inspectors at a steel plant in Illinois Male 21 white, Apprentices at a manufacturing company in the South Male Not reported 30 28.4 5.5 Apprentice applicants at a steel plant in Indiana Male 42 white, 72 28.0 6.3 56 28.0 5.7 68 23.1 8.1 6 minority 30 minority Machine operators at a cereal company in the Midwest Male 54 white, 2 minority Technical trainees at a utility in the Northeast a Mostly male Minority includes Black/African-American and Hispanic/Latino(a) Copyright © 2006 NCS Pearson, Inc. All rights reserved. 12 Mostly minority Evidence of Reliability Reliability or consistency of measurement is an important characteristic of any test. The reliability of a test refers to the accuracy, consistency, and stability of test scores across situations (Anastasi & Urbina, 1997). A reliable test has a relatively small measurement error, which is the difference between the hypothetical true score and an individual’s obtained test score. Evidence of reliability is often demonstrated as a correlation coefficient or the standard error of measurement (SEM). Evidence of reliability is demonstrated statistically in several ways. Alternate-form reliability provides an estimate of the degree of relationship between test scores obtained on alternate forms of the test that have been administered on different occasions to the same individuals. Split-half reliability provides an estimate of the test’s internal consistency. Reliability coefficients can vary between .00 and 1.00. The closer the coefficient is to 1, the greater the test’s reliability. The standard error of measurement (SEM) provides a different type of information. This statistic has the advantage of being relatively independent of the spread or variability of groups. It reflects the extent to which a given individual’s test scores would be expected to vary if he or she were administered the test many times (discounting the effects of fatigue and practice). The SEM represents the difference between an individual’s obtained test score and the hypothetical true score. For example, a standard error of measurement of 3 points indicates that, in about two out of three cases, an individual’s obtained score may be expected to lie within 3 points ( + or –) of the “true” score. Table 4 presents alternate-form reliability coefficients and standard errors of measurement for the Industrial Reading Test, derived from the counter-balanced administration of Forms A and B to a sample of 61 adult students at a vocational skills center in Tennessee. The time interval between testings was three months. Table 4 IRT Alternate-Form Reliability Coefficients and Standard Errors of Measurement Sample N r12 Mean Form A SD SEM Mean Form B SD SEM Adult students at a skills center in Tennessee 61 .75 22.3 7.3 3.7 21.9 7.6 3.8 Note. Form A and Form B were administered in counterbalanced order. The time interval between testings was three months. Table 5 presents split-half reliability coefficients and standard errors of measurement for students at a vocational high school in Massachusetts and for applicants for craft apprenticeship programs at a steel plant in Illinois. In computing the split-half reliability coefficients, the halves of the test were formed by assigning alternate passages, rather than alternate items, to each of the halves. This is a more rigorous check of the test’s Copyright © 2006 NCS Pearson, Inc. All rights reserved. 13 reliability. The reliability coefficients are generally high for a power test of reading comprehension. Table 5 IRT Split-Half Reliability Coefficients and Standard Errors of Measurement Sample N Mean Form A SD ra SEM N Mean Form B SD ra SEM Students at a vocational high school in Massachusetts Grade 9 111 23.5 7.0 .84 2.8 103 21.8 7.2 .83 3.0 Grade 10 106 25.6 6.1 .80 2.7 101 25.1 6.0 .79 2.7 Grade 11 70 26.1 6.3 .81 2.7 60 25.2 6.8 .86 2.5 Grade 12 44 25.8 7.6 .90 2.4 37 24.8 6.6 .82 2.8 58 28.7 6.3 .88 2.2 70 28.3 7.2 .92 2.0 Apprentice applicants at a steel plant in Illinois a Split-half coefficients corrected by the Spearman-Brown formula. Evidence of Validity The validity of a test refers to the degree to which evidence supports the interpretation of test scores for their intended purpose. There are three major types of evidence of validity. For the Industrial Reading Test, all three types—content, criterion-related, and convergent/discriminant validity are presented. Evidence of content validity is based on the degree to which the test items adequately represent and relate to the trait or function being measured. Content validity requires systematic examination of the intended subject area and the preparation of exercises and items so that an appropriate sample of this intended content is incorporated into the test. The construction of all IRT passages and items was preceded by an examination of required reading material in selected jobs and training programs. Textbooks and training manuals from actual industrial training programs were used to establish an appropriate content outline and appropriate difficulty levels for passages. Evidence of criterion-related validity is obtained from data that show the statistical relationship between IRT test scores and other measures of performance, such as course grades, training program grades, supervisory evaluations, or job performance measures. This relationship is typically expressed as a correlation coefficient. Table 6 presents correlation coefficients between the IRT and final grades for high school students in vocational training programs. The IRT was administered in early spring and final grades were given in June. Table 7 presents correlation coefficients between the IRT and course grades for high school students in specific vocational training programs. The IRT was administered in early spring and final grades were given in June. Copyright © 2006 NCS Pearson, Inc. All rights reserved. 14 Table 8 presents correlation coefficients between the IRT and various criteria for students in remedial education and vocational skills programs. Table 9 presents correlation coefficients between the IRT and various criteria for industrial groups. In Tables 6 through 9, samples are described in terms of sex and racial composition of the groups, when available. Evidence based on the correlation coefficients support that the IRT is a reasonable predictor of success in both school-based and industrial training programs. Correlations with Other Tests Table 10 presents correlation coefficients between the IRT and various other tests. The data show that the highest correlations tend to be between the IRT and other standardized tests of reading ability, providing evidence of convergent validity for the IRT. Significant correlations were also obtained between the IRT and a variety of other ability measures. The pattern of correlations suggests that, although there is some overlap with other measures of ability such as the Bennett Mechanical Comprehension Test (Bennett, 2006) and the various subtests of the Differential Aptitude Tests for Personnel and Career Assessment (Bennett, Seashore, & Wesman, 1991), there is evidence of discriminant validity. Copyright © 2006 NCS Pearson, Inc. All rights reserved. 15 Table 6 Correlation Coefficients Between the IRT and Final Grades of High School Students in Vocational Training Programs Grade _____IRT____ _____________Criterion______________ Sample Sex Race/Ethnicitya Level Mean Descriptionb Mean N SD r SD Students in various technical training programs at three vocational high schools in eastern Pennsylvaniac Mostly male Mostly male Mostly male Not reported Not reported Not reported 10 11 12 302 241 76 23.6 23.5 25.6 6.9 7.2 6.9 .21** .11 .15 Final grade Final grade Final grade 3.3 0.9 3.4 0.9 3.8 0.9 Students in various technical training programs at three vocational high schools in central Pennsylvaniac Male Male Male White Mostly white White 10 11 12 67 148 82 25.6 27.5 25.5 6.3 6.0 6.7 .40** .33** .39** Final grade Final grade Final grade 3.1 1.0 3.5 0.9 3.4 0.8 Students in various technical training programs at a city vocational high school in central Pennsylvania Mostly male Minority 10 64 17.8 7.0 .38 .32** Final grades: English Vocational course 2.9 1.1 2.6 1.1 .30 .50** Final grades English Vocational course 2.9 1.1 ** Male 14 white, 23 minority 11 21.2 8.6 28.2 29.6 5.3 4.9 .30** .23* Final grade d Final grade 3.4 2.3 3.6 1.1 0.9 0.9 268 24.4 7.3 .34** Final gradef 7.3 7.0 10– g 12 62 27.6 6.4 .34** Final grade 3.3 1.0 White 11 96 26.3 6.8 .31** Final examination grade 74.5 12.4 Male White 12 84 25.5 6.7 .39** Final examination grade 68.9 11.8 Male White 10– 12g 78 25.6 6.6 .53** .50** Final examination grade Final course grade 72.1 79.0 12.2 6.9 Students in various technical training programs at a vocational high school in western Pennsylvania Mostly male Mostly male Mostly white Mostly white 11 12 Students in various technical training programs at a vocational high school in West Virginia Mostly male Mostly white 10– 12e Students in various technical training programs at a vocational school on the Gulf Coast of Florida Mostly male Not reported First-year students in various twoyear technical training programs at two vocational high schools in upstate New Yorkc Male Second-year students in various twoyear technical training programs at two vocational high schools in c upstate New York Students in various technical training programs at a third vocational high school in upstate New York Copyright © 2006 NCS Pearson, Inc. All rights reserved. 37 16 101 86 Table 6 Correlation Coefficients Between the IRT and Final Grades of High School Students in Vocational Training Programs (continued) Grade Sample a Sex Students in various technical training programs at a cooperative vocational high school in New York State Students in various technical training programs at a vocational high school in Massachusetts _____IRT____ ____________Criterion_____________ Race/Ethnicity Mostly male Mostly male Not reported Not reported Level N 10 140 11 139 Mostly male Not reported 9 Mostly male Not reported 10–12 * e Descriptionb Mean SD ** Final grade 3.2 1.1 ** .22 Final grade 3.4 1.0 .12 .24** Final grades:f Shop Related instruction 8.1 8.2 2.1 2.6 Final grades:f Shop Related instruction 8.6 7.2 2.2 2.9 Mean SD r 24.5 7.5 .25 26.5 6.8 195 22.5 7.4 432 25.3 6.6 ** .29 .43** Significant at p <.05 level. Significant at p <.01 level. a Minority includes Black/African-American and Hispanic/Latino(a). b Unless otherwise indicated, the criterion descriptions of “Final grade” and “Final examination grade” refer specifically to vocational courses (and not to other subjects) and are for the last term completed. Unless otherwise indicated, when letter grades were provided, they were converted to a numerical scale ranging from 1 (F) to 5 (A). c The schools belong to the same school district and use the same grading system. Similar distributions of IRT scores for comparable groups of students at each school permitted the presentation of combined validity data. d Letter grades were converted to a numerical scale ranging from 1 (D) to 4 (A). e Preliminary statistical analysis showed no significant increase in mean IRT score from grade 10 to grade 12, and a similar relationship between IRT scores and course grades across grade levels. Therefore, validity data were combined across grade levels. f Letter grades were converted to a numerical scale ranging from 1 (F) to 13 (A+). g Due to the small sample size, analysis of the data by grade level was not technically feasible. ** Copyright © 2006 NCS Pearson, Inc. All rights reserved. 17 Table 7 Correlation Coefficients Between the IRT and Final Grades of High School Students in Specific Vocational Training Programs ______________Criterion_____________ Grade ____IRT____ Program/Sample Sex Race/Ethnicitya Level Mean Descriptionb Mean N SD r SD Metal-Machining Programs Machine Shop Students at three vocational high c schools in central Pennsylvania Students at a vocational high school in Massachusetts Male Mostly white 10–12d 66 27.5 5.1 Male Not reported 10–12 d 52 26.9 5.6 .29* 3.2 1.0 Shop 9.0 2.4 Related instruction 7.6 2.6 3.2 0.8 .40 .61** Final grades: Shop Related instruction 7.7 5.4 2.7 3.4 Final grades:e .20 ** .37 Students at two vocational high schools in eastern Pennsylvaniac Metalworking Programs Metal Fabrication Students at a vocational high school in Massachusetts Mechanical Repairing Programs Aircraft Mechanics Students at a vocational high school in western Pennsylvania Auto Mechanics Students at a vocational high school in western Pennsylvania Agricultural Mechanics, Auto Mechanics Students at a vocational high school in upstate New York Agricultural Mechanics, Auto Mechanics, Machine Trades Students at a vocational high school in upstate New York Air Conditioning, Heating and Refrigeration, Auto Mechanics, Aviation Maintenance Students at a cooperative vocational high school in New York State Copyright © 2006 NCS Pearson, Inc. All rights reserved. Male Not reported 10 33 22.9 5.3 Male Not reported 10–12d 37 24.4 7.8 Final grade .40* Final grade e * Male Mostly white 12 40 30.7 4.4 .44** Final grade 3.4 0.9 Mostly male Mostly white 11 54 27.4 5.2 .46** Final gradef 1.9 0.7 Male White 11 30 26.3 7.3 .67** Final examination grade 78.6 11.5 Male White 10–12d 33 26.0 7.1 .69** ** .64 Final examination grade Final course grade 70.0 81.4 14.5 7.7 Male Male Not reported Not reported 10 11 60 61 24.3 27.5 7.4 6.2 .12 .34** Final grade Final grade 2.8 3.4 1.0 1.1 18 Table 7 Correlation Coefficients between the IRT and Grades in Specific Vocational Training Programs for High School Students (continued) Grade ___ IRT____ ______________Criterion_____________ Program/Sample Sex Race/Ethnicitya Level Mean Descriptionb Mean N SD r SD . Mechanical Repairing Programs (continued) Auto Mechanics, Heating and Ventilation Male Mostly white 10–12d 60 25.6 6.4 .55** Final grade 3.5 0.8 Students at three vocational high c schools in central Pennsylvania Auto Mechanics; Diesel Mechanics; Heating, Ventilation, and Air Conditioning; Recreational Vehicles Students at a vocational high school in Massachusetts Auto Mechanics, Engine Rebuilding, Mechanical Maintenance Students at two vocational high c schools in eastern Pennsylvania Metal Fabrication And Welding Programs Welding Students at two vocational high schools in upstate New Yorkc Male Not reported Male Male Not reported Not reported Male Body and Fender, Welding Students at a vocational high school in West Virginia Auto Body, Sheet Metal, Welding Students at a vocational high school in eastern Pennsylvania Electrical Assembly, Installing, and Repairing Programs Electronics Students at a vocational high school in western Pennsylvania Copyright © 2006 NCS Pearson, Inc. All rights reserved. 10–12 g 116 23.7 e 6.9 .30 ** .40 Final grades: Shop Related instruction 8.4 7.2 1.9 2.3 3.5 3.6 1.0 0.9 70.3 10.0 ** 10 11 90 76 23.0 23.3 6.5 7.7 .15 .03 Final grade Final grade White 11–12d 33 25.5 7.6 .38* Final examination grade Male Mostly white 10–12 d 75 22.8 7.5 .13 Final gradee 7.4 2.2 Male Not reported 11 40 22.0 7.0 .16 Final grade 3.2 0.9 Male Mostly white 11 32 29.1 5.5 .01 Final grade f 3.2 0.8 19 Table 7 Correlation Coefficients Between the IRT and Grades in Specific Vocational Training Programs for High School Students (continued) Grade ____IRT____ ______________Criterion_____________ Program/Sample Sex Race/Ethnicitya Level Mean Descriptionb Mean N SD r SD Electrical Assembly, Installing, and Repairing Programs (continued) Electronics, Industrial Electricity Students at a vocational high school in West Virginia Male Mostly white 10–12 d 45 29.9 5.3 Electronics, Electromechanics Students a vocational high school in Massachusetts Male Not reported 10–12d 43 29.7 5.1 Basic Electricity, Basic Electronics Students at three vocational high schools in eastern Pennsylvaniac Male Not reported 10 58 28.2 Male Not reported 11–12d 42 Male Not reported 10–12d Male White Male Not reported Male Construction Electricity, Industrial Electricity Students at three vocational high c schools in eastern Pennsylvania Electricity, Trade Electricity Students at a cooperative vocational high school in New York State Construction Trade Programs Carpentry Students at three vocational high schools in central Pennsylvaniac Students at a cooperative vocational high school in New York State Carpentry, Masonry Students at a vocational high school in West Virginia Carpentry, Masonry, Plumbing Students at a vocational high school in Massachusetts Copyright © 2006 by NCS Pearson, Inc. All rights reserved. Final gradee 7.9 2.5 .39 ** .49 Final grades:e Shop Related instruction 8.7 7.7 2.3 2.6 5.7 .13 Final grade 3.5 0.8 27.3 5.5 .22 Final grade 3.5 0.8 45 26.6 5.5 .32* Final grade 3.4 0.9 10–12d 57 27.6 6.0 .47** Final grade 3.6 0.9 10–12 d 33 22.2 7.7 .27 Final grade 3.5 1.1 Mostly white 10–12d 50 22.7 7.1 .42** Final gradee 7.3 2.1 Mostly male Not reported 10 35 22.7 7.2 .35* .50** Final grades: Shop Related instruction 8.7 6.6 1.5 3.7 Male Not reported .17 .53** Final grades: Shop Related Instruction 9.7 7.9 1.4 3.1 20 11 30 25.1 .55** ** e e 5.3 Table 7 Correlation Coefficients Between the IRT and Grades in Specific Vocational Training Programs for High School Students (continued) Grade _____IRT____ ____________Criterion_____________ Program/Sample Sex Race/Ethnicitya Level Mean Descriptionb Mean N SD r SD Construction Trade Programs (continued) Building Trades, Carpentry, Masonry, Plumbing Students at two vocational high schools in eastern Pennsylvaniac Male Male Not reported Not reported * 10 11 77 41 20.6 21.8 7.1 7.1 .08 .14 Final grade Final grade 3.0 3.2 0.9 1.0 Significant at p <.05 level. Significant at p <.01 level. a Minority includes blacks Black/African-American and Hispanic/Latino(a). b Unless otherwise indicated, when letter grades were provided, they were converted to a numerical scale ranging from 1 (F) to 5 (A). c The schools belong to the same school district and use the same grading system. Similar distributions of IRT scores for comparable groups of students at each school permitted the presentation of combined validity data. d Due to the small sample size, analysis of the data by grade level was not technically feasible. e Letter grades were converted to a numerical scale ranging from 1 (F) to 13 (A+). f Letter grades were converted to a numerical scale ranging from 1 (D) to 4 (A). g Preliminary statistical analysis showed no significant increase in mean IRT score from grade 10 to grade 12, and a similar relationship between IRT scores and course grades across grade levels. Therefore, validity data were combined across grade levels. ** Copyright © 2006 NCS Pearson, Inc. All rights reserved. 21 Table 8 Correlation Coefficients Between the IRT and Criteria for Students in Special Remedial and Vocational Programs _____IRT____ ___________Criterion_ Mean Descriptionb Program/Sample Sex Race/Ethnicitya N SD r Adult students in an individualized instruction program at a vocational center in California Adult students in technical programs at a skills center in Tennessee Adult students in technical programs at a vocational institute in Florida Adult students in electrical assembling, installing, and repairing programs at a vocational institute in Florida Students in CETA (Comprehensive Employment Training Act) programs in upstate New York 69 male, 18 female 41 white, 46 minority 87 21.9 8.5 .30 Course gradesb 3.0 0.9 22 male, 17 female 19 white, 20 minority 39 24.8 7.1 .30 Teachers’ evaluationsc 3.8 1.4 4/5 male, 1/5 female Minority 113 22.8 6.9 .14 Teacher’s evaluation of learning rated 3.2 1.0 4/5 male, 1/5 female Minority 101 22.9 7.0 .18 Class rank 2.6 1.0 Mostly male Mostly white 140 28.4 6.3 .20*f Completion of course vs. withdrawal or failure — — Mostly male Mostly white 108 28.9 6.1 .24 Final gradeg 3.8 0.8 g 3.7 1.0 5.8 5.4 5.5 5.6 2.1 2.1 2.2 2.3 h Mostly male Mostly white 29 31.0 5.8 45 male, 50 female Mostly white 95 23.6 8.0 ** ___________ Mean SD * ** .66 * .24 .22* * .24 .24* * e Final grade Instructors’ ratings:i Ability to learn Communication skills Progress in training Likelihood of job success Significant at p <.05 level. Significant at p <.01 level. a Minority includes Black/African-American and Hispanic/Latino(a). b Letter grades were converted to a numerical scale ranging from 1 (D) to 4 (A). c Teachers’ evaluations were coded on a 5-point scale ranging from 1 (poor) to 5 (excellent). d Learning rate was coded on a 5-point scale ranging from 1 (very slow) to 5 (very fast). e Class rank was coded on a 4-point scale corresponding to the particular quartile indicated for a student. Top (or first) quartile was coded 4, second quartile was coded 3, third quartile was coded 2, and bottom (fourth) quartile was coded 1. f Point-biserial r. g Letter grades were converted to a numerical scale ranging from a (F) to 5 (A). h A subgroup of the sample of 108. I Students were rated on each factor separately on a scale of 1–10. ** Copyright © 2006 NCS Pearson, Inc. All rights reserved. 22 Table 9 Correlation Coefficients Between the IRT and Criteria for Industrial Groups ____IRT____ Mean Program/Sample Sex Race/Ethnicitya N SD Service technician trainees at a technical training center in Virginia Utility operator trainees at a southern utility Mostly male Mostly male Mostly white Mostly white 133 203 33.9 34.0 3.6 3.4 Mostly male Mostly white 72 34.1 2.4 Mostly male Mostly white 50 34.8 r .11 .16* .33** .38** .27* 1.6 .06 .02 Health physics technicians in a training program at a southern utility Male Apprentices in a construction union in the Northeast Male Mostly white ½ white, ½ minority 24 56 33.2 30.6 2.6 5.3 .70** .53** .24 .31 .50* * .27 .52** * _ _________ __Criterion_ Descriptionb ________ Mean SD Supervisory ratingsb Productivity of machine between service calls Course grades: Systems and components-general Systems and components-specific Mathematics Course grades: Nuclear preparation Nuclear fundamentals Final grades obtained in four training modules: Introduction to the company Systems and components Introduction to health physics Basic health physics Average grade – all four modules Percentile rank of ratings on a work sample Job knowledge test 3.5 88.2 0.5 44.3 94.8 84.5 89.6 4.1 6.3 6.9 85.6 85.3 5.6 5.7 94.1 89.3 78.3 85.5 86.8 50.1 4.0 8.4 9.2 6.2 5.7 28.8 17.7 4.8 Significant at p <.05 level. ** Significant at p <.01 level. a Minority includes Black/African-American and Hispanic/Latino(a). b Mean of last three performance appraisals. Performance was rated on a scale from 1 (low) to 5 (high). Copyright © 2006 NCS Pearson, Inc. All rights reserved. 23 Table 10 Correlation Coefficients Between the IRT and Other Tests Test Sample N _____IRT_____ Mean SD __Other Test__ Mean SD r Bennett Mechanical Comprehension Test, Form S Apprentice applicants at a steel plant in Illinois Apprentice applicants at a steel plant in Indiana 143 33 27.4 30.5 7.5 4.8 .67 .37* ** 40.9 46.1 11.9 8.2 Bennett Mechanical Comprehension Test, Form T Technical workers at an oil refinery in the South 83 29.5 5.4 .38** 46.4 9.1 Differential Aptitude Tests, Form S Verbal Reasoning (VR) Numerical ability (NA) VR + NA Abstract Reasoning Clerical Speed and Accuracy Mechanical Reasoning Space Relations Spelling Language Usage Students in grades 10–12 at a cooperative vocational high school in New York 159 22.8 7.1 .55 .51** .59** .40** –.03 ** .34 .34** .47** ** .54 ** 20.3 16.8 37.1 29.8 47.1 42.9 25.9 58.4 25.4 10.5 7.8 16.6 9.9 17.2 10.3 10.6 16.8 10.0 Differential Aptitude Testsb Verbal Reasoning (VR) Numerical ability (NA) VR + NA Abstract Reasoning Clerical Speed and Accuracy Mechanical Reasoning Space Relations Spelling Language Usage Students in grades 10–12 at three cooperative vocational high school in eastern Pennsylvania Differential Aptitude Tests, Form T Numerical Ability Apprentice applicants at a steel plant in Illinois Applicants for apprentice training at a construction union in the Northeast Mechanical Reasoning Space Relations Copyright © 2006 NCS Pearson, Inc. All rights reserved. 24 908 908 908 485 764 850 843 768 764 23.7 23.7 23.7 23.5 23.7 23.7 23.8 23.7 23.7 7.0 7.0 7.0 7.1 7.0 7.0 7.0 7.1 7.0 .48** .39** .50** .33** .12** .28** .24** .32** .41** 20.9 17.3 38.2 31.6 42.0 42.3 27.4 54.9 23.5 8.4 6.4 13.0 8.8 13.5 9.8 10.6 16.3 8.2 143 56 27.4 30.6 7.5 5.3 .73** 20.1 10.8 .16 .30** 59.7 43.3 6.6 10.7 Table 10 Correlation Coefficients Between the IRT and Other Tests (continued) Test Differential Aptitude Tests, Form A Numerical Ability Minnesota Clerical Test Names Numbers Personnel Tests for Industry, Form A Verbal Numerical Revised Minnesota Paper Form Board Test Sample N _____IRT_____ Mean SD Utility operator and technician trainees at a southern utility 75 34.1 2.4 Utility operator and technician trainees at a southern utility 75 34.1 2.4 Utility operator and technician trainees at a southern utility 100 33.9 143 27.4 7.5 Basic Occupational Literacy Test Reading Vocabulary Reading Comprehension Arithmetic Computation Arithmetic Reasoning Adult students at a skills center in Tennessee 116 22.4 6.7 California Achievement Tests, Form A and B Reading Mathematics Language California Test of Mental Maturity Students in CETA (Comprehensive Employment Training Act) programs in upstate New York Gates–MacGinitie Reading Tests: Survey F, Form 2M Comprehension Short Form Test of Academic Aptitude Language Nonlanguage Total Reading for Understanding Placement Test Copyright © 2006 NCS Pearson, Inc. All rights reserved. 24.6 329 25.4 6.8 Adult students at a vocational institute in Florida Adult students at a vocational center in California Students in CETA (Comprehensive Employment Training Act) programs in upstate New York 168 87 90 27.8 21.6 24.7 6.5 8.4 7.7 Adult student at a skills center in Tennessee 182 25 31.1 5.0 .12 .03 117.8 115.7 19.9 24.3 .16 ** .28 .58** 42.0 23.8 37.1 4.3 3.0 11.6 .56** .57** ** .30 ** .46 108.9c 121.0 c c 107.0 c 108.3 16.0 c 16.4 c c 15.7 c 18.4 .83** .42** .70** .58** 10.4d 9.3 d 9.2 d 41.6 2.9 d 3.4 d 3.0 d 10.6 .79** .70** 10.9 d 9.1 d 2.7 d 4.1 d ** 100.6e 94.1 e 97.5 e 88.3 15.2 e e 14.5 14.6 e 21.7 8.0 Students at three vocational high schools in upstate New York 22.3 .16 2.5 Apprentice applicants at a steel plant in Illinois 94 __Other Test__ Mean SD r 7.0 .73 ** .69 .78** .65** Table 10 Correlation Coefficients Between the IRT and Other Tests (continued) Test Wide Range Achievement Test, Level 2 Arithmetic Computation Ohio Trade Tests Sample Adult students at a vocational institute in Florida _____IRT_____ Mean SD r 168 27.8 6.5 .58** 40 49 45 28.9 25.8 22.9 7.1 6.2 7.0 .60** .67** .63** _ Other Test__ Mean SD 7.6d 2.2d Students at three vocational high schools in Pennsylvania and one in West Virginia Basic Electronics Achievement Machine Trades Achievement Welding Achievement * Significant at p <.05 level. Significant at p <.01 level. a Means and standard deviations are expressed in raw scores, unless otherwise indicated. b Form unknown. c Standard scores. d Grade equivalents. e IQ scores. ** Copyright © 2006 NCS Pearson, Inc. All rights reserved. N 26 126.2 139.9 109.9 37.5 39.0 25.9 References Anastasi, A. & Urbina, S. (1997). Psychological testing (7th ed.). Saddle River, NJ: Prentice Hall. Bennett, G. K. (2006). Bennett Mechanical Comprehension Test manual. San Antonio, TX: Harcourt Assessment, Inc. Bennett, G. K., Seashore, H. G., & Wesman, A. G. (1991). Differential Aptitude Tests for Personnel and Career Assessment technical manual. San Antonio, TX: Harcourt Assessment, Inc. Dale, E., & Chall, J. S. (1948). A formula for predicting readability. Educational Research Bulletin, 27, 11–20, 37–54. Powers, R. D., Sumner, W. A., & Kearl, B. E. (1958). A recalculation of four readability formulas. Journal of Educational Psychology, 49, 99–105. Society for Industrial and Organizational Psychology. (2003). Principles for the validation and use of personnel selection procedures (4th ed.). Bowling Green, OH: Author. U.S. Department of Labor. (1977). Dictionary of occupational titles (4th ed.). Washington, D.C.: U.S. Government Printing Office. U.S. Department of Labor. (1978). Occupational outlook handbook. Washington, D.C.: U.S. Government Printing Office. Copyright © 2006 NCS Pearson, Inc. All rights reserved. 27