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solves the problems in a di erent order than the instructions specify but does not complete all items in the subtest, the validity of the results may be compromised and should be interpreted with caution. Order of administration is important, because item di culty varies within each subtest, so following a di erent order may result in exposure to a subset of items before the time limit is reached that di ers in di culty from the subset of items that would have been administered according to the standard order. If the examinee solves the problems in a di erent order than the instructions specify but completes all items in the subtest before the time limit, the validity of the results should not be a ected.

HOW TO SCORE THE WIAT-III

The WIAT-III yields several types of scores: raw scores, standard scores, grade equivalents, age equivalents, and percentile ranks. Raw scores reflect the number of points earned by the examinee on each subtest. These scores, by themselves, are meaningless because they are not norm-based. Converting raw scores to standard scores, which are norm-based, allows the examinee’s performance to be compared to that of others.

The WIAT-III standard scores have a mean of 100 and a SD of 15. The theoretical range of standard scores for the subtests and composites is 40 to 160, although the actual standard score ranges for certain subtests do not span the full theoretical range due to floor or ceiling limitations (refer to the Min & Max WIAT-III Sub-

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test Scores file in the online Digital Resources for actual score ranges by subtest). An important theoretical assumption is that achievement test performance is distributed on a normal curve, with the majority of examinees scoring within +/– 1 SD of the mean. Thus, about two-thirds (68%) of examinees score in the range of 85 to 115. Less than 3% of examinees score above 130 or below 70. Generally, standard scores or percentile ranks should be used when comparing performance on one WIAT-III subtest with another, one composite to another, and when comparing WIAT-III results to performance on another norm-referenced test.

Items are objectively scored as correct (1 point) or incorrect (0 points) for a majority of the WIAT-III subtests: Listening Comprehension, Early Reading Skills, Math Problem Solving, Word Reading, Pseudoword Decoding, Numerical Operations, the Expressive Vocabulary component of Oral Expression, Spelling, and each of the Math Fluency subtests. A set of scoring rules, which employ subjective judgment, must be applied to score the remaining subtests.

Types of Scores

Considerations for calculating and using each type of score in the WIAT-III are provided in this section. Each of the subtest raw scores is converted to age-based or grade-based derived scores, including standard scores, percentile ranks, age or grade equivalents, normal curve equivalents, and stanines. Growth scale values

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are also available. An overview of each type of score included in the WIAT-III is provided in Rapid Reference 3.4.

Rapid Reference 3.4

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Types of Scores in the WIAT-III

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The following scores are commonly used for group reporting but are rarely used for individual assessments.

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Raw Scores and Weighted Raw Scores

Subtest raw scores are calculated in a variety of ways.

•For hand scoring, methods for calculating raw scores and weighted raw scores are summarized in Table 3.6.

•Using Q-global or the Scoring Assistant, fewer steps are required for calculating raw scores. For subtests that use weighted raw scores, enter the raw scores only. The raw score entry screen for Q-global is shown in Figure 3.3. Raw scores will be automatically converted into weighted raw scores when calculating derived scores. Methods for calculating raw scores using Q-global are summarized in Table 3.7.

•Using Q-interactive, raw score calculation is automatic for every subtest once items are scored by the examiner. Refer to Chapter 7 for information about Q-interactive.

Standard Scores

To be meaningfully interpreted, the raw scores or weighted raw scores of the WIAT-III must be converted to standard scores. The norms are reported within various age or grade bands, as shown in the Don’t Forget box.

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Norms are grouped into larger age or grade bands for older examinees and adults for whom academic growth progresses at a slower rate. If grade-based scores are selected, the scores are based upon semester (fall, winter, or spring) norms for grades Pre-K through 12.

If age-based scores are selected, the scores for ages 4 to 13 years are reported in 4-month intervals. The scores for ages 14 to 16 years are reported in 12-month (annual) intervals. The scores for high school examinees aged 17 to 19 years are based upon one 3-year age band norm. The age bands increase up to age 50.

Age and Grade Norm Bands

When converting from raw to standard scores, you must first decide whether to use age-based or grade-based norms. For examinees who have graduated high school, only age norms are provided. Selecting age-based or grade-based scores determines the peer group with which the examinee’s performance is compared, and the decision is influenced by a number of di erent factors, such as whether a particular skill develops

according to age (i.e., developmental skills) or grade (i.e., curriculum-based skills), whether an examinee is outside of the typical age range for his or her grade level, and district/agency/state requirements. For example, some settings may require the use of age-based scores when evaluating for a specific learning disability. Many examiners compute both age-based and grade-based scores in order to compare them.

Don’t Forget

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Tips for Navigating the Digital Technical Manual

Use the hypertext (text with hyperlinks). All of the text included in the Quick Links and Table of Contents pages at the front of the manual contain hyperlinks, which means you can click a line of text with your cursor and the document will

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immediately advance to the page that includes the selected content. These hyperlinks are the fastest way to find a specific chapter, section, table, or figure. For example, in the following image, clicking “Table 1.2” will advance the document to page 15.

Use the Main TOC button. A button appears in the bottom right corner of every page that reads “MAIN TOC.” This is a home button that will move the document back to the Table of Contents at the beginning of the manual. This button is designed to help the reader move through the manual quickly and efficiently.

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Use the search function. PDF readers include a search function that is enabled by typing Ctrl+F (the Ctrl key and the F key at the same time on a PC or

Command+F on a Mac). This box allows you to search for a word or phrase that appears anywhere in the manual. This is the best way to find specific content that may not be called out in the Table of Contents. For example, in the following image, searching “test-retest” and then selecting “Next” or the left or right arrow will show each instance that test-retest is referenced in the manual.

Select a row of numbers. When reading data tables on screen, some people find it difficult to visually track across a row of numbers without losing their place.

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One helpful tip is to select the row of numbers with your mouse to highlight the data on screen.

Enlarge the font. Remember that you can zoom in and out by clicking the plus or minus sign at the top of the navigational menu, making the size of the font bigger or smaller, when viewing the digital manual. You can also enlarge the font (zoom in) by selecting a larger percentage in the size box. Zoom in with keyboard shortcuts on a PC by using the Ctrl+equal sign (for Mac use Command+equal sign) and zoom out using Ctrl+hyphen on a PC or Command+hyphen on a Mac.

Rotate the page. Some PDF readers will automatically rotate the page to a portrait or landscape orientation, as needed. However, you can do this manually as well by typing the following three keys at the same time: Shift, Ctrl, +.

Print. You have the option to print the pages or tables in the digital manual that you use most frequently.

Additional Keyboard Shortcuts. Adobe Acrobat provides additional help on their keyboard shortcuts online at helpx.adobe.com/acrobat/using/keyboard-shortcuts

.html.

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In most cases, age and grade based standard scores will be similar. However, important di erences can occur if the student has been retained or has received an accelerated grade placement, or if the student began school earlier or later in the year than is typical. In these cases, the grade-based norms are probably more relevant. The Don’t Forget box provides further information about selecting and reporting age-based and grade-based standard scores.

When achievement scores are compared with scores on ability or language tests, age-based norms are recommended to quantify examinee performance on the achievement measure. However, with the WIAT-III as well as other measures of academic achievement, there are times when age-based scores can be misleading. For example, when an examinee has been retained in a grade, comparing him or her to age-mates assumes that the equivalent instructional opportunity has been provided. In such a case, the individual might have lower scores because some skills have not been taught. For this reason, grade-based scores are typically preferred for examinees who have repeated or skipped grades. Especially when communicating results to teachers and parents, discussing how the examinee is performing academically in relation to others in the same grade is typically easier to interpret.

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C A U T I O N

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Students Who Are Young or Old for Grade

Grade norms must be used to obtain scores for certain subtests and composites when an examinee’s age is out of level. If an examinee is unusually young or old for his or her grade, age norms may not be available for all subtests or composites. For example, age norms are not available for a 7-year-old third grader who is administered the Essay Composition subtest (administered to grades 3–12), because this examinee’s age is considered unusually young (out of level) for third grade. However, it is possible to yield age norms for this examinee for subtests such as Listening Comprehension and Oral Expression, because these subtests are administered at every age and grade.

Descriptive Categories

When the WIAT-III was published in 2009, a 15-point classification system for reporting scores was suggested. When the KTEA-3 published in 2014, a choice between a 10-point and 15-point classification system was o ered. Both systems divide the theoretical standard score range111111111 of 40 to 160 into seven categories, but one uses 10-point ranges and the other uses 15-point ranges. The same classification systems and descriptive categories suggested for the KTEA-3 may be considered for the WIAT-III. These options are summarized in the Don’t Forget box. The same considerations described in the KTEA-3 chapter for choosing between the classification systems are applicable to the WIAT-III as well.

As shown in the Don’t Forget box, the qualitative descriptors suggested for the WIAT-III at the time of its publication include the terms superior and very superior, which are now considered to be value-laden terms that are best avoided. Using neutral terms that simply describe the score’s distance from the mean (such as low, average, high) are currently preferred for all clinical assessment instruments.

Your decision to use the 15-point or the 10-point classification system and the qualitative descriptors you choose may be influenced by the examinee’s score profile, the other tests you’ve administered, personal preference, and reporting requirements you’ve been given by outside agencies, among other things. When reporting similar standard scores across di erent instruments, consider using the classification system suggested by the cognitive measure. When reporting results from the WIAT-III and the WISC-V, for example, it would be reasonable to use the 10-point scale described in the WISC-V manual (shown in the Don’t Forget box) to describe standard scores across both tests.

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Don’t Forget

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Options for Descriptive Category Systems

10-Point System

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Qualitative Descriptors Are Suggestions

Qualitative descriptors are only suggestions and are not evidence-based. You may use alternate terms as appropriate.

Growth Scale Values

Growth Scale Values (GSVs) are designed for measuring change and are based on the Item Response Theory (IRT) ability scale. In the same way that “inches” are an

174 ESSENTIALS OF KTEA™-3 AND WIAT®-III ASSESSMENT

equal-interval scale of length, the GSV scale is an equal-interval scale of academic skill. Thus, GSVs can be used as a “yardstick” by which academic progress can be measured throughout the school years. GSVs reflect absolute performance rather than performance relative to a normative sample, although the examinee’s rate of progress may be compared to the typical growth rate in the normative sample using the GSV Charts report in Q-global.

The degree to which GSVs are able to measure academic learning is limited to the content and skill coverage of the test or subtest. The WIAT-III is not designed to measure all aspects of a student’s curriculum or provide in-depth coverage of all skill categories. Consider curriculum-based or criterion-referenced measures for more comprehensive content and skill coverage.

Don’t Forget

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Using Growth Scale Values

•GSVs are sensitive to small changes in performance across time.

•Comparing, subtracting, and averaging GSVs from the same subtest is encouraged

but not across different subtests.

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•Three or more months between testing sessions is recommended to avoid practice effects.

•Three or more GSV scores are recommended to form a reliable growth trend.

Interpreting GSVs and Standard Scores