Case Study: Marcus
Marcus, age 9 years 8 months, is in the fourth grade and is having some academic difficulties in school. He was administered the Stanford Achievement Test, Tenth Edition (Stanford 10). Based on Marcus’ scores on the summary report, answer the following questions:
Stanford 10 Student Summary Report
National Grade Percentile Bands
Subtests and Total Number Possible Number Correct Scaled Score National PR-S* National NCE Grade Equivalent AAC Range 1 10 30 50 70 90 99
Total Reading 114 82 639 59-5 54.8 5.4 Middle
Total Mathematics 80 29 629 22-3 33.7 3.3 Low
Language 48 28 610 39-4 44.1 3.5 Middle
Spelling 40 30 647 73-6 62.9 6.4 High
Science 40 12 619 18-3 30.7 2.8 Low
Social Science 40 22 607 40-5 44.7 3.5 Middle
Listening 40 22 608 35-4 41.9 3.4 Middle
Complete Battery 402 270 NA 56-5 53.4 5.0 Middle
*PR-S: Percentile Rank and Stanine
1. Interpret the percentile ranks (PR) for each of the subtests and total score.
2. Interpret the stanine scores (S) for each subtest and total score.
3. Across subtest and total scores, identify Marcus’ relative strengths and weaknesses based on his stanine (S) scores.
4. The percentile bands provide a graphic display of measurement error. The wider the bands, the more error on the subtests.
a. Which subtest score(s) appear to have the greatest error?
b. Which subtest score(s) appear to have the least error?
5. Marcus’ grade equivalent score on spelling is 6.4. Based on this score, Marcus’ parents believe he is ready for instruction in spelling at the 6th grade level. Do you agree with this? Why or why not?