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:

I. 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?

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