Understanding Scores on Norm-Referenced Tests: Comprehensive Tests of Basics Skills (CTBS ) California Achievement Test

1. Understanding Scores on Norm-Referenced Tests:Comprehensive Tests of Basics Skills (CTBS)California Achievement Tests (CAT) November 2002

2. What is CTBS? • TerraNova Comprehensive Tests of Basic Skills • A battery of tests in reading, language and mathematics • Designed to provide general measures of the achievement levels of individual children • Norm-Referenced • Provides information that compares a student’s achievement with that of a representative sample

3. CTBS Subtests • Reading • Language • Language Mechanics • Mathematics • Mathematics Computation

4. What Scores Are Reported? • Percentile Ranks • Percent Correct by Objective

5. Percentile Ranks Percentile ranks are reported for each subtest to: • Compare performance to a national norming sample • Compare performance to other children in Montgomery County Public Schools

6. Understanding Percentile Ranks A common way to evaluate a student’s performance is to compare it with the performances of some group. Top of the class Juanito’s results on a reading test places him 74th from the bottom of his class. Juanito, as an example, is a Grade 4 student in a reading class of exactly 100 students. 74th The 74 is a PERCENTILE RANKbecause it represents a relative standing, i.e., it identifies what percentage of Juanito’s classmates scored the same as or lower than him. Because there are 100 students in his group, one can then say that Juanito performed as well as or better than 74 percent of his classmates. Bottom of the class

7. Understanding TerraNova CTBS/CAT Scores MSDE uses the TerraNova Comprehensive Tests of Basic Skills in Grades 2 and 4 and the TerraNova California Achievement Tests (CAT) in Grade 6 to compare Maryland’s students’ performance on these tests with the performances of students nationally. Since both the TerraNova CTBS and the TerraNova CAT were normed using a national norming sample, the percentile ranks associated with these tests and used by MSDE are NATIONAL percentile ranks.

8. Understanding National Percentile Ranks If Juanito had scored at the 74th national percentile rank on the TerraNova CTBS reading subtest: Top of the nation 74th Juanito’s performance in reading equaled or exceeded the performances of 74 percent of Grade 4 students nationally. The TerraNova CTBS was normed using a sample of about 180,000 students from schools randomly selected nationwide. Bottom of the nation

9. Understanding Local Percentile Ranks Even though Juanito scored at the 74th national percentile rank on the TerraNova CTBS reading subtest, he will have a different local percentile rank because he is being compared to a different group of students Top of the county Now, Juanito is only being compared to about 10,000 Grade 4 students in MCPS. 52nd Juanito’s performance in reading equaled or exceeded the performances of 52 percent of Grade 4 students locally. Bottom of the county

10. 1 Percentile ranks do not represent equivalent amounts of achievement along the percentile rank scale. There is a smaller difference in achievement among students in the 45th to 50th percentile ranks than there is among students in the 5th to the 10th (or in the 95th to the 99th) percentile ranks, even though the percentile rank difference in each case is five. 1 20 10 30 40 50 60 70 80 90 99 2 Percentile ranks cannot be averaged. Interpretation of Percentile Ranks In a normal distribution, there is a piling up of scores between the 25th and the 75th percentile ranks and a tailing off at either end. For this reason:

11. Percent Correct by Objective • Percentage of correct answers for each subtest • Shows the results for objectives on each subtest where the objective met the criteria for percent correct analysis • The number of items of the objectives does not always add up to the total number of items for the subtest. Some tested objectives were not included because they had too few items or lacked adequate reliability for meaningful interpretation of the scores • Criteria for Analysis • At least 6 items, or • Reliability of at least .60 • Comparison to National Average/County Average • Indicate areas of strength and need • Guideline to difficulty of the items

12. Objectives Measured on the Reading Subtest • = objective is measured at a particular grade level • a objective met the criteria for percent correct analysis

13. Objectives Measured on the Language Subtest • = objective is measured at a particular grade level • a objective met the criteria for percent correct analysis

14. Objectives Measured on the Language Mechanics Subtest • = objective is measured at a particular grade level • a objective met the criteria for percent correct analysis

15. Objectives Measured on the Mathematics Subtest • = objective is measured at a particular grade level • a objective met the criteria for percent correct analysis

16. Objectives Measured on the Mathematics Subtest (Cont.) • = objective is measured at a particular grade level • a objective met the criteria for percent correct analysis

17. Objectives Measured on the Mathematics Computation Subtest • = objective is measured at a particular grade level • a objective met the criteria for percent correct analysis

18. MCPS Curriculum CTBS Objectives Connections to Instruction • How do the CTBS objectives align with the MCPS Curricular Framework? • Where are the connections?

19. Connections to Instruction • Knowledge and skills required on CTBS are a subset of knowledge and skills found in the MCPS curriculum • Some CTBS knowledge and skills are addressed by MCPS at earlier grades • It is helpful for students to practice the way in which they will be expected to respond on CTBS; therefore, some of the formative assessments found in the MCPS curriculum are designed to align with CTBS

20. Looking at the Home Report

21. Your Child’s National and County Percentile Ranks

22. Objective # Items Correct Total # of Items Percent Correct National Average County Average • Total Reading Subtest • § Basic Understanding • §Analyze Text • §Identifying Reading Strategies 20 7 6 4 25 8 7 6 80 88 86 67 71 78 74 64 82 85 84 75 • Total Language Subtest • §Introduction to Print • §Editing Skills 17 6 7 20 7 7 85 86 100 76 79 76 88 91 89 • Total Language Mechanics Subtest • §Sentences, Phrases, Clauses • §Writing Conventions 19 9 10 20 9 11 95 100 91 67 75 60 78 89 75 • Total Mathematics Subtest • §Numbers and Number Relations • §Computation & Numerical • Estimation 18 4 3 26 6 5 69 67 60 73 85 69 86 95 81 • Total Math Computation Subtest • §Addition • §Subtraction 13 8 5 20 10 9 65 80 56 68 72 64 80 84 73 Your Child’s Percent Correct Scores

23. Consider the Whole Picture Teacher Observation Grades CTBS Classroom Tests Effort