Understanding the Highly Capable Score Report

Technical Appendix for Matrix Scores

How to Understand Your Student’s Highly Capable Scores

Introduction

The Issaquah School District reports scores for Highly Capable testing as a single holistic matrix score. This technical appendix defines key terms, explains how the matrix score is determined using a z-score formula and provides examples of score reports.

For 2nd Grade Families: 21-22 Understanding the 2nd Grade Highly Capable Score Report

Definitions

Standard Score (SS): The Standard Score is based on the student’s raw score, which has been adjusted for age or grade and placed on a scale that makes a comparison with a representative sample of students of the same age or grade. The CogAT uses age based standard scores and the Iowa Achievement Test and Torrance Test of Creative Thinking use grade based standard scores. Standard scores are used to determine the matrix score instead of percentile ranks because standard scores can be normalized. Normalization is a process of adjusting values measured on different scales to a common scale. 

Standard Deviation (SD): The Standard Deviation tells us how far a score is from the average score for a group. A score that is very close to the average score will have a very small standard deviation. A score that is far above the average score will have a large positive standard deviation. A score that is far below the average score will have a large negative standard deviation. A standard deviation ranges from -4.0 to +4.0. 

 

Z-score: Z scores are standard scores which are calculated by a formula that includes the mean (average) of all students in the norm group and the standard deviation (distance from the mean) to create a statistic that is consistent across all tests. 

The formula for calculating z-scores is the student’s standard score minus the mean of the norm group divided by the standard deviation.  The mean of the norm group and the standard deviation are statistics provided by the test vendors. 

Z-scores help to identify students significantly above the average while reducing the risk of a student being eliminated because of one individual criteria.          

Examples:

Standard Score Minus	Mean Standard Score*	Divided by the Standard Deviation*	Equals the z-score	Matrix Score
155 -	100	/16	= 3.43	8
240 -	185	/21.6	= 2.59	7
121 -	111.3	/15.6	= .62	3

*These are sample numbers for the purpose of understanding the formula only.

Matrix Score: Z-scores are converted to a matrix score to determine which students are significantly above the average.  (See the Z-score Conversion Matrix below)  The Final Matrix Scores are totaled to determine the appropriate services.

Z-score Conversion Matrix Table
Z-score	Relation to the Mean of all Scores	Matrix Score Conversion
3.00 and above	A score that is at least 3 standard deviations (SD) above the mean	8
2.5 - 2.99	A score that is between 2.5 SDs above the mean and 3 SDs above the mean	7
2.0 - 2.49	A score that is between 2 SDs above the mean and 2.5 SDs above the mean	6
1.5 - 1.99	A score that is between  1.5 SDs above the mean and 2 SDs above the mean	5
1.0 - 1.49	A score that is between 1 SD above the mean and 1.5 SDs above the mean	4
0.5 - .99	A score that is between ½ SD above the mean and 1 SD above the mean	3
0 - .49	A score that is between the mean and ½ SD above the mean	2
-.01 and below	A score that is below the mean	1

 

 

 

 

 

 

 

 

 

 

 

Weightings: The scores are weighted to balance priorities in ability and achievement for success in the services offered. 

The CogAT is weighted higher (X3) than the Iowa Achievement Test (X2) because this test is intentionally designed to identify students who will be successful in a highly capable program.  Weighting the achievement test slightly less attempts to equitably balance the range of educational experiences of the students. Note that the TTCT assessment is used for grades 2 through 12 only.

Highly Capable Program Selection Criteria

Program	Assessments Used	Matrix Score for Eligibility
PEP	IOWA Math and Reading CogAT Full Battery	80 or greater
SAGE Reading	IOWA Achievement - Reading CogAT Nonverbal CogAT Verbal TTCT Creativity Index	47 or greater
SAGE Math	IOWA Achievement - Math CogAT Nonverbal CogAT Quantitative TTCT Creativity Index	49 or greater
MERLIN	CogAT Verbal CogAT Quantitative CogAT Nonverbal IOWA Achievement Math IOWA Achievement Reading TTCT Creativity Index	84 or greater

 

Sample Score Report ~ CogAT Screener

Below is a sample score report. See the steps listed below to understand how the Weighted Matrix Score is derived.

Test Given	Standard  Score (SS)	Matrix Score	Weighting	Weighted Matrix Score
CogAT Screener	132	6	x3	18
Total Matrix Score Required for Highly Capable Full Testing Eligibility = 20 or greater				Total Matrix Score: 18

 

 

 

 

Step 1: Standard Score is reported from the test vendor

Step 2: The score is converted to a z-score and assigned a matrix score

Step 3: The weighting is calculated to get a final weighted matrix score

Step 4: The total matrix score is used to determine eligibility for full testing

Sample Score Report for Full Testing ~ PEP (K-2)

 

Below is a sample score report. See the steps listed below to understand how the Weighted Matrix Score is derived. 

Test Given	Standard  Score (SS)	Matrix Score	Weighting	Weighted Matrix Score
CogAT Verbal	148	8	x3	24
CogAT Quantitative	135	6	x3	18
CogAT Nonverbal	139	6	x3	18
Iowa: Total Reading (Two Parts)*		8	x2	16
Iowa: Reading	154
Iowa: Vocabulary	152
Iowa:  Total Math	150	8	x2	16
Total Matrix Score Required for Highly Capable Eligibility with services in PEP= 80   Total of all tests.				Total Matrix Score:   92

 

 

 

 

 

 

 

 

 

 

 

 

 Step 1: Standard Scores are reported from the test vendor

Step 2: Each score is converted to a z-score and assigned a matrix score

Step 3: Weightings are calculated and the final matrix scores are added together to get a total weighted matrix score

Step 4: The total matrix score is used to determine eligibility for HCP services

* For Iowa Total Reading the standard scores are reported separately for reading and vocabulary. The converted z-scores are then averaged to determine the matrix score.

Sample Score Report ~ SAGE and MERLIN

Below is a sample score report for a student who qualified for SAGE Math. See the steps listed below to understand how the Matrix Scores for MERLIN, SAGE Reading and SAGE Math are derived.

Test Given	Standard  Score (SS)	Matrix Score	Weighting	Weighted Matrix Score
CogAT Verbal	121	4	x3	12
CogAT Quantitative	140	7	x3	21
CogAT Nonverbal	146	7	x3	21
Iowa: Total Reading* (Two parts)
IOWA: Reading	198	4	x2	8
IOWA: Vocabulary	194
Iowa Achievement Test:  Total Math	207	7	x2	14
Torrance Test of Creative Thinking (TTCT)	116	2	x1	2

 

Total matrix score required for HCP eligibility with services in MERLIN is 84.   This is the sum of all tests.	MERLIN Matrix   Score: 78
Total matrix score required for HCP eligibility with services in SAGE Reading is 47.   This is the sum of the CogAT Verbal, CogAT Nonverbal, Iowa Reading and TTCT.	SAGE Reading Matrix   Score: 43
Total matrix score required for HCP eligibility with services in SAGE Math is 49.   This is the sum of the CogAT Quantitative, CogAT Nonverbal, Iowa Math and TTCT.	SAGE Math Matrix   Score: 58

 Step 1: Standard Scores are reported from the test vendor

Step 2: Each score is converted to a z-score and assigned a matrix score

Step 3: Weightings are calculated and the final matrix scores are added together to get a total weighted matrix score

Step 4: The total matrix score is used to determine eligibility for HCP services

* For Iowa Total Reading the standard scores are reported separately for reading and vocabulary. The converted z-scores are then averaged to determine the matrix score.

Explanation of the Score Report ~ Secondary

Below is a sample score report for a student who qualified for identification in the area of Math. See the steps listed below to understand how the Matrix Scores for secondary qualification in Reading, Math or both areas are derived.

Test Given	Standard  Score (SS)	Matrix Score	Weighting	Final Matrix Score
CogAT Verbal	121	4	x3	12
CogAT Quantitative	140	7	x3	21
CogAT Nonverbal	146	7	x3	21
Iowa: Total Reading* (Two parts)
IOWA: Reading	198	4	x2	8
IOWA: Vocabulary	194
Iowa Achievement Test:  Total Math	207	7	x2	14
Torrance Test of Creative Thinking (TTCT)	116	2	x1	2

 

Total matrix score required for HCP eligibility in Reading is 47.   This is the sum of the CogAT Verbal, CogAT Nonverbal, Iowa Reading and TTCT.	Secondary Reading Matrix   Score: 43
Total matrix score required for HCP eligibility with services in Math is 49.   This is the sum of the CogAT Quantitative, CogAT Nonverbal, Iowa Math and TTCT.	Secondary Math Matrix   Score: 58

 Step 1: Standard Scores are reported from the test vendor

Step 2: Each score is converted to a z-score and assigned a matrix score

Step 3: Weightings are calculated and the final matrix scores are added together to get a total weighted matrix score

Step 4: The total matrix score is used to determine eligibility for HCP services

* For Iowa Total Reading the standard scores are reported separately for reading and vocabulary. The converted z-scores are then averaged to determine the matrix score.