Understanding the Highly Capable Score Report
How to Understand Your Student’s Highly Capable Scores
(Also known as the Technical Appendix for Matrix Scores)
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 zscore formula and provides examples of score reports.
ISD uses three assessments to determine Highly Capable Program eligibility:
 CogAT: Cognitive Abilities Test (K12)
 iReady Reading and Math (grades K5) or the IOWA Achievement Test (grades 612)
 TTCT: Torrance Test of Creative Thinking (grades 2  12)
The Matrix Score AtAGlance:
The District uses a zscore formula to convert the standard scores from each test to a common scale. Scores from the three assessments can then be combined for each student into a single holistic matrix score. This approach allows the District to be more precise and equitable in its decisions and supports students who might have a somewhat uneven profile.
Step 1: Use Standard Scores
Step 2: Each score is converted to a zscore and assigned a matrix score 18
Step 3: Calculate weightings to get a total weighted matrix score
Step 4: Use the total matrix score to determine eligibility for various Highly Capable Program services
The Matrix Score in Detail
Step 1: Use the standard score
The Standard Score (SS) 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.
The standard score is used for making the comparisons necessary in the identification process. There is widerange of standard scores with the 99th percentile.
Percentile Rank  Standard Score 
99  160 
99  159 
99  158 
99  157 
99  156 
99  155 
99  154 
99  153 
99  152 
99  151 
99  150 
99  149 
99  148 
99  147 
99  146 
99  145 
99  144 
99  143 
99  142 
99  141 
99  140 
99  139 
99  138 
99  137 
99  136 
99  135 
Step 2: Each score is converted to a zscore and assigned a matrix score 18
Zscores 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 Standard Deviation (SD) 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.
The formula for calculating Zscores 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.
Zscores 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 zscore 
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.
Step 3: Calculate weightings to get a total weighted matrix score
Zscores are converted to a matrix score to determine which students are significantly above the average. (See the Zscore Conversion Matrix below). The Final Matrix Scores are totaled to determine the appropriate services.
Zscore Conversion Matrix Table 

Zscore 
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 
Are the Scores Weighted?
The scores are weighted to balance priorities in ability and achievement for success in the services offered. Weightings are given to the measures according to their value in predicting success in the Highly Capable Program. The CogAT is weighted X3 and the iReady or Iowa X2 and the TTCT X1. 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.
Step 4: Use the total matrix score to determine eligibility for various Highly Capable Program services
Highly Capable Program Selection Criteria
Program 
Assessments Used 
Matrix Score for Eligibility 
PEP 
iReady Math and Reading CogAT Full Battery 
80 or greater 
SAGE Reading 
iReady Achievement  Reading CogAT Nonverbal CogAT Verbal TTCT Creativity Index 
47 or greater 
SAGE Math 
iReady Achievement  Math CogAT Nonverbal CogAT Quantitative TTCT Creativity Index 
49 or greater 
MERLIN 
CogAT Verbal CogAT Nonverbal CogAT Quantitative iReady Achievement Math iReady Achievement Reading TTCT Creativity Index 
84 or greater 
Sample Score Reports
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 Zscore 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 (K2)
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 
iReady Reading 
154 
8 
x2 
16 
iReady 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 zscore 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
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 
iReady Reading  198  4  x2  8 
iReady 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 Zscore 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
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 Zscore 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 Zscores are then averaged to determine the matrix score.