Test scores provide an estimate of your child’s performance in the area measured by the test. So, if the test purports to measure spelling, the test score will give you an estimate of your child’s performance (on that test) in spelling. The accuracy of your child’s score on that test depends on many factors including
- the child’s health and well-being,
- feelings about being tested that day
- the strength of the test to measure the attribute it purports to measure,
- environmental factors such as lighting and warmth in the room,
- Any limitations of the administrator of the test or of the person taking the test.
- And any language differences (which may be cultural), etc.
Why administer special tests to measure factors the teacher already understands about my child?
One source of information is never sufficient for understanding a child’s performance. Test scores provide additional information to support what the classroom teacher is finding in school. The more information available the more likely it is that relevant services and supports can be implemented to facilitate your child’s academic success.
Test scores provide helpful information for problem solving and decision-making.
What do all the different scores mean?
Raw Scores report the number of items answered correctly on a given test or sub test.
Because of differences in tests (number of total items, types of scoring procedures, frequency of use, etc.), it is difficult to compare raw scores from one test to another.
Let’s say your child took two math tests. He scored
- 62 out of 100 on 5-minute timed test of basic math facts, and
- 10 out of 10 on an untimely test measuring his performance in solving one-digit by one-digit addition problems.
Each of these tests measures a different skill and requires the performance of an entirely different set of tasks. Comparing the scores 10 and 62 tells us very little unless we have additional information (like the total number of items or the types of problems on each test), especially if the content on each test was very different.
For example, it would be difficult to compare the scores because the raw score tells us so little. Perhaps the score of 62 on the timed test was for your 2nd grader on all the basic multiplication facts in the 7, 8, and 9, and the score of 10 was on basic addition facts in the 1 and 2. Though your child scores 62 on the timed test, it would be a great score for most 2nd graders!
Standard scores are scores that have been standardized – scores that have been converted to a common scale.
Because the scores are on a common scale, they can be compared to scores from other tests with the same common scale. There are several types of standard scores. Generally, however, standard scores from 90 to 110 represent an average range.
Scaled scores are another type of standard score, generally used for reporting sub test performance.
Generally, in an individual special education assessment, many tests are administered. An entire group of tests over many subject areas is called a test battery while one specific test measuring a snapshot of a larger content area is called a sub test.
For example, a series of tests may be administered to determine a child’s performance in reading.
- The entire set of tests is called a reading battery.
- The individual tests within the battery are called sub tests.
Individual tests within the battery measure specific aspects of reading like
- sight word recognition,
- pseudo-word recognition (a list of fake words – used to test a child’s phonics skills),
- reading comprehension,
- Listening comprehension, and others.
Standard scores for the individual tests (sub tests) are called “scaled scores.” Scaled scores are reported as an indicator of a student’s performance in a specific area measured by the sub test. An average range for scaled scores is generally from 8 to 12.
Scaled scores can be compared to other scaled scores within the same battery, but may not be compared to scaled scores from another battery. However, because standard scores represent bundled scores (e.g., several sub tests combined), they may be compared to standard scores from another battery.
Using the raw score example above, if your child’s test scores were part of a battery and were converted to scaled scores, you would be able to meaningfully compare the two. If the child’s score on the multiplication test was 9 and his score on the addition test was 10, you would know that he performed within an average range on both tests! You would also know that he compared favorably with others of his same age and grade level.
Percentile Ranks indicate the rank order of the scores for a given test.
A percentile rank of 60 indicates that the test taker scored as well or better than 60% of the others who took the test, or that 40% of the test takers scored less well.
Remember, percentile ranks are not the same as percentages! A percentage indicates how many of the items were answered correctly when the raw score is divided by the total number of items on the test.
A percentile rank is the position of your child’s score when the scores of all test takers are ranked from highest to lowest.
Percentile ranks for the common special education assessments are based on the standard and scaled scores of those in the norm sample. The average percentile rank is 50 and an average rank is between the 25th and 75th percentiles.
The norm sample consists of all of the test takers who took the test for the publisher during test development.
Your child’s scores are compared to the scores of those individuals only. Many times parents misunderstand this comparison. It is not a comparison to others of the same age today, or to the others in his class, but to the group of individuals who took the test when the test was being developed.
However, because the scores are standardized, they may be compared to the scores of the other test takers on the same test (such as to the others in your child’s class, or to his siblings when they were in his grade), or to scores on other tests to see how well his performance in one academic area compares to another.
Most reputable tests have very large norm samples that include test takers from
- all over the country
- in all types of schools and with
- Various kinds of individual characteristics.
The degree to which individuals like your child were included in the norm sample is an indication of the likelihood that the comparison of your child’s score to the scores of others in that norm sample is valid and reliable. It is extremely important that the norm sample is “representative” of your child.
If others like your child are included in the norm sample, then the comparison of your child’s test scores to the scores of the test takers in the norm sample will be more valid and reliable. It is important that you evaluate the group to which your child is being compared.
Test publishers are often careful to include a wide variety of demographic characteristics in their norm samples. They attentively account for ethnicity, exceptionalism, culture, school type and location and other characteristics in their selection of test takers to include in the norm sample.
Use the following table to look up your child’s score and see where it in common standardized assessments used for special education.