Different Types of Scores on Standardized Tests

A standardized test score is usually represented as a number indicating how well a child performed on an assessment. There are a number of different types of scores used in educational testing. Test scores can either be norm-referenced (comparing kids to others the same age) or criterion-referenced (assessing a child's performance on a specific task).

Learning disabilities are often diagnosed and assessed using norm-referenced scores. These types of scores estimate whether a student's scores are above average, average, or below average compared to his or her peers. Test results are also often used to gauge how well a child is doing and to decide if a child needs extra help in specific areas.

Types of Standardized Test Scores

There are many different types of test scores used in educational testing. Common ones you may encounter on your child's school reports, particularly in special education and learning disability assessments, include the following.

Standard Scores

Test developers calculate the statistical average based on the performance of students tested in the norming process of test development. That score is assigned a value. Different performance levels are calculated based on the differences in student scores from the statistical average and are expressed as standard deviations.

These standard deviations are used to determine what scores fall within the above average, average, and below average ranges. Standard scores and standard deviations are different for different tests. Many of the commonly used tests, such as the Wechsler Intelligence Scales, have an average score of 100 and a standard deviation of 15.

Percentiles

These scores show how a student's performance compares to others tested during test development. A student who scores at the 50th percentile performed at least as well as 50 percent of students his age. A score at the 50th percentile is within the average range.

Z-Scores

These scores are scaled on a number line ranging from -4 to 4. On this scale, zero is average. Positive scores are above average, and negative scores are below average.

T-Scores

These scores range in intervals of 10 from 10 to 90 points. Fifty is average on this scale, and the average range is usually between 40 and 60.

Stanine Score

The stanine scale is also called the standard nine scale. These scores range from 1 to 9, with 5 being average. Scores below 5 are below average. Scores above 5 are above average.

Scaled Scores

This type of test score involves presenting different scores on a number of subtests, each of which assesses a specific skill or area. In many cases, these scaled scores are then combined in order to arrive at an overall composite score. 

Some test publishers create their own scales of standard scores. Interpretations of those scales are typically available through your child's examiner.

How Test Scores Are Used

Schools and parents use the information gleaned from these test scores to make decisions about a child's education.

Identifying Challenge Areas

Schools utilize these different types of scores to identify academic strengths as well as to find areas where a student may need a little extra help. A single test may provide a number of different scores, each representing a different area of interest.

For example, a reading test might contain different scores for vocabulary, phonemic awareness, fluency, and comprehension. Other areas that tests might assess include working memory, vocabulary, processing speed, verbal reasoning, problem-solving, and listening comprehension.

Students might score well in some areas, but perform more poorly in others. Knowing how a child performs on these types of tests, as well as how their performance compares to other kids their own age, can give parents and educators more information about what a child may need in order to succeed academically.

Determining Eligibility for Specialized Help

These scores can also be used to determine if children require and can gain admission to a particular program. For example, a student might need to score below the 25th percentile on a norm-referenced test in order to qualify for a special education program.

A Word From Verywell

These common types of standard scores can help estimate your child's performance. Your child's special education teacher, counselor, or school psychologist can provide you with information on these or any other tests taken at school. Ask questions if you have them. You are your child's best advocate, and understanding the minutiae of standardized testing can help you decide what's right for your child.