Thursday, January 3, 2013

Understanding Your Child’s Standardized Test Scores

Understanding speech and language testing scores can bring you back to the basics of statistics and the bell curve.  Typically, speech-language testing scores are based on normative sampling in which test makers administer the test to a large group of children.  Your child’s scores are compared to the sample to see how their skills compare to peers.  With most speech-language tests, you can expect to derive the following scores:
Raw Score:  The raw score is typically either the total number correct or the total number of errors. 

Standard Score:  The standard score is determined by the raw score and is a conversion that allows for comparison to the normative sample.  The median standard score is 100.  The standard score and percentile rank essentially provide the same information, but most people find the percentile rank to provide a clearer benchmark for their child. 

Percentile Rank:  The percentile rank is also determined by the raw score.  It tells you the percentage of peers your child scored above.  For example, a percentile rank of 40% means that your child performed higher than 40% of peers.  The median percentile rank is 50%.  The following guideline can be used for understanding the significance of percentile ranks:

Below Average
Your child may have a severe delay.
Low Average
Your child may have a mild or moderate delay.
High/Above Average
Your child does not have a delay.

Test Age-Equivalent:  A test age equivalent is also derived from the raw score.  It indicates the age to which your child’s skills can best be most compared.  This score should be interpreted with some caution since sometimes a delay in skills also involves a difference in skills.  For instance, a child who is 4 years old and receives an age-equivalency of 3 years old may present differently than a typical 3-year-old child.  Age equivalencies are best used as severity measures for this reason.