A standard deviation (SD) is a quantity derived from the distribution of scores from a normative sample. The standard deviation is the average distance (or deviation) from the mean. Read More
Category: Normative/Standardization Sample
These terms are basically synonyms. Standardization sample is the term more frequently used in statistics and normative sample is more common within psychometrics. The individuals participating in the standardization study (i.e., standardization sample) take the test or measure to be normed during test development. The resulting scores/performances determine what is considered normal or typically developing performance for that test. Most commercially available tests use a standardization sample that reflects the most recent U.S. census information. This means minorities and culturally or linguistically diverse children are present only in small numbers.
Understanding Assessment: Problems with Percentile Rank and Age Equivalency
The percentile rank of a score is percentage of total scores from the normative sample that were equal or lesser than the value of the score. It can be plotted on the bell curve of a normal distribution. Read More
Understanding Assessment: Understanding the Normative Sample
The terms normative sample and standardization sample refer to the same concept and are often used interchangeably, though standardization sample is the term more frequently used in statistics and normative sample is more common within psychometrics. A norm referenced test uses a normative or standardization sample from the general population to determine what is “typical” or “normal” in that population. Read More
Understanding Assessment: Understanding the Standard Error of Measure
The standard error of measure indicates the amount of uncertainty that a sample (such as a normative sample) is truly representative of the general population. In the case of administering standardized tests, it conveys the level of uncertainty that a single test performance observed by the evaluator represents how the child would do if it were administered multiple times. Read More
