As with many standardized assessments, the STAAR program uses scale scores to communicate
information about performance levels. A scale score is a more exact way to determine subject
mastery than a raw score because a scale score considers the difficulty level of each individual
test question in addition to whether a student answers the question correctly. The basic score on
any test is the raw score, which is the number of questions answered correctly regardless of
difficulty level. A scale score is a conversion of the raw score onto a scale that takes into account
the difficulty level of the specific set of questions used on a test in any given year. A scale-score
system allows every test to have exactly the same passing standard, or level of performance
required, even though the raw score needed to pass the test may vary slightly from year to year.
When building new tests each year, it is not always possible to select questions that have exactly
the same difficulty as questions on previous versions of the test. Maintaining the passing standard
(but not necessarily the raw score needed to pass) from year to year is important to ensure that
students passing in one year will have exactly the same rigorous testing requirements as students
passing in a subsequent year, even though the test questions differ from one year to the next.