The Unified Scale accomplishes two different objectives. First, it links Star Early Literacy to the Star Reading Enterprise scale. Second, it creates a new scale, applicable to Early Literacy, Reading, and Maths, that has the desirable measurement properties of a Rasch score scale. The Unified Scale provides you with increased measurement precision and one consistent scale across all computer-adaptive Star assessments.
Educators have requested that students taking Star Reading and Star Early Literacy be placed on the same scale. In the Enterprise scale, Star Reading and Star Maths had a scale score range of 0–1400, while Star Early Literacy was on a different scale with a score range of 300–900.
In response to the need for one scale, Renaissance developed the "unified score scale" that can be used to report scores for both Star Early Literacy and Star Reading (as well as Star Maths). The Unified Scale score ranges from 0 to approximately 1400; Star Early Literacy scores range from 200–1100 and Star Reading and Star Maths range from 600–1400. Note that a single score does not apply across all programs—for example, a student having a score of 900 in Star Early Literacy cannot automatically be assumed to have the same score in Star Reading or Star Maths.
A note of caution is necessary here to discourage over-interpretation of this unified score scale: Although Star Early Literacy and Star Reading Enterprise are fairly highly correlated, they measure different aspects of the progression from pre-literacy to fully-developed reading proficiency. Consequently, the highest claim that can be made about the Star Early Reading Rasch scores and scale scores is that they identify new Star Early Literacy scores that are approximately equivalent to Star Reading scores.
Related video: AssessMinutes—Unified Scale