The Scale Score is the basic score for TerraNova and other CTB assessments. It is used to derive all the other scores that describe test performance. Scale Scores can be obtained by one of two scoring methods. With item-pattern scoring, Scale Scores are derived numerically using all the information contained in a student's pattern of item responses. The second method is number correct scoring.
Customers can choose to use either scoring method.
CTB recommends item-pattern scoring because it provides more accurate results for individual students. Scale Scores are equal-interval scores that can be averaged and used in other statistical analyses. The NP represents the percentage of students in the national norm group whose scores fall below a given student's score. For example, a student whose NP is 65 scored higher than 65 percent of the students in the norm group. NPs are scores that are useful for comparing local student achievement to students' achievement nationally.