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Comparing California Standards Test (CST) Results

When comparing results for the CSTs, compare results only within the same subject and grade, that is, grade two English-language arts compared to grade two English-language arts or grade six mathematics compared to grade six mathematics. No direct comparisons should be made between grades or between content areas.

Two types of comparisons are possible: 1) comparing the average scale score or 2) comparing the percentage of students scoring at each performance level. The reviewer may compare results for the same grade and subject across years within a school, between schools, or between a school and its district, county, or the state. When making comparisons, the reviewer should consider comparing the percentage of students scoring proficient and advanced, since the state target is for all students to score at or above proficient.

Comparing California Achievement Tests, Sixth Edition Survey (CAT/6 Survey) Results

See "Term and Score Explanations" for an explanation of national percentile ranks (NPRs).

When comparing CAT/6 Survey results, compare results only within the same subject. The most defensible comparison is the Percent of Students Scoring At or Above the 50th NPR. This is the percentage of students in the group purported to have demonstrated achievement at or above grade level and tells you the percentage of students in the tested group that scored at or above the score achieved by half (50%) of the students in the national sample (norm group). If the percent of students that scored at or above the 50th NPR is greater than 50, the group performed better than the national sample. The percentages of students that scored at or above the 50th NPR can be compared between and among schools and school districts, as well as used to compare a school's test results to those of its school district, county, or the state.

The grade three or grade seven results can be compared from year to year, either by comparing within grade and subject the percentage of students scoring at or above the 50th NPR or by comparing the mean scale score from year to year. When making comparisons across years, it is important to understand that even when the number of students is the same that the group's composition from year to year may be quite different if student mobility (transiency) is high. Generally there will be more variance in scores from year to year when small numbers of students are tested.

Comparing Aprenda: La prueba de logros en español, Tercera edición (Aprenda 3) Results

A reviewer may compare the performance of students at different grade levels within a school on the Aprenda 3. Similarities and differences in student performance in the same subject may be seen by comparing the Percent of Students Scoring at or Above the 50th NPR for each grade. When making this comparison, it is important to remember that the number of students in the group affects the confidence of the inferences that can be made. The smaller the group the more cautious one should be in making comparisons. It is also important to note that the national norm groups to which California's Spanish-speaking English learners' scores are compared were unique for each grade level.

Like the CAT/6 Survey, the most defensible comparison is the Percent of Students Scoring At or Above the 50th NPR. This is the percentage of students in the group purported to have demonstrated achievement at or above grade level in Spanish and tells you the percentage of students in the tested group that scored at or above the score achieved by half (50%) of the students in the national sample (norm group). If the percent of students that scored at or above the 50th NPR is greater than 50, the group performed better than the national sample. The percentages of students that scored at or above the 50th NPR can be compared between and among schools and school districts, as well as used to compare a school's test results to those of its school district, county, or the state.

California Department of Education