Reporting Overall Performance on CAST Interim Assessments

In addition to a scale score, an achievement level is provided for each student. Those achievement levels describe how student performance relates to standards of student performance provided in the 2018–19 California Science Test (CAST) standard setting study. A student is assigned to one of the three reporting categories:

  • Below Standard: The assessment results indicate that the student has not yet displayed sufficient evidence of understanding the standards measured by this test.
  • Near Standard: The assessment results may be just above, at, or just below the achievement level which indicates the student has met the standard for their grade level.
  • Above Standard: The assessment results indicate that the student understands and can apply subject-area knowledge to the standards measured in this test.

Student achievement levels are assigned on the basis of scale scores. Each CAST Interim Assessment form has its own scale score range. Scale scores provide a common reference between test administrations. The achievement levels should be understood as representing approximations of levels at which students demonstrate mastery of a set of concepts and skills as well as the concepts and skills associated with the scale scores just above and below the score received. An achievement level should be understood as a general band of performance.

  1. For middle school and high school interim assessments, the scale cut scores for the reporting categories were the same as those for the domain performance levels (referred to as the domain scale cut scores) in the summative assessment. The domain scale cut scores were established in the 2018–19 test administration based on the level 3 cut scores from the standard setting, and then reevaluated using the 2021–22 test administration data because of the revised test blueprint and the significant increase in item information. Detailed information about the standard setting study and the reevaluation study can be found in the Standard Setting Technical Report for the California Science Test (California Department of Education [CDE], 2019) and California Assessment of Student Performance and Progress California Science Test 2021–22 Technical Report (CDE, 2023).
  2. The CAST Interim Assessments for grades three, four, and five were built by grade level instead of by domains. As a result, the grade five domain scale cut scores from the summative assessments do not apply to these grade levels. The scale score ranges for the reporting categories for grades three, four, and five were calculated using a method analogous to how the domain scale cut scores were established on the basis of simulated student data.

The minimum and maximum scale scores for each achievement level vary for interim assessment forms. The scale score ranges and achievement levels for form I and form II are presented in table 1 and table 2.

Note the following abbreviations for table 1 and table 2:

  • MS = middle school
  • HS = high school
  • ESS = Earth and Space Sciences
  • LS = Life Sciences
  • PS = Physical Sciences

Table 1. Form I Scale Score Ranges for Achievement Levels
Grade Band Form Level 1 Lower Bound Level 1 Upper Bound Level 2 Lower Bound Level 2 Upper Bound Level 3 Lower Bound Level 3 Upper Bound
G3–5 G3 150 196 197 229 230 250
G3–5 G4 150 196 197 228 229 250
G3–5 G5 150 196 197 228 229 250
MS ESS 350 393 394 435 436 450
MS LS 350 400 401 430 431 450
MS PS 350 400 401 430 431 450
HS ESS 550 598 599 631 632 650
HS LS 550 598 599 629 630 650
HS PS 550 599 600 629 630 650

Table 2. Form II Scale Score Ranges for Achievement Levels
Grade Band Form Level 1 Lower Bound Level 1 Upper Bound Level 2 Lower Bound Level 2 Upper Bound Level 3 Lower Bound Level 3 Upper Bound
G3–5 G3 150 194 195 229 230 250
G3–5 G4 150 196 197 228 229 250
G3–5 G5 150 192 193 231 232 250
MS ESS 350 393 394 435 436 450
MS LS 350 400 401 430 431 450
MS PS 350 400 401 430 431 450
HS ESS 550 598 599 631 632 650
HS LS 550 598 599 629 630 650
HS PS 550 599 600 629 630 650

Standard Error of Measurement

CAST Interim Assessments provide the most precise scores possible, but no assessment can be 100 percent accurate. Each test score reflects a combination of both student skill and factors unrelated to that skill. Unrelated factors can include the sample of items included on the assessment, the student’s mental or emotional state on the testing day, the student’s luck in choosing more correct answers than incorrect answers when guessing, the conditions under which the student took the assessment, and many others.

The standard error of measurement (SEM) is an evaluation of the degree to which a student’s test score is expected to change across administrations of parallel test forms because of unrelated factors. The SEM is useful in describing a range for which a student’s actual level of skill is likely. The SEM is accounted for in the student test results by the error bands. The error band indicates a statistical range of scores that the student would theoretically achieve if they were to take the assessment multiple times.