The California Science Test (CAST) is a computer-based assessment required for all students in grades five and eight and once in high school. The purpose of the CAST is to measure students' achievement of the California Next Generation Science Standards (CA NGSS) through the application of their knowledge and skills of the Science and Engineering Practices, Disciplinary Core Ideas, and Crosscutting Concepts. 

The assessment consists of stand-alone questions or discrete items and performance tasks (PT).

• The discrete item types consist of selected response, constructed response, table fill-in, and graphing.
• The performance tasks (PTs) measure a student's ability to integrate knowledge and skills across multiple standards through extended activities.