This technical report provides detailed information regarding the technical, statistical, and measurement attributes of the New York State Testing Program (NYSTP) for the Grades 3-8 English Language Arts (ELA) and Mathematics 2018 Operational Tests. This report includes information about test content and test development, item (i.e., individual test question) and test statistics, validity and reliability, differential item functioning (DIF) studies, test administration, scoring, scaling, and student performance. The 2018 Grades 3-8 ELA and Mathematics NYSTP has been designed to measure student knowledge and skills as defined by grade-level New York State Learning Standards in ELA and Mathematics. The tests are designed to allow the classification of student proficiency into four performance levels (Level I, Level II, Level III, and Level IV). Likewise, the test provides students at each of these performance levels opportunities to demonstrate their knowledge and skills in the Learning Standards. [For "New York State Testing Program 2017: English Language Arts and Mathematics Grades 3-8. Technical Report," see ED601170.]