Formal spelling assessments are given to students throughout the year to track their progress. These assessments include achievement tests to determine their instructional level, diagnostic tests to assess learned words and skills, and criterion-referenced tests used to measure learning before and after instruction. Informal spelling assessments, such as dictated spelling tests and spelling inventories, are also used by teachers to evaluate students' literacy skills and identify strengths and weaknesses in spelling. Successful spelling requires students to use phonics, visual cues, and knowledge of high-frequency words when writing to check for correctly spelled words. The goal is for students to become proficient spellers and writers.