Tennessee’s testing problems continue. This time the issue is missing students.

Students’ test scores are used to evaluate teachers, and the failure of a data processing vendor to include scores for thousands of students may have skewed results for some teachers, officials said.

The scores, known as TVAAS, are based on how students improved under a teacher’s watch. The scores affect a teacher’s overall evaluation and in some districts, like Shelby County Schools, determine if a teacher gets a raise.

The error affects 1,700 teachers statewide, or about 9 percent of the 19,000 Tennessee teachers who receive scores. About 900 of those teachers had five or more students missing from their score, which could change their result.

The latest glitch follows a series of mishaps, including test scanning errors, which also affect teacher evaluations. A delay earlier this summer from the Tennessee Department of Education’s testing vendor, Questar, set off a chain of events that resulted in the missing student scores.

To calculate a teacher’s growth score, students and their test scores are assigned to a teacher. About 3 percent of the 1.5 million student-teacher assignments statewide had to be manually submitted in Excel files after Questar experienced software issues and fell behind on releasing raw scores to districts.

RANDA Solutions, a data processing vendor for the state, failed to input all of those Excel files, leading to the teachers’ scores being calculated without their full roster of students, said Sara Gast, a state spokeswoman. The error will not affect school or district TVAAS scores. (District-level TVAAS scores were released in September.)

Gast did not immediately confirm when the state will finalize those teachers’ scores with corrected student rosters. The state sent letters to districts last week informing them of the error and at least one Memphis teacher was told she had more than 80 of her 120 students missing from her score.

In the past, the process for matching students to the right teachers began at the end of the year, “which does not leave much room for adjustments in the case of unexpected delays,” Gast said in an email. The state had already planned to open the process earlier this year. Teachers can begin to verify their rosters next week, she said.